Research in Developmental Disabilities 30 (2009) 1221–1228
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Research in Developmental Disabilities
Cutoffs, norms, and patterns of comorbid difficulties in children with developmental disabilities on the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT-Part 2) Johnny L. Matson *, Jill C. Fodstad, Sara Mahan Louisiana State University, United States
A R T I C L E I N F O
A B S T R A C T
Article history: Received 18 March 2009 Accepted 21 April 2009
Behavioral symptoms of comorbid psychopathology of 651 children 17–37 months of age who were at risk for developmental disabilities were studied using the BISCUIT-Part 2. In Study 1, norms and cutoff scores were established for this new scale on this sample. In Study 2, frequency of response on the 52 items measured was reported. Problems in eating and sleep were the most common with just over15% of the sample experiencing these difficulties of either a moderate or severe nature. For severe problems, the most commonly reported difficulties were inattention/impulsivity, and tantrums/conduct behavior problems. Implications of this scale and these data for early identification of behavior disorders in atypically developing children are discussed. ß 2009 Elsevier Ltd. All rights reserved.
Keywords: BISCUIT Comorbidity Normative data Cutoffs Atypical development Impulsivity Tantrums
Developmental disabilities are a wide range of intellectual and physical delays and handicaps which interfere with typical development (Hsieh, 2008; Matson, Cooper, Malone, & Moskow, 2008; Matson, Kiely, & Bamburg, 1997; Mitchell & Hauser-Cram, 2008; Paclawskyj, Matson, Bamburg, & Baglio, 1997). These problems are pervasive and effect the development of independent living skills, socialization and psychosocial adjustment, as well as school performance. One of the primary reasons factors associated with these delays, which further compound and complicate normal development, are co-occurring problems such as social deficits, challenging behaviors, and psychopathology (Agaliotis & Kalyva, 2008; Myrbakk & von Tetzchner, 2008; Ringdahl, Call, Mews, Boelter, &
* Corresponding author at: Department of Psychology, LSU, Baton Rouge, LA 70803, United States. E-mail address:
[email protected] (J.L. Matson). 0891-4222/$ – see front matter ß 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.ridd.2009.04.004
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Christensen, 2008). These problems co-occur with each other at very high rates. Without proper diagnosis and treatment these difficulties tend to persist and intensify and they can have a lifetime course (Lifshitz, Merrick, & Morad, 2008; Matson, Smiroldo, & Bamburg, 1998). A major and important advance in the field of developmental disabilities has been early diagnosis and intervention (Eikeseth, 2009; Matson & Smith, 2008; Matson, Wilkins, & Gonzales, 2008). Efforts in this area have been based on the premises noted above, and on the opinion that the earlier these difficulties can be addressed, the better the long-term prognosis. Researchers are aware that the full spectrum of problem behaviors must be recognized and addressed (Matson, 2007b). However, to date most of the focus has been on identifying symptoms of a primary disorder without focusing on comorbid disorders. These co-occurring problems can be very important for prognosis, and clearly warrant targeting for intervention. However, the development of tools to assist in these assessments has received little attention, particularly with very young children. The purpose of this paper was to describe psychometric properties of the BISCUIT-Part 2, which was designed specifically for the purpose of screening for co-occurring disorders. Additionally, we addressed the rate at which these comorbid conditions were present in this very young at risk population. 