- Email: [email protected]
Quality of Life after Adenotonsillectomy for SDB in Children
Otolaryngology–Head and Neck Surgery (2005) 133, 569-572
ORIGINAL RESEARCH
Quality of Life after Adenotonsillectomy for SDB in Children Ron B. Mitchell, MD, and James Kelly, PHD, Albuquerque, New Mexico OBJECTIVE: To evaluate the relationship between quality of life and the relative severity of sleep-disordered breathing (SDB) and to compare changes in quality of life after adenotonsillectomy in children with similar demographics but with either obstructive sleep apnea syndrome (OSAS) or with milder forms of SDB. STUDY DESIGN AND SETTING: All study participants underwent polysomnography to document the severity of SDB. The effectiveness of adenotonsillectomy for the relief of SDB was evaluated by using the OSA-18 quality of life survey (OSA-18). Preoperative and postoperative OSA-18 scores for each group of children (OSAS and mild SDB) were compared by using a repeated measures ANOVA. Changes between the 2 groups were compared by using an analysis of covariance with the preoperative score as a covariate. RESULTS: The study population included 61 children, 43 with OSAS and 18 with mild SDB. The demographics in the 2 groups were similar. The mean apnea-hypopnea index for children with OSAS was 21 (range, 5-46), and for children with mild SDB, it was 3 (range 0-4.9). The total OSA-18 score and the scores for all domains showed significant improvement after surgery for both groups of children (P ⬍ .001). A comparison of mean difference in total and domain scores for the 2 groups of children was not significant. CONCLUSIONS AND SIGNIFICANCE: Preoperative values for the OSA-18 total and domain scores are high in children with either OSAS or mild SDB. Both groups of children show a dramatic improvement in quality of life after adenotonsillectomy and the degree of improvement is similar. Fortunately, surgical therapy with adenotonsillectomy is associated with marked improvement in quality of life for children with either OSAS or mild SDB. © 2005 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
tom of mild SDB, whereas obstructive apnea and hypopnea characterize severe SDB. It is not always possible to distinguish OSAS from milder forms of obstruction solely on the basis of clinical criteria.1 Polysomnography is used to make the differential diagnosis in these instances by documenting the presence of snoring with or without apnea or hypopnea during sleep.2 Unfortunately, polysomnography is expensive and may not be available in all hospital facilities. As a consequence, many studies of the outcome of adenotonsillectomy for SDB have not separated children with mild airway obstruction evidenced by primary snoring from those with OSAS. This practice has been justified by the fact that adenotonsillectomy is the recommended surgical therapy for both conditions.3 In the present study, changes in quality of life after adenotonsillectomy were evaluated in children with OSAS and in children with comparable demographics but milder forms of SDB. All children included in the study underwent polysomnography to establish the presence of SDB and its severity. The goals of the study were to evaluate the relationship between quality of life and the relative severity of SDB and to compare changes in quality of life after adenotonsillectomy in children with similar demographics but with either OSAS or with milder forms of SDB.
METHODS
leep-disordered breathing (SDB) in children ranges from mild airway obstruction to obstructive sleep apnea syndrome (OSAS). Primary snoring is the principal symp-
Approval for this study was obtained from the institutional review board of the University of New Mexico. The caregivers of children enrolled in the study signed an informed consent document. Children referred to the Pediatric Otolaryngology Service with a sleep disturbance who underwent polysomnography were included in the study. Demographic information
From the Departments of Surgery (Drs Mitchell and Kelly) and Pediatrics (Dr Mitchell), University of New Mexico, Health Sciences Center. Reprint requests: Ron B. Mitchell, MD, Virginia Commonwealth Uni-
versity, Department of Otolaryngology, PO Box 980146, Richmond, VA 23298. E-mail, [email protected].
