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Effectiveness of a parent-implemented intervention program for young children with cleft palate
International Journal of Pediatric Otorhinolaryngology 79 (2015) 707–715
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International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Effectiveness of a parent-implemented intervention program for young children with cleft palate§ Seunghee Ha * Division of Speech Pathology and Audiology, Audiology and Speech Pathology Research Institute, Hallym University, Republic of Korea
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 January 2015 Received in revised form 18 February 2015 Accepted 19 February 2015 Available online 26 February 2015
Objective: This study investigated the effectiveness of a parent-implemented intervention on children’s speech-language development and parents’ interaction styles. Methods: Seventeen children with cleft palate (CP) and their mothers participated in all sessions of a parent-implemented intervention program. Nine children with CP and their mothers who did not receive the intervention were included to examine the full effectiveness of the program. The intervention program consisted of four phases, pre-intervention test, parent training, parent-implemented intervention at children’s home for 3 months, and post-intervention test. Children’s language and speech measures and maternal measures from pre- and post-intervention tests were compared between groups (intervention vs. no intervention). Results: Children who received a parent-implemented intervention exhibited significant improvement in language measures based on standardized tests and quantitative language and speech measures from spontaneous utterances. The children in the intervention group showed a significantly greater extent of change in expressive vocabulary size, number of total words, and mean length of utterance than did those who did not receive the intervention. Mothers who received the training showed a significantly decreased number of different words, increased responsiveness, and decreased non-contingent utterances for children’s communication acts compared to those who did not receive the training. Conclusions: The results of the study support the effectiveness of parent-implemented early intervention on positive changes in children’s speech-language development and mothers’ use of communication strategies. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Children with cleft palate Parent-implemented intervention Speech-language development Babies–mothers interaction Speech therapy Compensatory speech errors
1. Introduction A number of studies over the past 20 years have shown that children with cleft palate (CP) demonstrate a variety of speechlanguage impairments [1–16]. Deficits in the onset and composition of their babbling emerge during the prelinguistic period [1–3]. The literature also reports that the deficits in early vocalization in children with CP have cascading effects on their subsequent speech and lexical development [4–6]. The restricted diversities of
§ This study was conducted as an extend study of Ha (2013) published at Korean Journal of Speech-Language and Hearing Disorders and part of the study was presented at the 71st Annual Meeting of the American Cleft Palate-Craniofacial Association, Indianapolis, Indiana, March, 2014. * Correspondence to: Division of Speech pathology and Audiology, Audiology and Speech Pathology Research Institute, Hallym University, Life Science Hall # 8606, 39 Hallymdaehak-gil, Chuncheon-si, Kangwon-do, Republic of Korea. Tel.: +82 332482215. E-mail address: [email protected]
http://dx.doi.org/10.1016/j.ijporl.2015.02.023 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
sounds and phonetic structures of early vocalization result in late onset of first words, limited lexical development and consonant inventories, and the emergence of compensatory articulation errors. A substantial number of children with CP are reported to have persistent speech-language problems during the preschool period [16]. Studies describing deficits of early vocalization and later speech-language development in children with CP highlight the need to develop and provide early intervention programs for this population. Effective early intervention for children with CP reduces language and speech problems and the need for more intensive clinician-implemented intervention. The literature supports the efficacy of early intervention programs on improving expressive language and speech performance in young children with CP [17–22]. Efficacy of early intervention has led clinicians and researchers to develop various early intervention programs and service-delivery models for children with CP. Research also suggests that parental involvement is an essential component of effective early intervention programs for young children prior to 3 years of age. On a practical level, it
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appears difficult to provide infants and toddlers with direct and clinician-implemented therapy because it demands attention and cooperation from the children. Such therapy could obtain maximum gains if well-trained parents deliver intervention skills in natural environments following the levels and durations of children’s attention and interest. Many studies on early language intervention have demonstrated that parents can be trained to use language stimulation skills, including modeling and appropriate responses during daily life interactions [17–20]. These parentimplemented intervention programs lead to an expansion of children’s vocabulary and speech sound inventories. Pamplona and Ysunza supported the concept that active participation of mothers during speech therapy yields better therapy outcomes for language skills than do clinician-implemented speech therapy given to 3–4year olds with CP [19]. Scherer and colleagues explored the effectiveness of a parentimplemented, focused stimulation program on the speech characteristics of children younger than 3 years with cleft lip and palate [20]. Mothers were trained to deliver the intervention reliably, which yielded positive changes in language and speech performance in children with cleft lip and palate. In particular, the researchers found increased sound inventories, increased speech accuracy, and decreased use of glottal stops as the main outcomes of the intervention. Although the researchers included a comparison for typically developing children without CP at the same language development level, their study did not provide a prospective comparison between children with CP who did and did not receive the intervention over the same time interval. Therefore, it is necessary to conduct further studies to provide empirical evidence to validate a parent-implemented intervention program. Such study should include a control group to exclude the possible ongoing results of natural maturation and growth. The purpose of this study was to investigate the effectiveness of a parent-implemented intervention program for young children with CP. The effectiveness of this intervention program was determined based on changes in speech-language performance of children with CP and mothers’ use of communication strategies compared to children with CP and mothers who did not receive the parent training. 2. Methods 2.1. Participants Seventeen children with non-syndromic CP and their mothers participated in all study sessions, including parent training, parent-implemented intervention in the children’s homes over a 3-month period, and pre- and post-assessment procedures. Originally, 22 children with CP and their mothers received the initial assessment and parent training. However, 4 mothers could not complete the parent-implemented intervention and withdrew from the study. Another child was diagnosed with velocardiofacial syndrome following the intervention program; therefore, the data from this participant were excluded from this study. Nine children with non-syndromic CP and their mothers were included as a control group that received no intervention to compare the effects of the program against the course of natural development in children with CP over the same period. The mother–child pairs in the control group attended only two assessment sessions administered within a 3-month interval. No child with CP in either group had significant medical or neurological impairments or genetic syndromes, as evidenced in the medical history form. According to parents’ report, each child had history of otitis media and received ear tubes at the time of primary palate repair. Table 1 shows the children’s genders, ages at the time of the initial assessment, cleft type, and age at palatal
surgery. The data also included mothers’ ages and years of public education for both the intervention and control groups. The intervention group included 10 girls and 7 boys, ranging in age from 13 to 29 months (mean = 19.5 months) at the time of the study initiation. The control group included 5 girls and 4 boys, ranging in age from 13 to 23 months (mean = 16.4) at the time of study initiation. A t-test comparison showed no significant differences in children’s ages between groups (t = 1.797, df = 24, p = .085). Mothers in the intervention group ranged in age from 26 to 41 years, and the mothers in the control group ranged in age from 28 to 40 years. All mothers had completed education beyond high school. No child had previously enrolled in any speechlanguage intervention. However, mothers reported receiving information about the effects of clefting on speech and language development through local craniofacial clinics. Mothers also received information on simple interaction skills to stimulate speech and language development in their children. A formal Institutional Review Board at the researcher’s university was not available when the present study was initiated. However, the principles outlined in the Declaration of Helsinki were followed, and signed consent forms were obtained from all the children’s parents before collecting the data. All children and their parents participated in the study voluntarily, and they were allowed to withdraw from the study if they chose. 2.2. Assessment procedures All mother–child pairs participated in two assessments conducted at 3-month interval. Standardized tests and two 20min video and audiotaped language samples obtained in participants’ homes provided the data. The two 20-min language samples involved mother–child and evaluator–child interactions, respectively. The standardized tests included (1) a Sequenced Language Scale for Infants (SELSI) [23] to provide a receptive and expressive language age score and (2) Korean MacArthur-Bates Communicative Development Inventories (KM-BCDI) [24]. The language samples were collected while children interacted with their mothers and an evaluator during free play with toys and bookreading activities. The same toys and books were used during the pre- and post-assessment sessions. Two graduate students majoring in speech pathology and trained for this study were involved as evaluators. Mothers were instructed to play with their babies as they typically interacted in their homes. The language sample that included evaluator–child interaction was collected following the mother–child interaction. 2.3. Child production measures From the middle of the two 20-min language samples from evaluator–child and mother–child interactions, we selected two 15-min segments, and the resulting 30-min language samples from each participant were included in the analysis. Several trained graduate and undergraduate students in a speech pathology program transcribed and analyzed the language samples. The transcribers and analyzers were blinded to the purpose of the study and its sampling conditions (e.g., treatment phase). Undergraduate students first performed orthographic transcriptions of each language sample. The researcher and two graduate students who collected the data examined the accuracy of the transcriptions. Two graduate students performed phonetic transcriptions of children’s language samples. If disagreement occurred between the two transcribers, the researcher and two graduate students listened to and examined the parts together to determine the final transcription for the data analysis. The children’s measures included (1) language age score for SELSI [22], (2) number of expressive vocabulary from the
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Table 1 Participant characteristics for the children with cleft palate and their mothers in both groups. Group
No.