1. Methods 1.1. Participants The sample consisted of 651 children between the ages of 17 and 37 months (M = 26.04, SD = 5.06). All of the infants and toddlers participating in this study were receiving services through the Louisiana EarlySteps program. EarlySteps is Louisiana’s Early Intervention System under the Individuals with Disabilities Education Act, Part C, which provides services to infants and toddlers and their families from birth to 36 months. Children qualify if they had a medical condition likely to result in a developmental delay, or had an intensified developmental delay. In addition, all participants were currently being observed in a broad investigative study of early childhood development. This broader study was related to the formulation and utility of the BISCUIT battery of assessments. All participants in this sample were determined to be atypically developing by their family pediatrician on development milestones, identified genetic disorders (e.g., Down’s syndrome) or physical disabilities. Co-occurring autism spectrum disorders were a rule out for this study given the high and distinct behavior profiles of comorbid psychopathology evinced by this disorder. Some of the medical conditions represented in the sample included asthma (n = 32), global developmental delay (n = 24), epilepsy (n = 17), Down’s syndrome (n = 15), cerebral palsy (n = 11), spina bifida (n = 3), traumatic brain injury (n = 3), diabetes (n = 3), hydrocephaly (n = 2), hypotonia (n = 2), bronchopulmonary dysplasia (n = 2), and tubular sclerosis (n = 2). There were both males (n = 447) and females (n = 204) included in this sample. Ethnic representation of the participants was Caucasian (56.2%), African American (37.9%), Hispanic (2.6%), and other ethnic origins (3.3%). 1.2. Measure The Baby and Infant Screen for Children with aUtIsm Traits – Part 2 (BISCUIT-Part 2). The BISCUIT-Part 2 is an assessment measures that is part of a comprehensive assessment battery, the Baby and Infant Scale for Children with aUtIsm Traits (BISCUIT). The BISCUIT-Part 1 was developed to measure symptoms of ASD and associated problems in toddlers who are between 17 and 37 months of age. Part 2 of the scale measures symptoms of comorbid psychopathology in those with developmental disabilities. Part 3 of the BISCUIT assessed for problem behaviors in children and toddlers who are developmentally delayed. For the purposes of this study, only Part 2 of the BISCUIT was investigated. The BISCUIT-Part 2 is a 57 item measure used to examine comorbidity in infants and toddlers with Autism Spectrum Disorders (ASD). Parents or guardians rate each item on a 3-point Likert-type scale with severity ratings ranging from ‘‘0 = not a problem or impairment; not at all,’’ ‘‘1 = mild problem or impairment,’’ and ‘‘2 = severe problem or impairment.’’ A factor analyses of the BISCUIT-Part 2 yielded a 5 factor solution: (1) Tantrum/Conduct Problems, (2) Inattention/Impulsivity, (3) Avoidance Behavior, (4) Anxiety/Repetitive Behavior, and (5) Eating Problems/Sleeping (Matson, Boisjoli, Hess &
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Wilkins, submitted for publication). Furthermore, research examining the reliability of the BISCUITPart 3 found excellent reliability with an overall internal consistency coefficient of .96 (Matson et al., 2009). 1.3. Testers and test administration The BISCUIT-Part 2 was administered in a one-to-one parent interview. All interviews were conducted by professionals qualified to provide services for the State of Louisiana’s Early Intervention System under the Individual’s with Disabilities Education Act, Part C. These individuals were certified or licensed in their discipline, and held degrees ranging from bachelors to doctoral level in areas including psychology, education, social work, early childhood development, speech-language pathology, or physical therapy. Additionally, all assessors attended a full day training on BISCUIT administration, scale development, and ASD background information. 