Objective. Little is known about the effects of obstructive sleep apnea syndrome (OSAS) on utilization of health care services in children. The present study compares medical service utilization by children with OSAS with that of healthy children.
Methods. A cross-sectional study of 287 consecutively recruited children (1–18 years) with OSAS and no concomitant diseases and a control group matched by age, gender, and geographic location was conducted at the Clalit Health Care Services clinic in the southern region of Israel. Children in the study group underwent nocturnal polysomnography (PSG) studies. The control group (N = 1149) was randomly selected from the Clalit Health Care Services database. PSG was performed for the OSAS patients. Indices of health care utilization 1 year before the PSG study were analyzed.
Results. A 226% increase in health care utilization was noted among children with OSAS. Children up to 5 years of age consumed more health care resources than children over 5 years. Children with OSAS consumed more health care services than the control group at all ages. The leading components of this high cost are utilization of more hospital days, drugs, and visits to the emergency department. The severity of the OSAS correlates directly to total annual costs and independently to age (β = 0.19).
Conclusions. Children with OSAS are heavy consumers of health care services 1 year before any specific evaluation and treatment for apnea. Early diagnosis and intervention may be cost-effective.
Obstructive sleep apnea syndrome (OSAS) in children may be associated with recurrent respiratory tract infections, growth failure, cor pulmonale, secondary enuresis, behavioral and neurocognitive problems, growth retardation, and poor school achievement.1–6 The prevalence of OSAS in children is estimated to be 1% to 2%.1,7 The most common cause of OSAS in children is adenotonsillar hypertrophy; adenotonsillectomy (T&A) is the treatment of choice.8
Recent evidence9–11 demonstrated that adults with OSAS are massive consumers of health care services, including higher admission rates and longer lengths of stay in hospitals,12 with a 2- to 3.5-fold increase compared with healthy subjects years before their apnea is diagnosed in sleep laboratories. This elevation of health care consumption was related to cardiovascular morbidity, obesity, and, most likely, risk factors that predispose to OSAS, such as alcohol use, caffeine, and tobacco use.9,12 Adequate treatment by continuous positive airway pressure, which is the treatment of choice, reduces health care utilization11–13 and improves quality-adjusted life years.14
A recent state-of-the-art publication on sleep disorder breathing in children1 did not emphasize the effect of OSAS on the health care system. We hypothesized that because of the associated morbidity, health care utilization by these children would be higher. In the present study, we compared the utilization of medical resources of children with OSAS to a matched healthy control group.
All children are members of Clalit Health Care Services (CHS), the largest health maintenance organization in Israel. All children who participated in the study were from the Negev, the southern region of Israel. This region includes approximately 450 000 CHS enrollees, 20% of whom are of Bedouin origin. All families of included children had been permanent residents of the region for at least 3 years before study initiation.
We compared health care utilization between “typical” OSAS and control patients. We excluded children who exhibited extreme consumption of health care services, ie, >10 times the mean values of their group. This excluded 3 children from the OSAS group and none from the control group.
The study group included all children who were ages 1 to 18 years and referred to the Sleep-Wake Disorder Unit in the Soroka University Medical Center in Beer-Sheva for evaluation of OSAS. Children were recruited consecutively during the period of August 1998 through August 2000. We excluded children younger than 1 year and those with additional chronic morbidity.
The control group was matched to the OSAS group by age, gender, and area of residence (to adjust for socioeconomic factors). Four control subjects with no documentation for concomitant chronic disease were randomly selected for each OSAS patient (using Microsoft Access; Microsoft Corp, Redmond, WA) from the regional CHS database (containing 126 357 enrollees). We confirmed that the control group was healthy by verifying that they did not receive any long-term medication.
The Sleep-Wake Disorder Unit in the Soroka University Medical Center is the only such center for children in the Negev. All children underwent nocturnal polysomnographic (PSG) monitoring (SensorMedics Inc, Yorba Linda, CA).15
Subjects reported to the sleep laboratory at 8:30 pm and were discharged at 7:30 am the next morning. They were encouraged to maintain their usual daily routine and take medications as usual.