Child Gender
Age (months)
Cleft type
Age at palate repair (months)
Age (years)
Years of education
Intervention
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
F F F F F F F F F F M M M M M M M
18 13 29 22 25 18 13 20 21 18 15 22 27 17 16 19 18 19.5
UCLP CP CP CP UCLP CP UCLP UCLP CP UCLP UCLP UCLP BCLP UCLP UCLP UCLP UCLP
12 12 18 11 18 13 12 13 11 11 11 12 12 11 11 11 11 12.4
35 31 31 35 35 33 33 34 36 31 35 29 32 36 41 28 41 33.3
16 12 16 16 12 16 16 16 12 16 16 12 14 14 16 16 16
1 2 3 4 5 6 7 8 9
F F F F F M M M M
23 13 18 19 15 15 15 16 15 16.4
CP CP CP UCLP CP UCLP UCLP UCLP BCLP
16 10 12 10 12 11 11 11 13 11.6
33 40 35 30 31 30 41 28 46 34.9
12 12 18 16 16 14 16 16 12
Mean Control
Mean
Mother
Note: UCLP = unilateral cleft lip and palate; BCLP = bilateral cleft lip and palate; CP = cleft palate; F = female; M = male.
administration of KM-BCDI [23], (3) percentage of each communication mode for gesture, vocalization, and intelligible speech, (4) total number of words, (5) number of different words, (6) mean length of utterances (MLU), (7) number of true consonants, and (8) percentage of compensatory misarticulations. In terms of measures of communication mode, intelligible speech indicated that children’s utterances were phonetically similar or identical to the adult target in terms of syllable shape and segmental patterning; therefore, they were linked systematically with the contexts. True consonants included all consonant sounds, except glottal stops and glides, based on Stoel–Gammon’s definition [25]. 2.4. Parent language measures The maternal measures were related to the length and complexity of utterances using quantitative measures and communication functions. The maternal quantitative measures included (1) total number of utterances, (2) total number of words used, (3) number of different words, and (4) the MLU. A list of communication functions was modified and defined using the communication strategies and types suggested in previous studies [26–28]. The communication functions included five categories, (1) responding, (2) non-contingent utterances, (3) requesting and asking, (4) suggesting, and (5) other functions (e.g., calling, attention getter, or prohibiting). Responding was analyzed in detail to classify the subtypes as the communication function, which has been reported to have positive effect on children’s language development in the literature [27–30]. The subtypes of responding included linguistic mapping, correcting children’s unintelligible speech (corrective feedback), and expansions. Non-contingent utterances involved mothers’ verbal comments on behaviors or objects far from their children’s attention and interest during the interactions. These functions were considered less effective on children’s language development; therefore, they were separated from responsiveness. The
pre- and post-intervention test sessions were compared on the percentage of each category of communication function in the mothers’ language samples. 2.5. Parent-implemented intervention The intervention program consisted of parent training and parent-implemented intervention at home during a 3-month period. Parents in the intervention group participated in individualized or small group training conducted one week after the initial assessment. The content and procedures of the parental training were developed based on a careful review of previous studies [26– 34] on early interventions for various populations, including children with CP. Parent training consisted of a description of language-speech characteristics of children with CP, listening to audio samples of speech problems (i.e., hypernasality and compensatory articulation errors) caused by CP and velopharyngeal dysfunction, and instruction of language stimulation skills and communication strategies. In particular, the researcher selected 11 communication strategies for the training, and parents could easily follow these strategies at home. The communication strategies included (1) face-to-face parent-child communication, (2) following a child’s interests, (3) emphasizing the initial oral sound of words, (4) exaggerating lip movements, (5) speaking slowly, (6) repeating words, (7) using short and simple expressions, (8) waiting for the child’s response, (9) listening to the child’s speech, (10) responding to the child’s speech immediately, and (11) providing immediate and appropriate verbal feedback that included modeling or expanding on the child’s speech except for compensatory articulation. Using these communication strategies, mothers were taught to create episodes of joint attention and action to generate child-oriented responses and to optimize linguistic responsiveness. These strategies addressed the child’s interests and delivered communicative attempts to stimulate language development.
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Table 2 Comparison of language performance for children in the intervention and control groups. Measurement
Group
Mean
Median
Range
Mean
Median
Range
SELSI-EA (months)
1 2 1 vs. 2
13.9 13.1
13 13 70.00
5–22 7–18
19.2 15.4
19 14 44.00
12–29 10–24
1 2 1 vs. 2
16.1 8.2
6 5 72.00
0–110 0–27
79.4 21.2
46 8 27.00**
7–249 0–109
3.52** 1.61
1 2 1 vs. 2
25.9 30.2
11 14 58.50
0–150 1–112
65.6 43.1
34 40 70.00
1–235 0–131
2.49* 1.19
1 2 1 vs. 2
23.5 15.1
10 6 75.50
0–167 0–54
61.9 14.4
29 20 44.00
0–294 0–31
2.47* .00
1 2 1 vs. 2
5.0 3.2
2 2 72.50
0–32 0–14
12.3 5.1
4 5 64.50
0–60 0–15
2.99** 1.85
1 2 1 vs. 2
0.79 0.91
1.00 1.00 63.00
.0–1.20 .0–1.07
1.00 1.00 49.00
1.0–1.33 .0–1.07
2.50* 0.96
U Vocabulary size on KMBCDI U # of total utterances U # of total words U # of different words U MLU U
Pre
Post
1.07 0.79
Z Pre vs. Post 3.64** 2.71**
Note: Group 1 = intervention study group; group 2 = control group (no intervention). SELSI-EA = expressive language age score in months on the SELSI; MLU = mean length of utterance. * Statistical significance, p < .05. ** p < .01.
The program also considered the speech characteristics of children with CP (i.e., preferring posterior sounds) and taught mothers to model oral anterior sounds by exaggerating lip movements. Language stimulation skills and communication strategies were introduced in detail using 4 video clips created in the researcher’s lab. The average duration of video clips, which demonstrated target skills and strategies, was 5 min. Mothers also received individualized coaching based on their videotaped interactions during the pre-assessment. The training session lasted approximately 3–4 h and included educational video clips. Mothers in the intervention group delivered a parent-implemented intervention program in their homes after the parent training over a 3-month period. A checklist of the communication strategies was created and given to mothers. Mothers were asked to indicate how long they worked with their child each day and whether they considered and used the communication strategies when interacting with their children. All mothers in the intervention group were monitored and coached biweekly over the 3 months via telephone and they were also encouraged to send video clips of their interactions with their children once a month so they could receive regular and specific instruction and further coaching.
3. Results 3.1. Children’s measures Tables 2–5 show the language and speech performances of children with CP in the two groups prior to and following the intervention program. The results indicated that children in the intervention group showed significant increases in expressive language age (Z = 3.64, p < .01) on the SELSI and number of expressive vocabulary (Z = 3.52, p < .01) on the KM-BCDI. In addition to the results based on the administration of standardized tests, certain language and speech outcomes based on the analysis of spontaneous speech samples showed positive changes following the intervention program. Children in the intervention group showed significant improvement in the number of total utterances (Z = 2.49, p < .05), number of total words (Z = 2.47, p < .05), number of different words (Z = 2.99, p < .01), and MLU (Z = 2.50, p < .05) following the intervention. Regarding communication modes, children in the intervention group used fewer gestures (Z = 2.84, p < .01) and more intelligible speech (Z = 2.65, p < .01) following the intervention. In
Table 3 Comparison of the communication mode percentages for children in the two groups. Measurement
% Gesture U % Vocalization U % Intelligible speech U
Group
Pre
Post
Z
Mean
Median
Range
Mean
Median
1 2 1 vs. 2
45.1 47.0
42 59 73.00
19–85 10–78
28.0 38.0
27 40 51.00
2–68 2–66
1 2 1 vs. 2
43.2 47.0
41 35 63.50
15–75 10–78
46.0 43.3
45 47 72.50
5–93 18–66
1 2 1 vs. 2
11.8 11.4
6 8 71.00
0–50 0–39
25.9 18.7
16 12 60.00
1–67 0–80
Note: Group 1 = intervention study group; group 2 = control group (no intervention). ** p < .01.