1.4. Research design To determine cutoff points for the BISCUIT-Part 2 the standard deviation from the central tendency method was used. Although this is not a normally distributed sample, it is, nevertheless, representative of infants and toddlers with developmental delays, not including an ASD. Therefore, the mean was used as the measure of central tendency. Items comprising each of the five subscales were summed to obtain total subscale scores, as well as a total score representing overall comorbid problems. The mean and standard deviation for the total score and each subscale was calculated. One standard deviation above or, if applicable, one standard deviation below this score was used to delineate clinical significance (Kendall & Grove, 1988). Scores one standard deviation or below the mean were labeled ‘no/minimal impairments,’ scores above one standard deviation and less than or equal to two standard deviations of the mean were classified as having ‘moderate impairment’, and scores greater than two standard deviations of the mean are considered to have ‘severe impairment.’ Cutoff scores were calculated based on two decimal places, and final cutoff scores were set based on rounded whole numbers. 2. Results The mean for the total BISCUIT-Part 2 score was calculated to be 5.84, with a standard deviation of 8.23. Scores that fell one standard deviation or below the mean classified participants as ‘no/minimal impairment,’ scores above one standard deviation and less than or equal to two standard deviations above the mean classified participants as ‘moderate impairment,’ and scores above two standard deviations of the mean classified participants as having ‘severe impairment.’ Thus the cutoff scores calculated for the no/minimal impairment group fell between 0 and 14, the moderate impairment group between 15 and 22, and those scoring above a 23 we classified as having severe impairments. Next, the means and standard deviations for each of the five subscales of the BISCUIT-Part 2 were calculated. The means and standard deviations are as follows: tantrum/conduct behavior, mean = 2.49, SD = 4.10; inattention/impulsivity, mean = 2.11, SD = 3.46; avoidance behavior, mean = 0.35, SD = 1.09; anxiety/repetitive behavior, mean = 0.28, SD = 0.87; and, eating problems/ sleep, mean = 0.61, SD = 1.20. The standard deviation method was also employed to establish cutoffs for each of the BISCUIT-Part 2 subscales. Therefore, those individuals whose subscale score fell one standard deviation and below the mean were classified as having ‘no/minimal impairment’, scores greater than one standard deviation and less then or equal to two standard deviations above the mean classified the participants as ‘moderate impairment,’ and scores greater than two standard deviations of the mean classified the participants as ‘severe impairment’ (see Table 1). 3. Discussion The purpose of Study 1 was to establish norms and cutoff scores based on standard deviations for total score, and subscales which had previously been established via factor analysis. Given the
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Table 1 Subscale means, standard deviations, and cutoff scores.
Tantrum/conduct behavior Inattention/impulsivity Avoidance behavior Anxiety/repetitive Behavior Eating problems/sleep
Mean
SD
No/minimal impairment
Moderate impairment
Severe impairment
2.49 2.11 0.35 0.28 0.61
4.10 3.46 1.09 0.87 1.20
6 5 1 1 1
10 9 2 2 3
11 10 3 3 4
Note. Means and standard deviations for the subscales of the BISCUIT-Part 2 are presented. The standard deviation from central tendency method was used to develop the cutoff scores for no/minimal impairment, moderate impairment, and severe impairment.
emphasis on early childhood intervention, and continued focus on attempts to identify problems in children at very early ages made these date timely. 4. Study 2 The purpose of Study 2 was to examine the frequency of various comorbid problems in this particular population of infants and toddlers who were atypically developing and, also, to determine the appropriateness of each BISCUIT-Part 2 item for comorbid problem severity groups. First, total group data was calculated, followed by an examination of items based on gender and verbal ability. Next, internal consistency correlations were calculated. These procedures were conducted to offer a more fine-grained analysis of the association between atypical infant development and comorbid symptoms. The same procedures, including diagnosis of participants, measures used, administration technique, and data collection, were employed as in Study 1. 