S
0194-5998/$30.00 © 2005 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved. doi:10.1016/j.otohns.2005.05.040
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Otolaryngology–Head and Neck Surgery, Vol 133, No 4, October 2005
was collected for both caregiver and child. Exclusion criteria included the following: (1) children younger than 3 or older than 18 years of age; (2) children who previously had had an adenotonsillectomy; and (3) children with craniofacial syndromes, neuromuscular disease, developmental delay, or mild psychiatric disorders. The effectiveness of adenotonsillectomy for the relief of SDB was evaluated by using the OSA-18 quality of life survey (OSA-18).4 The OSA-18 comprises 18 items in 5 domains of sleep disturbance, physical suffering, emotional distress, daytime problems, and caregiver concerns. The domains of emotional distress and daytime problems contain 3 items, whereas the other domains contain 4. A point scale is used ranging from 1 (⫽ none of the time) to 7 (⫽ all of the time) to grade the relative severity of the problem addressed in each item. The total score and domain scores were recorded. All study participants underwent polysomnography5 to document the severity of SDB. The following parameters were measured: 4-channel electroencephalography with bilateral central and occipital leads; electro-oculography to measure vertical and horizontal eye movements; electromyography with submental electrodes; electrocardiography; airflow recording through the nose and mouth by a nasal air pressure transducer with end tidal CO2; thoracic and abdominal effort by piezoelectric sensors; oxygen saturation through pulse oximetry; and tracheal sound recording by using a microphone secured to the neck. Digital videotaping with sound recording was performed throughout the night. A sleep medicine physician interpreted the PSG results. The apnea-hypopnea index (AHI), defined as the average number of obstructive apneas and hypopneas per hour of sleep, was used for diagnosis of OSAS. Obstructive apnea was defined as total absence of airflow through the mouth and nose with continued chest and abdominal movement for at least 2 respiratory cycles. Hypopneas were defined as a decrease in nasal flow with a corresponding decrease in SpO2 of ⱖ 4% and/or with an arousal.2,5 OSAS was defined as an AHI of at least 5 or an apnea index (AI) of more than 1. Children with an AHI of less than 5 and an AI of less than 1 were included in the study and considered to have mild SDB.6 Caregivers were asked to complete the 1st OSA-18 survey before polysomnography. Children with SDB underwent a monopolar Bovie adenotonsillectomy. Caregivers for these children were asked to complete the OSA-18 survey a 2nd time within 6 months of surgery. Subtracting the mean postoperative score from the mean preoperative score derived the difference score. Because a decrease in mean score implies improvement, the mean change is a positive number. The 95% confidence intervals (95% CI) for difference scores also were calculated. The standardized response mean (SRM), defined as the difference score divided by the standard deviation of the difference score, was used to estimate the extent of improvement after surgery. OSA-18 total scores on the 1st survey were classified as follows: mild (⬍60), moderate (ⱖ60, ⱕ80), or severe
(⬎80).4 Preoperative and postoperative OSA-18 scores for each group of children (OSAS and mild SDB) were compared by using a repeated-measures ANOVA. Changes between the 2 groups were compared by using an analysis of covariance with the preoperative score as a covariate. SAS procedures (SAS Corp., Carey, NC) were used for statistical analyses. A power analysis indicated that a sample size of 16 is adequate to detect a 20-point difference in OSA-18 total score with 80% power and ␣ ⫽ .05. On the basis of the original study by Franco et al,4 a change in OSA-18 total score from 80 to 60 indicates a change from severe to moderate impact on quality of life. Therefore, the present study has sufficient power to detect a clinically important change in quality of life on the basis of OSA-18 total score.
RESULTS Sixty-nine children were included in the study. Four of these children were lost to follow-up, 2 others did not undergo surgical therapy, and the caregivers for 2 children did not complete the postoperative OSA-18 survey. As a consequence, the study population included 61 children, 43 with OSAS and 18 children with mild SDB. The demographics in the 2 groups (OSAS and mild SDB) were similar and are presented in Table 1. The mean AHI for children with OSAS was 21 (range, 5-46), and for children with mild SDB, it was 3 (range, 0-4.9). OSA-18 scores before and after adenotonsillectomy for children with OSAS and for children with mild SDB are presented in Table 2. The follow-up was short at 47.7 days in the OSAS group and 50.4 days in the mild SDB group. The total OSA-18 score and the scores for all domains showed significant improvement after surgery for both groups of children (P ⬍ .001). The mean preoperative total and domain scores for children with OSAS generally were higher than for children with mild SDB. The exception was for the domain of daytime problems, in which the mean preoperative score was higher for children with mild SDB than for children with OSAS. These differences were not statistically significant. The mean total OSA-18 scores before surgery were 72.8 (median, 74.1) and 69.4 (median, 69.7), and after surgery, they were 41.0 (median, 30.1) and 36.7 (median, 30.2) for children with OSAS and for children with mild SDB, respectively. The mean difference in total scores was 31.8 (SRM, 1.0) and 32.7 (SRM, 1.9) for children with OSAS and for children with mild SDB, respectively. The domain with the largest mean difference score was physical suffering, and the one with the smallest was for emotional distress. A comparison of mean difference in total and domain scores for the 2 groups of children was not significant. In the OSAS group, 16 children (37%) had a high OSA-18 total score preoperatively (⬎80), 15 (35%) had a moderate score (⬎60, ⬍80), and 12 (28%) had a low score (⬍60). Postoperatively, only 4 (9%) had a high score, 2
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Quality of Life after Adenotonsillectomy for SDB in . . .