Range
Pre vs. post 2.84** .77
.40 .06 2.65** .53
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Table 4 Comparison of speech performance for children in the two groups. Measurement
Group
Pre Median
Range
Mean
# of true consonants
1 2 1 vs. 2
5.1 3.6
4 2 62.50
0–16 2–9
8.5 4.4
1 2 1 vs. 2
14.4 3.56
25.0 0 58.00
0–72 0–19.3
Mean
U % Compensatory misarticulations U
Post
Z
13.1 7.6
Median
Range
6.5 3 39.00*
1–18 1–12
23.6 0 69.50
0–61 0–33.3
Pre vs. post 3.38** 1.38
.42 .67
Note: Group 1 = intervention study group; group 2 = control group (no intervention). * Statistical significance, p < .05. ** p < .01. Table 5 Group comparison of the difference in children’s measures between pre- and post-assessments. Measurement
Group
Intervention
SELSI-EA (months) Vocabulary size on KMBCDI # of total utterances # of total words # of different words MLU # of true consonants % compensatory misarticulations Communication mode % Gesture % Vocalization % Intelligible speech
Control
U
SD
Mean
SD
4.52 63.29 39.65 38.35 7.29 .28 3.35 1.25
1.74 60.01 64.47 64.88 10.49 .43 3.06 17.50
3.22 13.00 12.89 .67 1.89 .12 .89 4.07
1.64 26.93 25.70 13.81 2.67 .60 1.83 14.63
45.00 23.00** 57.50 35.00* 59.50 34.00* 42.00 65.00
17.06 2.76 14.18
21.77 31.39 19.50
9.0 1.78 7.22
27.74 23.82 16.76
60.00 75.00 55.00
Mean
Note: SELSI-EA = expressive language age score in months on the SELSI; MLU = mean length of utterance. * Statistical significance, p < .05. ** p < .01.
addition, children in the intervention group exhibited significant increases in the number of true consonants (Z = 3.38, p < .01). On the other hand, children who did not receive the parentimplemented intervention showed a significant increase in only expressive language age (Z = 2.71, p < .01) on the SELSI 3 months later. Further, the children in the control group exhibited no significant changes in other language and speech measures over the same period. The statistical comparison of the two groups showed no significant differences on all measures of language and speech performance at the initial assessment. Following the intervention, the intervention group showed a significantly greater number of expressive vocabulary on the KM-BCDI (U = 27.00, p < .01) and greater number of true consonants (U = 39.00, p < .05) compared to the control group. The means and standard deviations of delta values between the measures of the pre- and post-assessments for each child in the two groups were calculated to determine whether children in the intervention group showed significantly greater change after the intervention program compared to children in the control group (see Table 5). Children in the intervention group made significant improvements on measures of vocabulary size on the KM-BCDI (U = 23.00, p < .01), number of total words (U = 35.00, p < .05), and MLU (U = 34.00, p < .05) compared to those in the control group. Although group differences did not reach statistical significance, children in the intervention group demonstrated greater increases in the use of intelligible speech and number of true consonants compared to the control group. The intervention group also showed a decrease in the percentage of compensatory misarticulation following the intervention, whereas the control group showed an increase in the percentage of compensatory misarticulation.
3.2. Maternal measures Changes in mothers’ use of language were determined and used to investigate the effectiveness of the parent-implemented intervention for young children with CP. Table 6 shows the results associated with mothers’ forms and content of language in the two groups at the initial and final assessments administered 3 months apart. Except for the number of different words, changes in mothers’ uses of language over time were not obvious in either group. Mothers in the intervention group used significantly fewer number of different words with their children after the intervention (Z = 2.64, p < .01). In contrast, mothers in the control group used significantly more words (Z = 2.19, p < .05) with their children at the final assessment. Table 7 displays the percentages of all communication functions for mothers in the two groups at the pre- and postassessments. A comparison of pre- and post-measures indicated that mothers in the intervention group significantly increased the percentage of responding (Z = 3.25, p < .01) and decreased the use of non-contingent utterances (Z = 2.79, p < .01). Among the subtypes of responding function, mothers in the intervention group used more expansions (Z = 2.39, p < .05) and corrective feedback (Z = 3.52, p < .01). However, mothers who did not receive the training showed no changes in communication functions over the two assessments. The statistical comparison of the two groups showed that mothers in the intervention group used significantly more words (U = 36.50, p < .05) and a significantly lower percentage of responding (U = 40.00, p < .05) compared to mothers in the control group at the pre-assessment. On the other hand, mothers in the intervention group used fewer different words (U = 38.00, p < .05), had greater MLU (U = 32.50, p < .05), a higher percentage of
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Table 6 Group comparison of measures on mothers’ utterances prior to and following the intervention period. Measurement
Group
Mean
Median
Range
Mean
Median
Range
# of total utterances
1 2 1 vs. 2
232.82 190.11
222 176 42.00
125–426 98–449
249.29 247.11
228 222 75.50
144–457 177–384
0.45 1.96
1 2 1 vs. 2
724.00 529.67
701 459 36.50*
426–1299 309–1069
669.41 610.56
629 557 60.50
437–1135 442–845
0.54 1.01
1 2 1 vs. 2
211.18 141.89
160 139 42.00
106–808 87–192
145.41 220.67
145 177 38.00*
109–205 106–622
2.64** 2.19*
1 2 1 vs. 2
2.88 2.74
2.74 2.56 62.00
2.18–4.06 1.93–4.04
2.71 2.40
2.62 2.40 32.50*
2.22–3.44 2.01–3.25
1.28 1.72
U # of total words used U # of different words U MLU U
Pre
Post
Z Pre vs. post
Note: Group 1 = intervention study group; group 2 = control group (no intervention). * Statistical significance, p < .05. ** p < .01.
mothers in the intervention group used significantly less different words following the intervention program while mothers in the control group used an increased number of different words 3 months later. In terms of mothers’ use of communication functions, following the intervention program, the two groups differed significantly in responding (U = 26.60, p < .01), noncontingent utterances (U = 24.00, p < .01), and corrective feedback (U = 31.50, p < .01). Mothers in the intervention group showed an increased use of responding and corrective feedback, whereas they showed a decreased use of non-contingent utterances. In contrast, mothers in the control group showed a decreased use of responding and an increased use of non-contingent utterances.
responding (U = 40.00, p < .05), and corrective feedback (U = 31.50, p < .05) compared to mothers in the control group at the postassessment. Table 8 shows the means and standard deviations of delta values for all maternal measures, which included differences between the pre- and post-assessments measures for all mothers in both groups. Mann–Whitney U tests were conducted to determine whether mothers in the intervention group changed significantly more compared to the control group following the intervention. This statistical analysis revealed that following the intervention program, the two groups differed significantly in number of different words (U = 14.50, p < .01). Specifically,
Table 7 Group comparisons for mothers’ communication function prior to and following the intervention period. Measurement (%)
Responding U Non-contingent U Asking/requesting U Suggesting U Other functions U Linguistic mapping U Expansions U Corrective feedback U
Group
Pre
Post
Z
Mean
Median
Range
Mean
Median
1 2 1 vs. 2
15.0 19.4
15.0 20.0 40.00*
3.0–25.0 10.0–27.0
26.8 10.9
27.00 14.0 40.0*
6.0–53.0 5.0–16.0
3.25** .63
1 2 1 vs. 2
41.1 33.9
38.0 32.0 54.00
26.0–77.0 18.0–58.0
31.8 41.9 49.50
34.00 43.0
6.0–53.0 18.0–61.0
2.79** 1.78
1 2 1 vs. 2
20.5 15.0
20.0 17.0 44.00
5.0–37.0 8.0–24.0
22.1 17.6
23.00 16.0 50.50
11.0–36.0 7.0–31.0
.73 1.25
1 2 1 vs. 2
20.9 25.4
19.0 27.0 59.50
.0–35.0 9.0–39.0
18.8 20.3
19.00 19.0 66.00
7.0–58.0 1.0–35.0
1.04 .98
1 2 1 vs. 2
2.5 5.0
2.0 2.0 58.50
.0–6.0 .0–15.0
2.7 3.1
3.00 2.0 71.50
.0–8.0 .0–8.0
.42 1.41
1 2 1 vs. 2
33.8 46.7
30.0 50.0 54.50
8.0–85.0 .0–80.0
29.3 30.3
31.00 41.0 67.00
.0–61.0 .0–54.0
.88 1.60
1 2 1 vs. 2
.8 .8
.0 .0 73.00
.0–5.0 .0–7.0
2.1 .7
.00 .0 58.50
.0–10.0 .0–4.0
2.39* .00
1 2 1 vs. 2
4.2 1.6
.0 .0 76.50
.0–28.0 .0–5.0
14.00 1.0 31.50*
.0–49.0 .0–20.0
3.52** 1.37
Note: Group 1 = intervention study group; group 2 = control group (no intervention). * Statistical significance, p < .05. ** p < .01.