4.1. Results Total comorbid difficulties for the individuals were measured by the sum of responses to the 57 BISCUIT-Part 2 items (with scores ranging from 0 to 50). An item analysis was conducted to determine the frequency with which each item was endorsed. Table 2 lists these item endorsements in their respective subdomain. Items that were endorsed as occurring most frequently fell under the tantrum/ conduct behavior and inattention/impulsivity subdomains. These items were easily becomes upset (34.25%), tantrums (28.73%), easily become angry (21.91%), and concentration problems (21.51%), and always ‘‘on the go’’ (21.51%). It is important to note that out of the 57 total items, 26 had an item endorsement of less than 5% of the sample. The frequency with which each of the separate comorbid problems occurred was calculated. Table 3 lists this data by BISCUIT-Part 2 subdomains. When the severity of the comorbid problem (i.e., no/minimal impairment, moderate impairment, and severe impairment) was accounted for, 573 (88.02%) participants were noted to have no/minimal problems on the tantrum/conduct behavior subscale, 40 (6.14%) had moderate problems, and 38 (5.84%) had severe problems. For the inattention/ Table 2 Frequency of item endorsement as a mild problem/impairment or a severe problem/impairment. BISCUIT-Part 2 items Tantrum/conduct behavior Easily becomes upset Tantrums Easily becomes angry Interrupts the activities of others Waits for his/her turn Intrudes upon the activities of others
Overall endorsement (n = 651), F (%) 223 187 142 99 81 81
(34.25) (28.73) (21.81) (15.21) (12.44) (12.44)
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Table 2 (Continued ) BISCUIT-Part 2 items Crying Destroys others’ property Irritable mood Physically cruel to people or animals Spiteful, vindictive, revengeful, or wanting to get back at others Damages property Deliberately annoys others Initiates fights Noisy while playing Tearful or weepy Bullies, threatens, or intimidates others Talk excessively Loses belongings
Overall endorsement (n = 651), F (%) 79 57 53 43 43 41 38 37 35 32 29 8 8
(12.14) (8.76) (8.14) (6.61) (6.61) (6.30) (5.84) (5.68) (5.38) (4.92) (4.45) (1.23) (1.23)
Inattention/impulsivity Concentration problems Always ‘‘on the go’’ Restless Compliance with demands Sustaining attention in tasks or play activities Has poor concentration Runs and climbs more than others his/her age Listens when spoken to directly Distracted by objects or people in the environment Fidgets or squirms Eats things that are not meant to be eaten Has difficulty making decisions Avoids activities that require sustained mental effort Finishes assigned tasks Engages in behaviors that impair daily routine or activities Persistent or recurring impulses that interfere with activities Avoids specific objects, persons, or situations causing interference with his/her normal routine
140 140 103 88 84 82 80 78 77 72 58 34 33 23 20 17 11
(21.51) (21.51) (15.82) (13.52) (12.90) (12.60) (12.29) (11.98) (11.83) (11.06) (8.91) (5.22) (5.07) (3.53) (3.07) (2.61) (1.69)
Avoidance behavior Unreasonable fear of approaching or touching specific objects, people, or animals Withdraws or removes him/herself from social situations Fear of being around others in school, at home, or in social situations Trembles or shakes in the presence of specific objects or situations Exposure to specific object/situation provokes immediate distress that is not age appropriate Avoids specific situations, people, or events Persistent fear that is not age appropriate Avoids specific objects, persons, or situations causing interference with his/her normal routine Presentation of a specific object or situation results in loss of control, panic, or fainting
51 36 27 22 17 13 12 11 10
(7.83) (5.53) (4.15) (3.37) (2.61) (2.00) (1.84) (1.69) (1.54)
Anxiety/repetitive behavior Repetition of actions or words to reduce stress Trembles or shakes in the presence of specific objects or situations Engages in repetitive behaviors for no apparent reason or to reduce stress Ordering of objects for no apparent reason or to reduce stress Persistent or recurring impulses that interfere with activities Sudden, rapid, repetitive movement or vocalization that occurs for no apparent reason Sudden, rapid, repetitive movements or vocalizations that are not associated with a disability Checking on play objects excessively Has difficulty organizing tasks, activities, and belongings Groups of sudden, rapid, repetitive movements/vocalizations occurring together in a chain or cluster Engages in repetitive mental acts for no apparent reason