571
Table 1 Characteristics of the Study Population Study Population Mean age (Range) Percentage Male BMI7 Hispanic or Latino Non-Hispanic or Latino White Mean interval between pre-operative OSA-18 and Adenotonsillectomy (Days) Adenotonsillectomy and post-operative OSA-18 (Days) Mean interval between pre-operative and post-operative OSA-18 (Days) AHI (Range)
Children with OSAS (n⫽ 43)
Children with mild SDB (n ⫽ 18)
7 (3-17) 69% 23 (12-48) 51% 47% 90.7
7 (3-15) 67% 21 (12-43) 59% 39% 75.1
47.7
50.4
138.4
125.8
21 (10-46)
(5%) had a moderate score, and 37 (86%) had a low score. In the mild SDB group, 4 children (22%) had a high OSA-18 total score preoperatively, 11 (61%) had a moderate score, and 3 (17%) had a low score. Postoperatively, only 1 (6%) had a high score, 2 (11%) had a moderate score, and 15 (83%) had a low score. In the OSAS group, 39 children (91%) improved their OSA-18 total score, and 4 (9%) got worse. In the mild SDB group, 17 children (94%) improved, 1 (6%) stayed the same, and none got worse. The pattern of change in the OSA-18 survey items after surgery is illustrated graphically in Figure 1. The pattern of scores for the domains is remarkably similar before and after surgery and there is an improvement in mean score for each domain. The domain of emotional distress shows the least improvement. The total score of the survey and all domains showed a significant change after surgery both in children with OSAS and in children with mild SDB.
DISCUSSION In the present study, preoperative values for the OSA-18 total score and for most domain scores were higher for children with
3 (0.0-4.9)
OSAS than for children with mild SDB, but this difference was not significant. Improvements in quality of life measured by reductions in scores for the 5 domains of the OSA-18 postoperatively are dramatic regardless of the severity of SDB. Caregivers of children with SDB report a significant improvement in quality of life after adenotonsillectomy, regardless of the severity of the underlying disorder. The domains with the highest preoperative scores and the biggest changes after surgery were physical suffering and caregiver concerns. The domain of physical suffering asks the caregivers to rate the frequency of snoring, restless sleep, and breath-holding spells at night in their child. The domain of caregiver concerns asks about the caregiver’s worry about, and frustrations with, the child. These factors are rated highly preoperatively in children with SDB regardless of severity and respond most significantly to surgical therapy. The domains of emotional distress and daytime problems had the lowest preoperative scores and the smallest change after surgery. The domain of emotional distress asks about mood swings, aggressive and hyperactive behaviors, and temper tantrums. The domain of daytime problems asks about excessive daytime sleepiness, poor concentration, and difficulty getting out of bed
Table 2 Mean Pre- and Post-operative OSA Scores for Children with Moderate to Severe OSAS and Children with Mild SDB OSA-18 Total Score*
Children with OSAS Survey 1 Survey 2 Children with Mild SDB Survey 1 Survey 2
Children with OSAS (n⫽ 43)
Mean
95% CI
Sleep Disturbance
95% CI
Physical Suffering
95% CI
Emotional Distress
95% CI
Daytime Problems
95% CI
Caregiver Concerns
95% CI
72.8 41.0
67.3-78.5 33.6-48.4
18.7 8.4
16.8-20.5 6.5-10.3
14.6 8.9
12.8-16.3 7.3-10.4
11.5 8.4
9.9-13.2 6.9-9.9
11.4 7.4
9.8-13.0 5.9-8.9
16.5 7.8
14.5-18.4 6.0-9.6
69.4 36.7
60.2-78.6 27.1-46.2
17.6 6.8
15.0-20.2 4.8-8.8
14.4 8.2
12.1-16.6 5.5-10.8
9.5 6.8
6.9-12.1 4.7-9.0
12.2 7.4
10.1-14.3 5.1-9.8
15.7 7.4
13.0-18.4 4.8-10.0
*p-values ⬍.0001 for mean total dcores and mean domain scores of survey 1 vs. survey 2 for both groups of children.