16.3 5.2
Range
Pre vs. post
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Table 8 Group comparisons of difference in maternal measures for pre- and post-assessment. Measurement
Group
Intervention Mean
# of total utterances # of total words used # of different words MLU Communication functions Responding Non-contingent Asking/requesting Suggesting Other functions Linguistic mapping Expansions Corrective feedback **
Control SD
Mean
U SD
16.47 54.58 65.76 .17
96.85 230.77 159.47 .57
57.00 80.89 78.78 .33
71.64 286.00 154.12 .40
51.50 48.00 14.50** 60.50
11.71 9.29 1.53 2.12 .18 4.47 1.35 12.12
10.62 10.90 8.81 10.26 2.13 24.14 2.18 9.51
3.56 8.00 2.56 5.11 1.89 16.33 .11 3.67
10.89 13.53 8.89 12.17 3.91 29.39 2.93 7.50
26.00** 24.00** 72.50 70.50 52.00 63.50 57.00 31.50**
p < .01.
4. Discussion 4.1. Effect of intervention on children’s language-speech performance The findings of the present study suggest that parentimplemented intervention has a positive effect on children’s language and speech performance. Children in the intervention group showed significant improvement in all language measurements based on the analysis of their spontaneous speech and standardized testing following the intervention. The analysis of the post-assessment also suggested that children in the intervention group communicated using more intelligible speech and smaller gestures. These children also demonstrated a significant increase in the number of true consonants following the intervention, which indicated that the parent-implemented intervention was effective in speech development among children with CP but not children with CP who did not receive the intervention. Children in the control group did not show significant improvements in the monitored aspects of language and speech production except for expressive language age on the SELSI. Given the time (i.e., 3 months) between the initial and final assessments, increased expressive language age was unlikely to be meaningful. Although the difference in expressive language age prior to and following the intervention reached statistical significance, the difference in the mean ages was less than 3 months, which was shorter than the actual study period. Conversely, children with CP who received the intervention showed approximately a 5.7-month difference in language age between pre- and post-intervention assessments. Children in the intervention group showed a significantly greater extent of change between pre- and post-assessment in vocabulary size on the KM-BCDI, number of total utterances, and MLU in their spontaneous speech compared to those in the control group. No group differences emerged for any measurement at the initial assessment administered prior to the intervention. However, after the parent-implemented intervention program, children in the intervention group demonstrated significantly greater vocabulary size on the KM-BCDI and a greater number of true consonants than did those in the control group. Therefore, this study provides considerable empirical evidence of the benefit of a parentimplemented intervention program to facilitate language performance and to promote phonological development in young children with CP. Scherer and colleagues reported that the most significant result of their parent-implemented intervention is the reduction of glottal stops in young children with cleft lip and palate [20]. However, the effect of an intervention on the reduction of compensatory articulation errors in the present study was not
significant; instead, individual differences were manifested. In the intervention group, five of the eight children who showed compensatory articulation errors prior to the program demonstrated a reduction of these errors following the program. Two of the three children who exhibited an increase in compensatory articulation errors following the program also demonstrated marked increases in expressive language and, simultaneously, showed a higher use of compensatory articulation patterns. Parents obtained information on compensatory articulation errors during the parent training and listened to audio samples that demonstrated the articulatory patterns to prevent them from reinforcing inappropriately their child’s compensatory articulation error. Additionally, parents were instructed to model anterior speech sounds by ‘‘exaggerating lip movements’’. Given the result of compensatory articulation, it is unclear whether parents’ awareness of compensatory articulation errors and the simple technique of modeling of anterior speech sounds in this study were effective in eliminating compensatory articulation. Several factors are likely associated with different responses to the parentimplemented intervention in the production of compensatory articulation errors. That is, children with CP might demonstrate different responses depending on their velopharyngeal functions, appropriateness of their mothers’ stimulation skills or corrective feedback, and the frequency and intensity of the stimulation. Future studies on a parent-implemented intervention for children with CP should address this issue. 4.2. Changes in maternal measures following the intervention This study investigated changes in mothers’ use of language following an intervention to examine whether they can be trained to deliver language-stimulation skills and communication strategies. Regarding mothers’ language content and form, significant changes following the intervention were observed only for the number of different words. Mothers who received the training used significantly less number of different words following the intervention. This significant change is associated with the communication strategy of ‘‘repeat words’’ emphasized in the parent training. The intervention program encouraged mothers to model words repeatedly in accordance with their children’s interests and attention. As the mothers in the intervention group did not use a significantly different number of total utterances and words in the language samples collected from the pre- and postassessments, the post-assessment result could indicate that they repeatedly modeled identical words within the same number of utterances. Consequently, the language samples indicated that they used fewer number of different words over a period of 30 min.
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The training effects in this study were more pronounced in the maternal measures used for communication functions. The intervention program emphasized the importance of mothers’ responsiveness to their children’s utterances through the communication strategies of ‘‘wait for child’s response;’’ ‘‘listen to child’s speech;’’ ‘‘respond to child’s speech immediately;’’ and ‘‘provide immediate and appropriate verbal feedback, including modeling or expansion of child’s speech but not compensatory articulation.’’ Mothers who received the training showed a significant increase in the use of responding and a decrease in the use of non-contingent utterances. The intervention also differentiated responding from non-contingent utterances, which indicated that mothers’ inefficient verbal expressions were unrelated to their children’s interests and communicative attempts during interactions. Further, the intervention encouraged mothers to utilize a languagefacilitation method to show contingent and immediate responses to their children’s communication. Among the subtypes of responding, the percentages of expansion and corrective feedback increased following the intervention, which supports the finding that mothers can learn to use communication strategies efficiently to ‘‘respond to child’s speech immediately’’ and ‘‘provide immediate and appropriate verbal feedback.’’ In contrast, mothers who did not receive the training showed no positive changes; instead, they displayed a decrease in their use of responding and an increase in their use of non-contingent utterances 3 months later. The literature documents the supporting role of mothers’ linguistic responsiveness to accelerate children’s language development [27–30]. Given the language and speech improvement of children with CP who received the intervention, the present study also supports the benefit of mothers’ linguistic responsiveness to facilitate language and speech development in children with CP. 4.3. Limitations and future areas of research As any study, this investigation had some limitations. Even though efforts were made to compensate for the limited extent of parent training by communicating with mothers via email and telephone and by using a checklist of communication strategies, this parent training was conducted only one time because of regional distances and limited facilities. More systematic parenttraining sessions would be more beneficial, although the current findings support the point that even a parent training with limited clinician instruction can change mothers’ use of communication strategies and children’s speech-language performance. Another limitation of this study is that only few children with CP who did not receive the intervention were included in the study. The children in the control group were also slightly younger compared to the children in the intervention, even though the two groups did not significantly differ in age. Further investigations using larger age-matched control groups are needed. Additionally, follow-up measures were not available after the 3-month intervention to examine maintenance effects. Future study should also examine the maintenance effects of a parentedimplemented intervention on speech and language performance of children with CP. Other important future research directions include performing an analysis of factors related to maximum gains of intervention, such as timing of the intervention and frequency and intensity of parent training. 5. Conclusion This study provides considerable data-based evidence on the benefit of a parent-implemented intervention program to facilitate language and speech development in young children with CP. The results of the study suggest that mothers can be trained to deliver language-stimulation skills and communication strategies. Given
the positive changes in children with CP and their mothers, the present investigation demonstrated the benefits of a parentimplemented intervention in young children with CP despite the very short duration of the intervention period and the limited extent of parent training. This study has important implication for regions of the world where few specialized services are available for young children with CP, such as fully qualified speech-language pathologists and related professionals. Acknowledgments We thank all children and their parents for participating in this study and we thank Heewon Mon, Minyoung Kim, and Haerim Sim for their assistance in collecting and analyzing the data. This work was supported by the National Research Foundation of Korea (NRF2010-332-B00401).