24 22 23 17 17 13 13 8 7 3 3
(3.69) (3.38) (3.53) (2.61) (2.61) (2.00) (2.00) (1.23) (1.08) (0.46) (0.46)
Eating problems/sleeping Will eat only certain foods Has trouble sleeping Eats too little Has a poor appetite
98 84 76 66
(15.05) (12.90) (11.67) (10.14)
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J.L. Matson et al. / Research in Developmental Disabilities 30 (2009) 1221–1228 Table 3 Frequency and percentage of comorbid severity. Atypically developing (n = 651); F (%) Tantrum/conduct behavior No/minimal impairment Moderate impairment Severe impairment
573 (88.02) 40 (6.14) 38 (5.84)
Inattention/impulsivity No/minimal impairment Moderate impairment Severe impairment
571 (87.71) 43 (6.61) 37 (5.68)
Avoidance behavior No/minimal impairment Moderate impairment Severe impairment
605 (92.93) 21 (3.23) 25 (3.84)
Anxiety/repetitive behavior No/minimal impairment Moderate impairment Severe impairment
610 (93.70) 27 (4.15) 14 (2.15)
Eating problems/sleep No/minimal impairment Moderate impairment Severe impairment
546 (83.88) 81 (12.44) 24 (3.69)
impulsivity subscale, 571 (87.71%) were determined to be in the no/minimal impairment group, 43 (6.61%) were in the moderate impairment group, and 37 (5.68%) were in the severe impairment group. For the avoidance behavior subscale, 605 (92.93%) had no/minimal impairment, 21 (3.23%) had moderate impairment, and 25 (3.84%) had severe impairment. There were 610 (93.70%) infants and toddlers noted to have no/minimal impairment on the anxiety/repetitive behavior subscale with 27 (4.15%) having moderate impairment and 14 (2.15%) with severe impairment. Finally, for the eating problems/sleep subscale, 546 (83.88%) were determined to have no/minimal impairment with the other participants having moderate (n = 81; 12.44%) or severe (n = 24; 3.69%) impairment. It appears that across all subdomains a general trend emerges. That is, as severity increases, less children who are noted to be atypically developing evince significant impairment with respect to comorbid psychopathology. In addition, the frequency with which participants had multiple comorbid problems was calculated. This was computed using total subdomain severity cutoffs for the total sample as noted in Table 4. The outcomes of this analysis indicates that atypically developing toddlers have a greater probability of having no/minimal or moderate impairments, rather than severe impairments in a psychopathology domain 86.18%). To evaluate the appropriateness of each item of the BISCUIT-Part 2 according to groups, an item analysis was conducted. The variance of each item for the three comorbidity impairment severity groups, using the pre-established cutoff points to the no/minimal impairment, moderate impairment, and severe impairment groups, was calculated and those items with near-zero values were noted. Additionally, the correlations for each item and its respective subscale were calculated. For the no/ Table 4 Frequency and percentage of BISCUIT-Part 2 problem areas rated in the severe impairment. Atypically developing (n = 651); F (%) No subdomain in the severe range One subdomain in the severe range Two subdomains in the severe range Three or more subdomains in the severe range
561 59 17 12
(86.18%) (9.06%) (2.61%) (1.84%)
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minimal impairment group 46 out of the 57 items had near-zero variance, the moderate impairment group had 11 items with near-zero variance, and the severe impairment group had three items with near-zero variances. Using all of the participants combined, the variances for all items of the BISCUITPart 2 were then calculated; there were 30 items with near-zero variance observed. Alpha values for item-scale correlations of its respective subscale were calculated along with the overall alpha for that subscale. The tantrum/conduct behavior subscale had an alpha ranging from 0.14 to 0.68 and 0.88 for the items and subscale, respectively. The inattention/impulsivity subscale had item-scale alphas ranging from 0.16 to 0.65 and 0.84 for the subscale. The avoidance behavior subscale had alphas ranging from 0.34 to 0.50 and an overall alpha for the subscale of 0.71. Alpha values for the item-scale correlations of the anxiety/repetitive behavior subscale ranged from 0.12 to 0.44 with an overall alpha of 0.57. Lastly, the eating problems/sleeping subscale had item-scale correlations ranging from 0.13 to .63 with an overall alpha of 0.66. 