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Otolaryngology–Head and Neck Surgery, Vol 133, No 4, October 2005 preoperative score- OSAS postoperative scores-OSAS
OSA-18 Domain scores
20.0
preoperative scores- Mild SDB postoperative scores-Mild SDB
15.0 10.0 5.0 0.0 Sleep disturbance
physical suffering
emotional distress
daytime problems
caregiver concerns
Figure 1 Pre- and postoperative OSA-187 domain scores for hcildren with OSAS and Mild SDB.
in the morning. It is interesting that the domain of daytime problems was the only domain in which the mean score for the mild SDB group was higher than for the OSAS group. Again the improvements postoperatively appear independent of the severity of SDB. Preoperatively, on the basis of the OSA-18 total score, 37% of children with OSAS and 22% of children with mild SDB had values that were consistent with a high impact on healthrelated quality of life. Postoperatively, in both groups, ⬍10% of children remained in the same group. Equally, ⬎90% of children with SDB improved their scores postoperatively regardless of the severity of SDB. It is clear that surgical therapy is associated with dramatic improvements in children’s quality of life even when the condition is mild. There is increasing evidence that mild airway obstruction evidenced by primary snoring is far from benign. Blunden et al7 showed that children with primary snoring had reduced neurocognitive performance compared with controls. This included deficits in attention, memory, and intelligence scores. Kennedy et al8 showed that children with primary snoring had reduced verbal and global IQ scores and reduced attention and memory compared with controls. O’Brien et al9 showed that children with primary snoring, in a sample of children from the community who did not seek medical intervention, had lowered neurocognitive function compared with nonsnoring children. These studies have not compared children with primary snoring with children with OSAS and have not shown that intervention with adenotonsillectomy leads to improvements in behavior. Nonetheless, they highlight the need for further studies in children with primary snoring and other forms of mild SDB. This is especially true because behavioral problems may be more prevalent in children with mild rather than severe OSAS.10 In this study, mild SDB was defined as an AHI of less than 5 and an AI of less than 1. The mean AHI for children with mild SDB was 3. This includes children with primary snoring, upper airway resistance syndrome,11 and mild OSAS. We also studied children with a sleep disturbance that was symptomatic enough to request medical intervention. This may represent a selection bias. Caregivers of children who have persistent or worsening symptoms are more likely to seek surgical therapy, and these children may benefit to a greater extent than an equivalent community sample. There are a number of other limitations to this study. We did not have a control group. We therefore can conclude that
surgical therapy for SDB is associated with an improvement in quality of life but cannot infer causality. There also are no long-term data to report. It is possible that improvements in quality of life are maintained in the long term in children with OSAS to a greater degree than in children with mild SDB.12-14 Finally, the small number of children in this study did not allow us to compare the improvements in quality of life in different age, ethnic, and body-mass index groups. In summary, preoperative values for the OSA-18 total and domain scores are high in children with either OSAS or mild SDB. Both groups of children show a dramatic improvement in quality of life after adenotonsillectomy, and the degree of improvement is similar. This suggests that even mild forms of SDB evidenced by snoring but only isolated incidents of apnea or hypopnea have a decidedly negative effect on quality of life. It also raises the possibility that mild forms of SDB may have a significantly negative impact on child behavior.7-9 Fortunately, surgical therapy with adenotonsillectomy is associated with marked improvement in quality of life for children with either mild or severe SDB.