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Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Effectiveness of a parent-implemented intervention program for young children with cleft palate§ Seunghee Ha * Division of Speech Pathology and Audiology, Audiology and Speech Pathology Research Institute, Hallym University, Republic of Korea
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 January 2015 Received in revised form 18 February 2015 Accepted 19 February 2015 Available online 26 February 2015
Objective: This study investigated the effectiveness of a parent-implemented intervention on children’s speech-language development and parents’ interaction styles. Methods: Seventeen children with cleft palate (CP) and their mothers participated in all sessions of a parent-implemented intervention program. Nine children with CP and their mothers who did not receive the intervention were included to examine the full effectiveness of the program. The intervention program consisted of four phases, pre-intervention test, parent training, parent-implemented intervention at children’s home for 3 months, and post-intervention test. Children’s language and speech measures and maternal measures from pre- and post-intervention tests were compared between groups (intervention vs. no intervention). Results: Children who received a parent-implemented intervention exhibited significant improvement in language measures based on standardized tests and quantitative language and speech measures from spontaneous utterances. The children in the intervention group showed a significantly greater extent of change in expressive vocabulary size, number of total words, and mean length of utterance than did those who did not receive the intervention. Mothers who received the training showed a significantly decreased number of different words, increased responsiveness, and decreased non-contingent utterances for children’s communication acts compared to those who did not receive the training. Conclusions: The results of the study support the effectiveness of parent-implemented early intervention on positive changes in children’s speech-language development and mothers’ use of communication strategies. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Children with cleft palate Parent-implemented intervention Speech-language development Babies–mothers interaction Speech therapy Compensatory speech errors
1. Introduction A number of studies over the past 20 years have shown that children with cleft palate (CP) demonstrate a variety of speechlanguage impairments [1–16]. Deficits in the onset and composition of their babbling emerge during the prelinguistic period [1–3]. The literature also reports that the deficits in early vocalization in children with CP have cascading effects on their subsequent speech and lexical development [4–6]. The restricted diversities of
§ This study was conducted as an extend study of Ha (2013) published at Korean Journal of Speech-Language and Hearing Disorders and part of the study was presented at the 71st Annual Meeting of the American Cleft Palate-Craniofacial Association, Indianapolis, Indiana, March, 2014. * Correspondence to: Division of Speech pathology and Audiology, Audiology and Speech Pathology Research Institute, Hallym University, Life Science Hall # 8606, 39 Hallymdaehak-gil, Chuncheon-si, Kangwon-do, Republic of Korea. Tel.: +82 332482215. E-mail address: [email protected]
http://dx.doi.org/10.1016/j.ijporl.2015.02.023 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
sounds and phonetic structures of early vocalization result in late onset of first words, limited lexical development and consonant inventories, and the emergence of compensatory articulation errors. A substantial number of children with CP are reported to have persistent speech-language problems during the preschool period [16]. Studies describing deficits of early vocalization and later speech-language development in children with CP highlight the need to develop and provide early intervention programs for this population. Effective early intervention for children with CP reduces language and speech problems and the need for more intensive clinician-implemented intervention. The literature supports the efficacy of early intervention programs on improving expressive language and speech performance in young children with CP [17–22]. Efficacy of early intervention has led clinicians and researchers to develop various early intervention programs and service-delivery models for children with CP. Research also suggests that parental involvement is an essential component of effective early intervention programs for young children prior to 3 years of age. On a practical level, it
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appears difficult to provide infants and toddlers with direct and clinician-implemented therapy because it demands attention and cooperation from the children. Such therapy could obtain maximum gains if well-trained parents deliver intervention skills in natural environments following the levels and durations of children’s attention and interest. Many studies on early language intervention have demonstrated that parents can be trained to use language stimulation skills, including modeling and appropriate responses during daily life interactions [17–20]. These parentimplemented intervention programs lead to an expansion of children’s vocabulary and speech sound inventories. Pamplona and Ysunza supported the concept that active participation of mothers during speech therapy yields better therapy outcomes for language skills than do clinician-implemented speech therapy given to 3–4year olds with CP [19]. Scherer and colleagues explored the effectiveness of a parentimplemented, focused stimulation program on the speech characteristics of children younger than 3 years with cleft lip and palate [20]. Mothers were trained to deliver the intervention reliably, which yielded positive changes in language and speech performance in children with cleft lip and palate. In particular, the researchers found increased sound inventories, increased speech accuracy, and decreased use of glottal stops as the main outcomes of the intervention. Although the researchers included a comparison for typically developing children without CP at the same language development level, their study did not provide a prospective comparison between children with CP who did and did not receive the intervention over the same time interval. Therefore, it is necessary to conduct further studies to provide empirical evidence to validate a parent-implemented intervention program. Such study should include a control group to exclude the possible ongoing results of natural maturation and growth. The purpose of this study was to investigate the effectiveness of a parent-implemented intervention program for young children with CP. The effectiveness of this intervention program was determined based on changes in speech-language performance of children with CP and mothers’ use of communication strategies compared to children with CP and mothers who did not receive the parent training. 2. Methods 2.1. Participants Seventeen children with non-syndromic CP and their mothers participated in all study sessions, including parent training, parent-implemented intervention in the children’s homes over a 3-month period, and pre- and post-assessment procedures. Originally, 22 children with CP and their mothers received the initial assessment and parent training. However, 4 mothers could not complete the parent-implemented intervention and withdrew from the study. Another child was diagnosed with velocardiofacial syndrome following the intervention program; therefore, the data from this participant were excluded from this study. Nine children with non-syndromic CP and their mothers were included as a control group that received no intervention to compare the effects of the program against the course of natural development in children with CP over the same period. The mother–child pairs in the control group attended only two assessment sessions administered within a 3-month interval. No child with CP in either group had significant medical or neurological impairments or genetic syndromes, as evidenced in the medical history form. According to parents’ report, each child had history of otitis media and received ear tubes at the time of primary palate repair. Table 1 shows the children’s genders, ages at the time of the initial assessment, cleft type, and age at palatal
surgery. The data also included mothers’ ages and years of public education for both the intervention and control groups. The intervention group included 10 girls and 7 boys, ranging in age from 13 to 29 months (mean = 19.5 months) at the time of the study initiation. The control group included 5 girls and 4 boys, ranging in age from 13 to 23 months (mean = 16.4) at the time of study initiation. A t-test comparison showed no significant differences in children’s ages between groups (t = 1.797, df = 24, p = .085). Mothers in the intervention group ranged in age from 26 to 41 years, and the mothers in the control group ranged in age from 28 to 40 years. All mothers had completed education beyond high school. No child had previously enrolled in any speechlanguage intervention. However, mothers reported receiving information about the effects of clefting on speech and language development through local craniofacial clinics. Mothers also received information on simple interaction skills to stimulate speech and language development in their children. A formal Institutional Review Board at the researcher’s university was not available when the present study was initiated. However, the principles outlined in the Declaration of Helsinki were followed, and signed consent forms were obtained from all the children’s parents before collecting the data. All children and their parents participated in the study voluntarily, and they were allowed to withdraw from the study if they chose. 2.2. Assessment procedures All mother–child pairs participated in two assessments conducted at 3-month interval. Standardized tests and two 20min video and audiotaped language samples obtained in participants’ homes provided the data. The two 20-min language samples involved mother–child and evaluator–child interactions, respectively. The standardized tests included (1) a Sequenced Language Scale for Infants (SELSI) [23] to provide a receptive and expressive language age score and (2) Korean MacArthur-Bates Communicative Development Inventories (KM-BCDI) [24]. The language samples were collected while children interacted with their mothers and an evaluator during free play with toys and bookreading activities. The same toys and books were used during the pre- and post-assessment sessions. Two graduate students majoring in speech pathology and trained for this study were involved as evaluators. Mothers were instructed to play with their babies as they typically interacted in their homes. The language sample that included evaluator–child interaction was collected following the mother–child interaction. 2.3. Child production measures From the middle of the two 20-min language samples from evaluator–child and mother–child interactions, we selected two 15-min segments, and the resulting 30-min language samples from each participant were included in the analysis. Several trained graduate and undergraduate students in a speech pathology program transcribed and analyzed the language samples. The transcribers and analyzers were blinded to the purpose of the study and its sampling conditions (e.g., treatment phase). Undergraduate students first performed orthographic transcriptions of each language sample. The researcher and two graduate students who collected the data examined the accuracy of the transcriptions. Two graduate students performed phonetic transcriptions of children’s language samples. If disagreement occurred between the two transcribers, the researcher and two graduate students listened to and examined the parts together to determine the final transcription for the data analysis. The children’s measures included (1) language age score for SELSI [22], (2) number of expressive vocabulary from the
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Table 1 Participant characteristics for the children with cleft palate and their mothers in both groups. Group
No.