4.2. Discussion The psychometric properties of the BISCUIT-Part 2 were extended to cutoff scores and norms for infants and toddlers who are at risk for developmental disabilities. Given the increasing focus on early intervention and treatment of children with developmental disabilities, such data are needed and timely (Matson, 2007a; Matson, Nebel-Schwalm, & Matson, 2007; Smith, Groen, & Wynne, 2000). Furthermore, comprehensive assessments which look not only at core symptoms, but related comorbid symptoms and syndromes are advisable (Matson, 2007b; Matson & Nebel-Schwalm, 2007; Rogers & DiLalla, 1991). These points are underscored by the ability of the BISCUIT-Part 2 to detect these behaviors in very young children. Problems in eating and sleeping were most frequent, constituting approximately 16% of the sample. This finding is consistent with data suggesting that neurodevelopmental disorders can effect daytime functioning (Goldman, Malow, Newman, Roof, & Dykens, 2009). Furthermore, these problems persist without treatment (Lancioni, O’Reilly, & Basil, 1999). For the most serious behavior category, inattention/impulsivity and tantrums/conduct behavior problems were most common. Comorbid behavior problems is a common problem in persons with developmental disabilities, is a major stressor for parents and children (Emerson, 2003; Kiernan & Alborz, 1995; Murphy et al., 2005). However, this paper advances our knowledge about these behaviors with very young children. We further broke our analysis down by individual items. One hundred and eighty-seven children evinced tantrums, while 223 were easily upset. Thus, externalizing behaviors which have been shown in adult populations to have very negative impacts on adjustment are common (McClintock, Hall, & Oliver, 2003). Being able to identify these behaviors that may be early predictors of later psychopathy is important given the benefits early intervention can have on the long-term prognosis for the child. Furthermore, children who are developmentally delayed oftentimes evince behaviors which impact the child’s ability to learn and be successful in his or her social environment. Thus, the BISCUIT-Part 2 appears to have utility for identifying target behaviors in need of remediation. However, much more research is needed to bring attention to this oftentimes under recognized topic in those who are developmentally delayed, especially in the very young. References Agaliotis, I., & Kalyva, E. (2008). Nonverbal social interaction skills of children with learning disabilities. Research in Developmental Disabilities, 29, 1–10. Eikeseth, S. (2009). Outcome of comprehensive psycho-educational interventions for young children with autism. Research in Developmental Disabilities, 30, 158–178. Emerson, E. (2003). Mothers of children and adolescents with intellectual disability: Social and economic situation, mental health status, and the self-assessed social and psychological impact of the child’s difficulties. Journal of Intellectual Disabilities Research, 47, 385–399. Goldman, S. E., Malow, B. A., Newman, K. D., Roof, E., & Dykens, E. M. (2009). Sleep patterns and daytime sleepiness in adolescents and young adults with Williams Syndrome. Journal of Intellectual Disability Research, 53, 182–188. Hsieh, H. C. (2008). Effects of ordinary and adaptive toys on pre-school children with developmental disabilities. Research in Developmental Disabilities, 29, 459–466. Kendall, P. C., & Grove, W. M. (1988). Normative comparisons in therapy outcome. Behavioral Assessment, 10, 147–158. Kiernan, C., & Alborz, A. (1995). A different life. Manchester: Hester Adrian Research Centre.