REFERENCES 1. Brietzke SE, Katz ES, Roberson DW. Can history and physical examination reliably diagnose pediatric obstructive sleep apnea/hypopnea syndrome? A systematic review of the literature. Otolaryngol Head Neck Surg 2004;131:827–32. 2. Carroll J, Loughlin G. Diagnostic criteria for obstructive sleep apnea syndrome in children. Pediatr Pulmonol 1992;14:71– 4. 3. American Academy of Pediatrics, Section on Pediatric Pulmonology, Subcommittee on Obstructive Sleep Apnea Syndrome. Clinical practice guideline: diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics 2002;109:704 –11. 4. Franco R, Rosenfeld R, Rao M. Quality of life for children with obstructive sleep apnea. Otolarygol Head Neck Surg 2000;123:9 –16. 5. American Thoracic Society. Standards and indications for cardiopulmonary sleep studies in children. Am J Respir Crit Care Med 1996; 153:866 –78. 6. Montgomery-Downs HE, O’Brien LM, Holbrook CR, et al. Snoring and sleep-disordered breathing in young children: subjective and objective correlates. Sleep 2004;27:87–94. 7. Blunden S, Lushington K, Kennedy D, et al. Behavior and neurocognitive performance in children aged 5-10 years who snore compared to controls. J Clin Exp Neuropsychol 2000;22:554 – 68. 8. Kennedy JD, Blunden S, Hirte C, et al. Reduced neurocognition in children who snore. Pediatr Pulmonol 2004;37:330 –7. 9. O’Brien LM, Mervis CB, Holbrook CR, et al. Neurobehavioral implications of habitual snoring in children. Pediatrics 2004;114:44 –9. 10. Lewin DS, Rosen RC, England SJ, et al. Preliminary evidence of behavioral and cognitive sequelae of obstructive sleep apnea in children. Sleep Med 2002;3:5–13. 11. Guilleminault C, Stoohs R, Clerk A, et al. A cause of excessive daytime sleepiness: the upper airway resistance syndrome. Chest 1993; 104:781–7. 12. Mitchell R, Kelly J, Call E, et al. Long-term changes in quality of life after surgery for pediatric obstructive sleep apnea. Arch Otolaryngol Head Neck Surg 2004;130:409 –12. 13. Flanary VA. Long-term effect of adenotonsillectomy on quality of life in pediatric patients. Laryngoscope 2003;113:1639 – 44. 14. Mitchell R, Call E, Yao N, et al. Quality of life after adenotonsillectomy for obstructive sleep apnea in children. Arch Otolaryngol Head Neck Surg 2004;130:190 – 4.
ORIGINAL RESEARCH
Quality of Life after Adenotonsillectomy for SDB in Children Ron B. Mitchell, MD, and James Kelly, PHD, Albuquerque, New Mexico OBJECTIVE: To evaluate the relationship between quality of life and the relative severity of sleep-disordered breathing (SDB) and to compare changes in quality of life after adenotonsillectomy in children with similar demographics but with either obstructive sleep apnea syndrome (OSAS) or with milder forms of SDB. STUDY DESIGN AND SETTING: All study participants underwent polysomnography to document the severity of SDB. The effectiveness of adenotonsillectomy for the relief of SDB was evaluated by using the OSA-18 quality of life survey (OSA-18). Preoperative and postoperative OSA-18 scores for each group of children (OSAS and mild SDB) were compared by using a repeated measures ANOVA. Changes between the 2 groups were compared by using an analysis of covariance with the preoperative score as a covariate. RESULTS: The study population included 61 children, 43 with OSAS and 18 with mild SDB. The demographics in the 2 groups were similar. The mean apnea-hypopnea index for children with OSAS was 21 (range, 5-46), and for children with mild SDB, it was 3 (range 0-4.9). The total OSA-18 score and the scores for all domains showed significant improvement after surgery for both groups of children (P ⬍ .001). A comparison of mean difference in total and domain scores for the 2 groups of children was not significant. CONCLUSIONS AND SIGNIFICANCE: Preoperative values for the OSA-18 total and domain scores are high in children with either OSAS or mild SDB. Both groups of children show a dramatic improvement in quality of life after adenotonsillectomy and the degree of improvement is similar. Fortunately, surgical therapy with adenotonsillectomy is associated with marked improvement in quality of life for children with either OSAS or mild SDB. © 2005 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
tom of mild SDB, whereas obstructive apnea and hypopnea characterize severe SDB. It is not always possible to distinguish OSAS from milder forms of obstruction solely on the basis of clinical criteria.1 Polysomnography is used to make the differential diagnosis in these instances by documenting the presence of snoring with or without apnea or hypopnea during sleep.2 Unfortunately, polysomnography is expensive and may not be available in all hospital facilities. As a consequence, many studies of the outcome of adenotonsillectomy for SDB have not separated children with mild airway obstruction evidenced by primary snoring from those with OSAS. This practice has been justified by the fact that adenotonsillectomy is the recommended surgical therapy for both conditions.3 In the present study, changes in quality of life after adenotonsillectomy were evaluated in children with OSAS and in children with comparable demographics but milder forms of SDB. All children included in the study underwent polysomnography to establish the presence of SDB and its severity. The goals of the study were to evaluate the relationship between quality of life and the relative severity of SDB and to compare changes in quality of life after adenotonsillectomy in children with similar demographics but with either OSAS or with milder forms of SDB.