Child Gender
Age (months)
Cleft type
Age at palate repair (months)
Age (years)
Years of education
Intervention
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
F F F F F F F F F F M M M M M M M
18 13 29 22 25 18 13 20 21 18 15 22 27 17 16 19 18 19.5
UCLP CP CP CP UCLP CP UCLP UCLP CP UCLP UCLP UCLP BCLP UCLP UCLP UCLP UCLP
12 12 18 11 18 13 12 13 11 11 11 12 12 11 11 11 11 12.4
35 31 31 35 35 33 33 34 36 31 35 29 32 36 41 28 41 33.3
16 12 16 16 12 16 16 16 12 16 16 12 14 14 16 16 16
1 2 3 4 5 6 7 8 9
F F F F F M M M M
23 13 18 19 15 15 15 16 15 16.4
CP CP CP UCLP CP UCLP UCLP UCLP BCLP
16 10 12 10 12 11 11 11 13 11.6
33 40 35 30 31 30 41 28 46 34.9
12 12 18 16 16 14 16 16 12
Mean Control
Mean
Mother
Note: UCLP = unilateral cleft lip and palate; BCLP = bilateral cleft lip and palate; CP = cleft palate; F = female; M = male.
administration of KM-BCDI [23], (3) percentage of each communication mode for gesture, vocalization, and intelligible speech, (4) total number of words, (5) number of different words, (6) mean length of utterances (MLU), (7) number of true consonants, and (8) percentage of compensatory misarticulations. In terms of measures of communication mode, intelligible speech indicated that children’s utterances were phonetically similar or identical to the adult target in terms of syllable shape and segmental patterning; therefore, they were linked systematically with the contexts. True consonants included all consonant sounds, except glottal stops and glides, based on Stoel–Gammon’s definition [25]. 2.4. Parent language measures The maternal measures were related to the length and complexity of utterances using quantitative measures and communication functions. The maternal quantitative measures included (1) total number of utterances, (2) total number of words used, (3) number of different words, and (4) the MLU. A list of communication functions was modified and defined using the communication strategies and types suggested in previous studies [26–28]. The communication functions included five categories, (1) responding, (2) non-contingent utterances, (3) requesting and asking, (4) suggesting, and (5) other functions (e.g., calling, attention getter, or prohibiting). Responding was analyzed in detail to classify the subtypes as the communication function, which has been reported to have positive effect on children’s language development in the literature [27–30]. The subtypes of responding included linguistic mapping, correcting children’s unintelligible speech (corrective feedback), and expansions. Non-contingent utterances involved mothers’ verbal comments on behaviors or objects far from their children’s attention and interest during the interactions. These functions were considered less effective on children’s language development; therefore, they were separated from responsiveness. The
pre- and post-intervention test sessions were compared on the percentage of each category of communication function in the mothers’ language samples. 2.5. Parent-implemented intervention The intervention program consisted of parent training and parent-implemented intervention at home during a 3-month period. Parents in the intervention group participated in individualized or small group training conducted one week after the initial assessment. The content and procedures of the parental training were developed based on a careful review of previous studies [26– 34] on early interventions for various populations, including children with CP. Parent training consisted of a description of language-speech characteristics of children with CP, listening to audio samples of speech problems (i.e., hypernasality and compensatory articulation errors) caused by CP and velopharyngeal dysfunction, and instruction of language stimulation skills and communication strategies. In particular, the researcher selected 11 communication strategies for the training, and parents could easily follow these strategies at home. The communication strategies included (1) face-to-face parent-child communication, (2) following a child’s interests, (3) emphasizing the initial oral sound of words, (4) exaggerating lip movements, (5) speaking slowly, (6) repeating words, (7) using short and simple expressions, (8) waiting for the child’s response, (9) listening to the child’s speech, (10) responding to the child’s speech immediately, and (11) providing immediate and appropriate verbal feedback that included modeling or expanding on the child’s speech except for compensatory articulation. Using these communication strategies, mothers were taught to create episodes of joint attention and action to generate child-oriented responses and to optimize linguistic responsiveness. These strategies addressed the child’s interests and delivered communicative attempts to stimulate language development.
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Table 2 Comparison of language performance for children in the intervention and control groups. Measurement
Group
Mean
Median
Range
Mean
Median
Range
SELSI-EA (months)
1 2 1 vs. 2
13.9 13.1
13 13 70.00
5–22 7–18
19.2 15.4
19 14 44.00
12–29 10–24
1 2 1 vs. 2
16.1 8.2
6 5 72.00
0–110 0–27
79.4 21.2
46 8 27.00**
7–249 0–109
3.52** 1.61
1 2 1 vs. 2
25.9 30.2
11 14 58.50
0–150 1–112
65.6 43.1
34 40 70.00
1–235 0–131
2.49* 1.19
1 2 1 vs. 2
23.5 15.1
10 6 75.50
0–167 0–54
61.9 14.4
29 20 44.00
0–294 0–31
2.47* .00
1 2 1 vs. 2
5.0 3.2
2 2 72.50
0–32 0–14
12.3 5.1
4 5 64.50
0–60 0–15
2.99** 1.85
1 2 1 vs. 2
0.79 0.91
1.00 1.00 63.00
.0–1.20 .0–1.07
1.00 1.00 49.00
1.0–1.33 .0–1.07
2.50* 0.96
U Vocabulary size on KMBCDI U # of total utterances U # of total words U # of different words U MLU U
Pre
Post
1.07 0.79
Z Pre vs. Post 3.64** 2.71**
Note: Group 1 = intervention study group; group 2 = control group (no intervention). SELSI-EA = expressive language age score in months on the SELSI; MLU = mean length of utterance. * Statistical significance, p < .05. ** p < .01.
The program also considered the speech characteristics of children with CP (i.e., preferring posterior sounds) and taught mothers to model oral anterior sounds by exaggerating lip movements. Language stimulation skills and communication strategies were introduced in detail using 4 video clips created in the researcher’s lab. The average duration of video clips, which demonstrated target skills and strategies, was 5 min. Mothers also received individualized coaching based on their videotaped interactions during the pre-assessment. The training session lasted approximately 3–4 h and included educational video clips. Mothers in the intervention group delivered a parent-implemented intervention program in their homes after the parent training over a 3-month period. A checklist of the communication strategies was created and given to mothers. Mothers were asked to indicate how long they worked with their child each day and whether they considered and used the communication strategies when interacting with their children. All mothers in the intervention group were monitored and coached biweekly over the 3 months via telephone and they were also encouraged to send video clips of their interactions with their children once a month so they could receive regular and specific instruction and further coaching.
3. Results 3.1. Children’s measures Tables 2–5 show the language and speech performances of children with CP in the two groups prior to and following the intervention program. The results indicated that children in the intervention group showed significant increases in expressive language age (Z = 3.64, p < .01) on the SELSI and number of expressive vocabulary (Z = 3.52, p < .01) on the KM-BCDI. In addition to the results based on the administration of standardized tests, certain language and speech outcomes based on the analysis of spontaneous speech samples showed positive changes following the intervention program. Children in the intervention group showed significant improvement in the number of total utterances (Z = 2.49, p < .05), number of total words (Z = 2.47, p < .05), number of different words (Z = 2.99, p < .01), and MLU (Z = 2.50, p < .05) following the intervention. Regarding communication modes, children in the intervention group used fewer gestures (Z = 2.84, p < .01) and more intelligible speech (Z = 2.65, p < .01) following the intervention. In
Table 3 Comparison of the communication mode percentages for children in the two groups. Measurement
% Gesture U % Vocalization U % Intelligible speech U
Group
Pre
Post
Z
Mean
Median
Range
Mean
Median
1 2 1 vs. 2
45.1 47.0
42 59 73.00
19–85 10–78
28.0 38.0
27 40 51.00
2–68 2–66
1 2 1 vs. 2
43.2 47.0
41 35 63.50
15–75 10–78
46.0 43.3
45 47 72.50
5–93 18–66
1 2 1 vs. 2
11.8 11.4
6 8 71.00
0–50 0–39
25.9 18.7
16 12 60.00
1–67 0–80
Note: Group 1 = intervention study group; group 2 = control group (no intervention). ** p < .01.