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Lancioni, G. E., O’Reilly, M. F., & Basil, G. (1999). Review of strategies for treating sleep problems in persons with severe or profound mental retardation or multiple handicaps. American Journal of Mental Retardation, 104, 170–186. Lifshitz, H., Merrick, J., & Morad, M. (2008). Health status and ADl functioning of older person with intellectual disability: Community residence versus residential care centers. Research in Developmental Disabilities, 29, 301–315. Matson, J. L. (2007a). Current status of differential diagnosis for children with autism spectrum disorders. Research in Developmental Disabilities, 28, 109–118. Matson, J. L. (2007b). Determining treatment outcome in early intervention programs for autism spectrum disorders: A critical analysis of measurement issues in learning based procedures. Research in Developmental Disabilities, 28, 207–218. Matson, J. L., Boisjoli, J. A., Hess, J., & Wilkins, J. (submitted for publication). Comorbid psychopathology factor structure on the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT). Comprehensive Psychiatry. Matson, J. L., Cooper, C., Malone, C. J., & Moskow, S. L. (2008a). The relationship of self-injurious behavior and other maladaptive behaviors among individuals with severe and profound intellectual disability. Research in Developmental Disabilities, 29, 141–148. Matson, J. L., Kiely, S. L., & Bamburg, J. W. (1997). The effect of stereotypes on adaptive skills as assessed with the DASH-II and Vineland Adaptive Behavior Scales. Research in Developmental Disabilities, 11, 471–476. Matson, J. L., & Nebel-Schwalm, M. (2007). Comorbid psychopathology with autism spectrum disorders in children: An overview. Research in Developmental Disabilities, 28, 341–352. Matson, J. L., Nebel-Schwalm, M., & Matson, M. L. (2007). A review of methodological issues in the differential diagnosis of autism spectrum disorders in children. Research in Autism Spectrum Disorders, 1, 38–54. Matson, J. L., Smiroldo, B. B., & Bamburg, J. W. (1998). The relationship of social skills to psychopathology for individuals with severe or profound mental retardation. Journal of Intellectual and Developmental Disability, 19, 89–95. Matson, J. L., & Smith, K. R. M. (2008). Current status of intensive behavioral interventions for young children with autism and PDDNOS. Research in Autism Spectrum Disorders, 2, 60–74. Matson, J. L., Wilkins, J., & Gonzales, M. (2008b). Early identification and diagnosis in autism spectrum disorders in young children and infants; how early is to early? Research in Autism Spectrum Disorders, 2, 75–84. Matson, J. L., Wilkins, J., Sevin, J. A., Knight, C., Boisjoli, J. A., & Sharp, B. (2009). Reliability and Item Content of the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT): Parts 1, 2, and 3. Research in Autism Spectrum Disorders, 3, 336–344. McClintock, K., Hall, S., & Oliver, C. (2003). Risk markers associated with challenging behaviours in people with intellectual disabilities: A meta-analytic study. Journal of Intellectual Disability Research, 47(6), 405–416. Mitchell, D. B., & Hauser-Cram, P. (2008). The well-being of mothers of adolescents with developmental disabilities in relation to medical care utilization and satisfaction with health care. Research in Developmental Disabilities, 29, 97–112. Murphy, G. H., Beadle-Brown, J., Wing, L., Gould, J., Shah, A., & Holmes, N. (2005). Chronicity of challenging behaviors in people with severe intellectual disabilities and/or autism: A total population sample. Journal of Autism and Developmental Disorders, 35, 405–418. Myrbakk, E., & von Tetzchner, S. (2008). Psychiatric disorders and behavior problems in people with intellectual disability. Research in Developmental Disabilities, 29, 316–332. Paclawskyj, T. R., Matson, J. L., Bamburg, J. W., & Baglio, C. S. (1997). A comparison of the Diagnostic Assessment for the Severely Handicapped-II (DASH-II) and the Aberrant Behavior Checklist (ABC). Research in Developmental Disabilities, 18, 289–298. Ringdahl, J. E., Call, N. A., Mews, J. B., Boelter, E. W., & Christensen, T. J. (2008). Assessment and treatment of aggressive behavior without a clear social function. Research in Developmental Disabilities, 29, 351–362. Rogers, S. J., & DiLalla, D. L. (1991). A comprehensive study of the effects of a developmentally based instructional model on young children with autism and young children with other disorders of behavior and development. Topics in Early Childhood Special Education, 11, 29–47. Smith, T., Groen, A. D., & Wynne, J. W. (2000). Randomized trial of intensive early intervention or children with pervasive development disorder. American Journal on Mental Retardation, 105, 269–285.