METHODS
leep-disordered breathing (SDB) in children ranges from mild airway obstruction to obstructive sleep apnea syndrome (OSAS). Primary snoring is the principal symp-
Approval for this study was obtained from the institutional review board of the University of New Mexico. The caregivers of children enrolled in the study signed an informed consent document. Children referred to the Pediatric Otolaryngology Service with a sleep disturbance who underwent polysomnography were included in the study. Demographic information
From the Departments of Surgery (Drs Mitchell and Kelly) and Pediatrics (Dr Mitchell), University of New Mexico, Health Sciences Center. Reprint requests: Ron B. Mitchell, MD, Virginia Commonwealth Uni-
versity, Department of Otolaryngology, PO Box 980146, Richmond, VA 23298. E-mail, [email protected].
S
0194-5998/$30.00 © 2005 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved. doi:10.1016/j.otohns.2005.05.040
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Otolaryngology–Head and Neck Surgery, Vol 133, No 4, October 2005
was collected for both caregiver and child. Exclusion criteria included the following: (1) children younger than 3 or older than 18 years of age; (2) children who previously had had an adenotonsillectomy; and (3) children with craniofacial syndromes, neuromuscular disease, developmental delay, or mild psychiatric disorders. The effectiveness of adenotonsillectomy for the relief of SDB was evaluated by using the OSA-18 quality of life survey (OSA-18).4 The OSA-18 comprises 18 items in 5 domains of sleep disturbance, physical suffering, emotional distress, daytime problems, and caregiver concerns. The domains of emotional distress and daytime problems contain 3 items, whereas the other domains contain 4. A point scale is used ranging from 1 (⫽ none of the time) to 7 (⫽ all of the time) to grade the relative severity of the problem addressed in each item. The total score and domain scores were recorded. All study participants underwent polysomnography5 to document the severity of SDB. The following parameters were measured: 4-channel electroencephalography with bilateral central and occipital leads; electro-oculography to measure vertical and horizontal eye movements; electromyography with submental electrodes; electrocardiography; airflow recording through the nose and mouth by a nasal air pressure transducer with end tidal CO2; thoracic and abdominal effort by piezoelectric sensors; oxygen saturation through pulse oximetry; and tracheal sound recording by using a microphone secured to the neck. Digital videotaping with sound recording was performed throughout the night. A sleep medicine physician interpreted the PSG results. The apnea-hypopnea index (AHI), defined as the average number of obstructive apneas and hypopneas per hour of sleep, was used for diagnosis of OSAS. Obstructive apnea was defined as total absence of airflow through the mouth and nose with continued chest and abdominal movement for at least 2 respiratory cycles. Hypopneas were defined as a decrease in nasal flow with a corresponding decrease in SpO2 of ⱖ 4% and/or with an arousal.2,5 OSAS was defined as an AHI of at least 5 or an apnea index (AI) of more than 1. Children with an AHI of less than 5 and an AI of less than 1 were included in the study and considered to have mild SDB.6 Caregivers were asked to complete the 1st OSA-18 survey before polysomnography. Children with SDB underwent a monopolar Bovie adenotonsillectomy. Caregivers for these children were asked to complete the OSA-18 survey a 2nd time within 6 months of surgery. Subtracting the mean postoperative score from the mean preoperative score derived the difference score. Because a decrease in mean score implies improvement, the mean change is a positive number. The 95% confidence intervals (95% CI) for difference scores also were calculated. The standardized response mean (SRM), defined as the difference score divided by the standard deviation of the difference score, was used to estimate the extent of improvement after surgery. OSA-18 total scores on the 1st survey were classified as follows: mild (⬍60), moderate (ⱖ60, ⱕ80), or severe
(⬎80).4 Preoperative and postoperative OSA-18 scores for each group of children (OSAS and mild SDB) were compared by using a repeated-measures ANOVA. Changes between the 2 groups were compared by using an analysis of covariance with the preoperative score as a covariate. SAS procedures (SAS Corp., Carey, NC) were used for statistical analyses. A power analysis indicated that a sample size of 16 is adequate to detect a 20-point difference in OSA-18 total score with 80% power and ␣ ⫽ .05. On the basis of the original study by Franco et al,4 a change in OSA-18 total score from 80 to 60 indicates a change from severe to moderate impact on quality of life. Therefore, the present study has sufficient power to detect a clinically important change in quality of life on the basis of OSA-18 total score.