Range
Pre vs. post 2.84** .77
.40 .06 2.65** .53
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Table 4 Comparison of speech performance for children in the two groups. Measurement
Group
Pre Median
Range
Mean
# of true consonants
1 2 1 vs. 2
5.1 3.6
4 2 62.50
0–16 2–9
8.5 4.4
1 2 1 vs. 2
14.4 3.56
25.0 0 58.00
0–72 0–19.3
Mean
U % Compensatory misarticulations U
Post
Z
13.1 7.6
Median
Range
6.5 3 39.00*
1–18 1–12
23.6 0 69.50
0–61 0–33.3
Pre vs. post 3.38** 1.38
.42 .67
Note: Group 1 = intervention study group; group 2 = control group (no intervention). * Statistical significance, p < .05. ** p < .01. Table 5 Group comparison of the difference in children’s measures between pre- and post-assessments. Measurement
Group
Intervention
SELSI-EA (months) Vocabulary size on KMBCDI # of total utterances # of total words # of different words MLU # of true consonants % compensatory misarticulations Communication mode % Gesture % Vocalization % Intelligible speech
Control
U
SD
Mean
SD
4.52 63.29 39.65 38.35 7.29 .28 3.35 1.25
1.74 60.01 64.47 64.88 10.49 .43 3.06 17.50
3.22 13.00 12.89 .67 1.89 .12 .89 4.07
1.64 26.93 25.70 13.81 2.67 .60 1.83 14.63
45.00 23.00** 57.50 35.00* 59.50 34.00* 42.00 65.00
17.06 2.76 14.18
21.77 31.39 19.50
9.0 1.78 7.22
27.74 23.82 16.76
60.00 75.00 55.00
Mean
Note: SELSI-EA = expressive language age score in months on the SELSI; MLU = mean length of utterance. * Statistical significance, p < .05. ** p < .01.
addition, children in the intervention group exhibited significant increases in the number of true consonants (Z = 3.38, p < .01). On the other hand, children who did not receive the parentimplemented intervention showed a significant increase in only expressive language age (Z = 2.71, p < .01) on the SELSI 3 months later. Further, the children in the control group exhibited no significant changes in other language and speech measures over the same period. The statistical comparison of the two groups showed no significant differences on all measures of language and speech performance at the initial assessment. Following the intervention, the intervention group showed a significantly greater number of expressive vocabulary on the KM-BCDI (U = 27.00, p < .01) and greater number of true consonants (U = 39.00, p < .05) compared to the control group. The means and standard deviations of delta values between the measures of the pre- and post-assessments for each child in the two groups were calculated to determine whether children in the intervention group showed significantly greater change after the intervention program compared to children in the control group (see Table 5). Children in the intervention group made significant improvements on measures of vocabulary size on the KM-BCDI (U = 23.00, p < .01), number of total words (U = 35.00, p < .05), and MLU (U = 34.00, p < .05) compared to those in the control group. Although group differences did not reach statistical significance, children in the intervention group demonstrated greater increases in the use of intelligible speech and number of true consonants compared to the control group. The intervention group also showed a decrease in the percentage of compensatory misarticulation following the intervention, whereas the control group showed an increase in the percentage of compensatory misarticulation.
3.2. Maternal measures Changes in mothers’ use of language were determined and used to investigate the effectiveness of the parent-implemented intervention for young children with CP. Table 6 shows the results associated with mothers’ forms and content of language in the two groups at the initial and final assessments administered 3 months apart. Except for the number of different words, changes in mothers’ uses of language over time were not obvious in either group. Mothers in the intervention group used significantly fewer number of different words with their children after the intervention (Z = 2.64, p < .01). In contrast, mothers in the control group used significantly more words (Z = 2.19, p < .05) with their children at the final assessment. Table 7 displays the percentages of all communication functions for mothers in the two groups at the pre- and postassessments. A comparison of pre- and post-measures indicated that mothers in the intervention group significantly increased the percentage of responding (Z = 3.25, p < .01) and decreased the use of non-contingent utterances (Z = 2.79, p < .01). Among the subtypes of responding function, mothers in the intervention group used more expansions (Z = 2.39, p < .05) and corrective feedback (Z = 3.52, p < .01). However, mothers who did not receive the training showed no changes in communication functions over the two assessments. The statistical comparison of the two groups showed that mothers in the intervention group used significantly more words (U = 36.50, p < .05) and a significantly lower percentage of responding (U = 40.00, p < .05) compared to mothers in the control group at the pre-assessment. On the other hand, mothers in the intervention group used fewer different words (U = 38.00, p < .05), had greater MLU (U = 32.50, p < .05), a higher percentage of
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Table 6 Group comparison of measures on mothers’ utterances prior to and following the intervention period. Measurement
Group
Mean
Median
Range
Mean
Median
Range
# of total utterances
1 2 1 vs. 2
232.82 190.11
222 176 42.00
125–426 98–449
249.29 247.11
228 222 75.50
144–457 177–384
0.45 1.96
1 2 1 vs. 2
724.00 529.67
701 459 36.50*
426–1299 309–1069
669.41 610.56
629 557 60.50
437–1135 442–845
0.54 1.01
1 2 1 vs. 2
211.18 141.89
160 139 42.00
106–808 87–192
145.41 220.67
145 177 38.00*
109–205 106–622
2.64** 2.19*
1 2 1 vs. 2
2.88 2.74
2.74 2.56 62.00
2.18–4.06 1.93–4.04
2.71 2.40
2.62 2.40 32.50*
2.22–3.44 2.01–3.25
1.28 1.72
U # of total words used U # of different words U MLU U
Pre
Post
Z Pre vs. post
Note: Group 1 = intervention study group; group 2 = control group (no intervention). * Statistical significance, p < .05. ** p < .01.
mothers in the intervention group used significantly less different words following the intervention program while mothers in the control group used an increased number of different words 3 months later. In terms of mothers’ use of communication functions, following the intervention program, the two groups differed significantly in responding (U = 26.60, p < .01), noncontingent utterances (U = 24.00, p < .01), and corrective feedback (U = 31.50, p < .01). Mothers in the intervention group showed an increased use of responding and corrective feedback, whereas they showed a decreased use of non-contingent utterances. In contrast, mothers in the control group showed a decreased use of responding and an increased use of non-contingent utterances.
responding (U = 40.00, p < .05), and corrective feedback (U = 31.50, p < .05) compared to mothers in the control group at the postassessment. Table 8 shows the means and standard deviations of delta values for all maternal measures, which included differences between the pre- and post-assessments measures for all mothers in both groups. Mann–Whitney U tests were conducted to determine whether mothers in the intervention group changed significantly more compared to the control group following the intervention. This statistical analysis revealed that following the intervention program, the two groups differed significantly in number of different words (U = 14.50, p < .01). Specifically,
Table 7 Group comparisons for mothers’ communication function prior to and following the intervention period. Measurement (%)
Responding U Non-contingent U Asking/requesting U Suggesting U Other functions U Linguistic mapping U Expansions U Corrective feedback U
Group
Pre
Post
Z
Mean
Median
Range
Mean
Median
1 2 1 vs. 2
15.0 19.4
15.0 20.0 40.00*
3.0–25.0 10.0–27.0
26.8 10.9
27.00 14.0 40.0*
6.0–53.0 5.0–16.0
3.25** .63
1 2 1 vs. 2
41.1 33.9
38.0 32.0 54.00
26.0–77.0 18.0–58.0
31.8 41.9 49.50
34.00 43.0
6.0–53.0 18.0–61.0
2.79** 1.78
1 2 1 vs. 2
20.5 15.0
20.0 17.0 44.00
5.0–37.0 8.0–24.0
22.1 17.6
23.00 16.0 50.50
11.0–36.0 7.0–31.0
.73 1.25
1 2 1 vs. 2
20.9 25.4
19.0 27.0 59.50
.0–35.0 9.0–39.0
18.8 20.3
19.00 19.0 66.00
7.0–58.0 1.0–35.0
1.04 .98
1 2 1 vs. 2
2.5 5.0
2.0 2.0 58.50
.0–6.0 .0–15.0
2.7 3.1
3.00 2.0 71.50
.0–8.0 .0–8.0
.42 1.41
1 2 1 vs. 2
33.8 46.7
30.0 50.0 54.50
8.0–85.0 .0–80.0
29.3 30.3
31.00 41.0 67.00
.0–61.0 .0–54.0
.88 1.60
1 2 1 vs. 2
.8 .8
.0 .0 73.00
.0–5.0 .0–7.0
2.1 .7
.00 .0 58.50
.0–10.0 .0–4.0
2.39* .00
1 2 1 vs. 2
4.2 1.6
.0 .0 76.50
.0–28.0 .0–5.0
14.00 1.0 31.50*
.0–49.0 .0–20.0
3.52** 1.37
Note: Group 1 = intervention study group; group 2 = control group (no intervention). * Statistical significance, p < .05. ** p < .01.
16.3 5.2
Range
Pre vs. post
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Table 8 Group comparisons of difference in maternal measures for pre- and post-assessment. Measurement
Group
Intervention Mean
# of total utterances # of total words used # of different words MLU Communication functions Responding Non-contingent Asking/requesting Suggesting Other functions Linguistic mapping Expansions Corrective feedback **
Control SD
Mean
U SD
16.47 54.58 65.76 .17
96.85 230.77 159.47 .57
57.00 80.89 78.78 .33
71.64 286.00 154.12 .40
51.50 48.00 14.50** 60.50
11.71 9.29 1.53 2.12 .18 4.47 1.35 12.12
10.62 10.90 8.81 10.26 2.13 24.14 2.18 9.51
3.56 8.00 2.56 5.11 1.89 16.33 .11 3.67
10.89 13.53 8.89 12.17 3.91 29.39 2.93 7.50
26.00** 24.00** 72.50 70.50 52.00 63.50 57.00 31.50**
p < .01.
4. Discussion 4.1. Effect of intervention on children’s language-speech performance The findings of the present study suggest that parentimplemented intervention has a positive effect on children’s language and speech performance. Children in the intervention group showed significant improvement in all language measurements based on the analysis of their spontaneous speech and standardized testing following the intervention. The analysis of the post-assessment also suggested that children in the intervention group communicated using more intelligible speech and smaller gestures. These children also demonstrated a significant increase in the number of true consonants following the intervention, which indicated that the parent-implemented intervention was effective in speech development among children with CP but not children with CP who did not receive the intervention. Children in the control group did not show significant improvements in the monitored aspects of language and speech production except for expressive language age on the SELSI. Given the time (i.e., 3 months) between the initial and final assessments, increased expressive language age was unlikely to be meaningful. Although the difference in expressive language age prior to and following the intervention reached statistical significance, the difference in the mean ages was less than 3 months, which was shorter than the actual study period. Conversely, children with CP who received the intervention showed approximately a 5.7-month difference in language age between pre- and post-intervention assessments. Children in the intervention group showed a significantly greater extent of change between pre- and post-assessment in vocabulary size on the KM-BCDI, number of total utterances, and MLU in their spontaneous speech compared to those in the control group. No group differences emerged for any measurement at the initial assessment administered prior to the intervention. However, after the parent-implemented intervention program, children in the intervention group demonstrated significantly greater vocabulary size on the KM-BCDI and a greater number of true consonants than did those in the control group. Therefore, this study provides considerable empirical evidence of the benefit of a parentimplemented intervention program to facilitate language performance and to promote phonological development in young children with CP. Scherer and colleagues reported that the most significant result of their parent-implemented intervention is the reduction of glottal stops in young children with cleft lip and palate [20]. However, the effect of an intervention on the reduction of compensatory articulation errors in the present study was not
significant; instead, individual differences were manifested. In the intervention group, five of the eight children who showed compensatory articulation errors prior to the program demonstrated a reduction of these errors following the program. Two of the three children who exhibited an increase in compensatory articulation errors following the program also demonstrated marked increases in expressive language and, simultaneously, showed a higher use of compensatory articulation patterns. Parents obtained information on compensatory articulation errors during the parent training and listened to audio samples that demonstrated the articulatory patterns to prevent them from reinforcing inappropriately their child’s compensatory articulation error. Additionally, parents were instructed to model anterior speech sounds by ‘‘exaggerating lip movements’’. Given the result of compensatory articulation, it is unclear whether parents’ awareness of compensatory articulation errors and the simple technique of modeling of anterior speech sounds in this study were effective in eliminating compensatory articulation. Several factors are likely associated with different responses to the parentimplemented intervention in the production of compensatory articulation errors. That is, children with CP might demonstrate different responses depending on their velopharyngeal functions, appropriateness of their mothers’ stimulation skills or corrective feedback, and the frequency and intensity of the stimulation. Future studies on a parent-implemented intervention for children with CP should address this issue. 4.2. Changes in maternal measures following the intervention This study investigated changes in mothers’ use of language following an intervention to examine whether they can be trained to deliver language-stimulation skills and communication strategies. Regarding mothers’ language content and form, significant changes following the intervention were observed only for the number of different words. Mothers who received the training used significantly less number of different words following the intervention. This significant change is associated with the communication strategy of ‘‘repeat words’’ emphasized in the parent training. The intervention program encouraged mothers to model words repeatedly in accordance with their children’s interests and attention. As the mothers in the intervention group did not use a significantly different number of total utterances and words in the language samples collected from the pre- and postassessments, the post-assessment result could indicate that they repeatedly modeled identical words within the same number of utterances. Consequently, the language samples indicated that they used fewer number of different words over a period of 30 min.
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The training effects in this study were more pronounced in the maternal measures used for communication functions. The intervention program emphasized the importance of mothers’ responsiveness to their children’s utterances through the communication strategies of ‘‘wait for child’s response;’’ ‘‘listen to child’s speech;’’ ‘‘respond to child’s speech immediately;’’ and ‘‘provide immediate and appropriate verbal feedback, including modeling or expansion of child’s speech but not compensatory articulation.’’ Mothers who received the training showed a significant increase in the use of responding and a decrease in the use of non-contingent utterances. The intervention also differentiated responding from non-contingent utterances, which indicated that mothers’ inefficient verbal expressions were unrelated to their children’s interests and communicative attempts during interactions. Further, the intervention encouraged mothers to utilize a languagefacilitation method to show contingent and immediate responses to their children’s communication. Among the subtypes of responding, the percentages of expansion and corrective feedback increased following the intervention, which supports the finding that mothers can learn to use communication strategies efficiently to ‘‘respond to child’s speech immediately’’ and ‘‘provide immediate and appropriate verbal feedback.’’ In contrast, mothers who did not receive the training showed no positive changes; instead, they displayed a decrease in their use of responding and an increase in their use of non-contingent utterances 3 months later. The literature documents the supporting role of mothers’ linguistic responsiveness to accelerate children’s language development [27–30]. Given the language and speech improvement of children with CP who received the intervention, the present study also supports the benefit of mothers’ linguistic responsiveness to facilitate language and speech development in children with CP. 4.3. Limitations and future areas of research As any study, this investigation had some limitations. Even though efforts were made to compensate for the limited extent of parent training by communicating with mothers via email and telephone and by using a checklist of communication strategies, this parent training was conducted only one time because of regional distances and limited facilities. More systematic parenttraining sessions would be more beneficial, although the current findings support the point that even a parent training with limited clinician instruction can change mothers’ use of communication strategies and children’s speech-language performance. Another limitation of this study is that only few children with CP who did not receive the intervention were included in the study. The children in the control group were also slightly younger compared to the children in the intervention, even though the two groups did not significantly differ in age. Further investigations using larger age-matched control groups are needed. Additionally, follow-up measures were not available after the 3-month intervention to examine maintenance effects. Future study should also examine the maintenance effects of a parentedimplemented intervention on speech and language performance of children with CP. Other important future research directions include performing an analysis of factors related to maximum gains of intervention, such as timing of the intervention and frequency and intensity of parent training. 5. Conclusion This study provides considerable data-based evidence on the benefit of a parent-implemented intervention program to facilitate language and speech development in young children with CP. The results of the study suggest that mothers can be trained to deliver language-stimulation skills and communication strategies. Given
the positive changes in children with CP and their mothers, the present investigation demonstrated the benefits of a parentimplemented intervention in young children with CP despite the very short duration of the intervention period and the limited extent of parent training. This study has important implication for regions of the world where few specialized services are available for young children with CP, such as fully qualified speech-language pathologists and related professionals. Acknowledgments We thank all children and their parents for participating in this study and we thank Heewon Mon, Minyoung Kim, and Haerim Sim for their assistance in collecting and analyzing the data. This work was supported by the National Research Foundation of Korea (NRF2010-332-B00401).
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