RESULTS Sixty-nine children were included in the study. Four of these children were lost to follow-up, 2 others did not undergo surgical therapy, and the caregivers for 2 children did not complete the postoperative OSA-18 survey. As a consequence, the study population included 61 children, 43 with OSAS and 18 children with mild SDB. The demographics in the 2 groups (OSAS and mild SDB) were similar and are presented in Table 1. The mean AHI for children with OSAS was 21 (range, 5-46), and for children with mild SDB, it was 3 (range, 0-4.9). OSA-18 scores before and after adenotonsillectomy for children with OSAS and for children with mild SDB are presented in Table 2. The follow-up was short at 47.7 days in the OSAS group and 50.4 days in the mild SDB group. The total OSA-18 score and the scores for all domains showed significant improvement after surgery for both groups of children (P ⬍ .001). The mean preoperative total and domain scores for children with OSAS generally were higher than for children with mild SDB. The exception was for the domain of daytime problems, in which the mean preoperative score was higher for children with mild SDB than for children with OSAS. These differences were not statistically significant. The mean total OSA-18 scores before surgery were 72.8 (median, 74.1) and 69.4 (median, 69.7), and after surgery, they were 41.0 (median, 30.1) and 36.7 (median, 30.2) for children with OSAS and for children with mild SDB, respectively. The mean difference in total scores was 31.8 (SRM, 1.0) and 32.7 (SRM, 1.9) for children with OSAS and for children with mild SDB, respectively. The domain with the largest mean difference score was physical suffering, and the one with the smallest was for emotional distress. A comparison of mean difference in total and domain scores for the 2 groups of children was not significant. In the OSAS group, 16 children (37%) had a high OSA-18 total score preoperatively (⬎80), 15 (35%) had a moderate score (⬎60, ⬍80), and 12 (28%) had a low score (⬍60). Postoperatively, only 4 (9%) had a high score, 2
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Quality of Life after Adenotonsillectomy for SDB in . . .
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Table 1 Characteristics of the Study Population Study Population Mean age (Range) Percentage Male BMI7 Hispanic or Latino Non-Hispanic or Latino White Mean interval between pre-operative OSA-18 and Adenotonsillectomy (Days) Adenotonsillectomy and post-operative OSA-18 (Days) Mean interval between pre-operative and post-operative OSA-18 (Days) AHI (Range)
Children with OSAS (n⫽ 43)
Children with mild SDB (n ⫽ 18)
7 (3-17) 69% 23 (12-48) 51% 47% 90.7
7 (3-15) 67% 21 (12-43) 59% 39% 75.1
47.7
50.4
138.4
125.8
21 (10-46)
(5%) had a moderate score, and 37 (86%) had a low score. In the mild SDB group, 4 children (22%) had a high OSA-18 total score preoperatively, 11 (61%) had a moderate score, and 3 (17%) had a low score. Postoperatively, only 1 (6%) had a high score, 2 (11%) had a moderate score, and 15 (83%) had a low score. In the OSAS group, 39 children (91%) improved their OSA-18 total score, and 4 (9%) got worse. In the mild SDB group, 17 children (94%) improved, 1 (6%) stayed the same, and none got worse. The pattern of change in the OSA-18 survey items after surgery is illustrated graphically in Figure 1. The pattern of scores for the domains is remarkably similar before and after surgery and there is an improvement in mean score for each domain. The domain of emotional distress shows the least improvement. The total score of the survey and all domains showed a significant change after surgery both in children with OSAS and in children with mild SDB.
DISCUSSION In the present study, preoperative values for the OSA-18 total score and for most domain scores were higher for children with
3 (0.0-4.9)
OSAS than for children with mild SDB, but this difference was not significant. Improvements in quality of life measured by reductions in scores for the 5 domains of the OSA-18 postoperatively are dramatic regardless of the severity of SDB. Caregivers of children with SDB report a significant improvement in quality of life after adenotonsillectomy, regardless of the severity of the underlying disorder. The domains with the highest preoperative scores and the biggest changes after surgery were physical suffering and caregiver concerns. The domain of physical suffering asks the caregivers to rate the frequency of snoring, restless sleep, and breath-holding spells at night in their child. The domain of caregiver concerns asks about the caregiver’s worry about, and frustrations with, the child. These factors are rated highly preoperatively in children with SDB regardless of severity and respond most significantly to surgical therapy. The domains of emotional distress and daytime problems had the lowest preoperative scores and the smallest change after surgery. The domain of emotional distress asks about mood swings, aggressive and hyperactive behaviors, and temper tantrums. The domain of daytime problems asks about excessive daytime sleepiness, poor concentration, and difficulty getting out of bed
Table 2 Mean Pre- and Post-operative OSA Scores for Children with Moderate to Severe OSAS and Children with Mild SDB OSA-18 Total Score*
Children with OSAS Survey 1 Survey 2 Children with Mild SDB Survey 1 Survey 2
Children with OSAS (n⫽ 43)
Mean
95% CI
Sleep Disturbance
95% CI
Physical Suffering
95% CI
Emotional Distress
95% CI
Daytime Problems
95% CI
Caregiver Concerns
95% CI
72.8 41.0
67.3-78.5 33.6-48.4
18.7 8.4
16.8-20.5 6.5-10.3
14.6 8.9
12.8-16.3 7.3-10.4
11.5 8.4
9.9-13.2 6.9-9.9
11.4 7.4
9.8-13.0 5.9-8.9
16.5 7.8
14.5-18.4 6.0-9.6
69.4 36.7
60.2-78.6 27.1-46.2
17.6 6.8
15.0-20.2 4.8-8.8
14.4 8.2
12.1-16.6 5.5-10.8
9.5 6.8
6.9-12.1 4.7-9.0
12.2 7.4
10.1-14.3 5.1-9.8
15.7 7.4
13.0-18.4 4.8-10.0
*p-values ⬍.0001 for mean total dcores and mean domain scores of survey 1 vs. survey 2 for both groups of children.
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Otolaryngology–Head and Neck Surgery, Vol 133, No 4, October 2005 preoperative score- OSAS postoperative scores-OSAS
OSA-18 Domain scores
20.0
preoperative scores- Mild SDB postoperative scores-Mild SDB
15.0 10.0 5.0 0.0 Sleep disturbance
physical suffering
emotional distress
daytime problems
caregiver concerns
Figure 1 Pre- and postoperative OSA-187 domain scores for hcildren with OSAS and Mild SDB.
in the morning. It is interesting that the domain of daytime problems was the only domain in which the mean score for the mild SDB group was higher than for the OSAS group. Again the improvements postoperatively appear independent of the severity of SDB. Preoperatively, on the basis of the OSA-18 total score, 37% of children with OSAS and 22% of children with mild SDB had values that were consistent with a high impact on healthrelated quality of life. Postoperatively, in both groups, ⬍10% of children remained in the same group. Equally, ⬎90% of children with SDB improved their scores postoperatively regardless of the severity of SDB. It is clear that surgical therapy is associated with dramatic improvements in children’s quality of life even when the condition is mild. There is increasing evidence that mild airway obstruction evidenced by primary snoring is far from benign. Blunden et al7 showed that children with primary snoring had reduced neurocognitive performance compared with controls. This included deficits in attention, memory, and intelligence scores. Kennedy et al8 showed that children with primary snoring had reduced verbal and global IQ scores and reduced attention and memory compared with controls. O’Brien et al9 showed that children with primary snoring, in a sample of children from the community who did not seek medical intervention, had lowered neurocognitive function compared with nonsnoring children. These studies have not compared children with primary snoring with children with OSAS and have not shown that intervention with adenotonsillectomy leads to improvements in behavior. Nonetheless, they highlight the need for further studies in children with primary snoring and other forms of mild SDB. This is especially true because behavioral problems may be more prevalent in children with mild rather than severe OSAS.10 In this study, mild SDB was defined as an AHI of less than 5 and an AI of less than 1. The mean AHI for children with mild SDB was 3. This includes children with primary snoring, upper airway resistance syndrome,11 and mild OSAS. We also studied children with a sleep disturbance that was symptomatic enough to request medical intervention. This may represent a selection bias. Caregivers of children who have persistent or worsening symptoms are more likely to seek surgical therapy, and these children may benefit to a greater extent than an equivalent community sample. There are a number of other limitations to this study. We did not have a control group. We therefore can conclude that
surgical therapy for SDB is associated with an improvement in quality of life but cannot infer causality. There also are no long-term data to report. It is possible that improvements in quality of life are maintained in the long term in children with OSAS to a greater degree than in children with mild SDB.12-14 Finally, the small number of children in this study did not allow us to compare the improvements in quality of life in different age, ethnic, and body-mass index groups. In summary, preoperative values for the OSA-18 total and domain scores are high in children with either OSAS or mild SDB. Both groups of children show a dramatic improvement in quality of life after adenotonsillectomy, and the degree of improvement is similar. This suggests that even mild forms of SDB evidenced by snoring but only isolated incidents of apnea or hypopnea have a decidedly negative effect on quality of life. It also raises the possibility that mild forms of SDB may have a significantly negative impact on child behavior.7-9 Fortunately, surgical therapy with adenotonsillectomy is associated with marked improvement in quality of life for children with either mild or severe SDB.
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