Overnight PSG monitoring was performed as follows. Two silver-silverchloride electroencephalogram (EEG) electrodes filled with electrolyte were applied to the C3 and C4 locations, and reference electrodes were attached behind the ears in the left (A1) and right (A2) mastoid areas. Two electromyographic electrodes were applied over the submental muscles. Two electro-oculographic electrodes were applied 1 cm above the outer canthus of 1 eye and 1 cm below the outer canthus of the other eye. The montage arrangement for PSG reading consisted of C3A2 and O2A1, 2 electro-oculographic, and electrocardiogram (modified V2 lead). Nasal airflow was monitored by a pressure transducer (RespSponse; Synectics Sleep Inc, Stockholm, Sweden); thoracic and abdominal movements were monitored by strain gauge electrodes; and hemoglobin oxygen saturation was monitored by pulse oximetry (Ohmeda 4700, Madison, WI). Sleep/wake sleep stages,16 arousals, and awakenings were scored as recommended with the appropriate modifications for children,3,17,18 and obstructive apneic and hypopneic events7 were recorded.
Health Care Utilization
The CHS billing system records >95% of all medical expenditures of the health maintenance organization. All costs were collected for each child in the 12-month period before the PSG evaluation. The costs of the PSG, as well as direct or indirect costs resulting from the PSG study, were not included in the study.
Cost indicators include 1) number of hospitalization days, number of pediatric “day hospital” visits (<24-hour admission), and number of emergency department (ED) visits; 2) number of (new and repeated) visits to the primary care physician and specialist; 3) drugs prescribed (type and cost for each drug; all prescribed drugs are categorized according to World Health Organization recommendation19); and 4) diagnostic tests. We defined “total annual cost” as the sum of the costs for all indicators. Costs are expressed as the mean per patient per year in US dollars according to the price list published by the Israeli Ministry of Health. The exchange rate was NIS4.1 per 1 US dollar. Values were adjusted for inflation.
Cost data were analyzed according to previously reported recommendations20 using SPSS software (SPSS, Inc, Chicago, IL). Population t test was used to determine differences in respiratory and sleep parameters between children ≥5 years and >5 years. χ2 test was used to confirm “population match” between the control and OSAS population in relation to gender and age. Two-way analysis of variance was used to determine the significance of total annual costs in children ≥5 and >5 years in the OSAS and control populations. Stepwise multiple linear regression tests were performed to analyze the effects of respiratory disturbances index (RDI), age, and arousal index on total annual costs. Mann-Whitney test was used to determine statistical significance of cost elements. Data were presented as mean ± standard deviation for all sleep parameters (Table 1) and as mean ± standard error of the mean (SEM) for costs; statistical significance was accepted when P ≥ .05. The Ethics Committee of Ben-Gurion University of the Negev approved this study.
A total of 287 children with a mean age of 5.7 ± 3.7 years (male/female: 106/186) were referred for PSG evaluation. We excluded 50 children who had known comorbidity. The control population included 1149 children matched (χ2 test) for age and gender (mean age: 5.7 ± 3.5 years; male/female: 426/726).
The OSAS population (Table 1) had an average RDI of 7.9 ± 9.5 events/h, compatible with OSAS of moderate severity.21 RDI was higher (P < .05) in children up to age 5. As expected, RDI during rapid eye movement sleep was higher. As a group, children with OSAS did not present evidence of significant nocturnal hypoxemia but demonstrated a significantly higher number of arousals. RDI severity was comparable between boys and girls.
Health Care Utilization
Health care utilization (Fig 1) among the OSAS population was 226% (P < .001) higher than in the control population. Table 2 summarizes the mean cost elements per patient per year before the PSG study. Patients with OSAS had an average of 0.1 new admissions per year compared with 0.06 new admissions (P < .05) in the control group. Mean number of hospitalization days was also higher in the OSAS population compared with control (0.23 vs 0.16 days, respectively; P < .05). Number of pediatric day hospital visits in the OSAS group was considerably higher as compared with the control group (0.06 vs 0.03 days; P < .05). However, no differences in cost per day were found in pediatric day hospital visits between the 2 groups.
Children with OSAS had considerably more visits to the ED compared with the control group (0.54 vs 0.24 days, respectively; P < .05). The OSAS group needed more consultations (≥2 visits) than the control group (67% vs 19%; P < .05).
Common consultations in the OSAS group included ears, nose, and throat surgeons for 210 children (69.7%), pediatric pulmonologists for 43 children (15%), and ophthalmologists for 43 children (15%). Other consultations included neurologists, cardiologists, dermatologists, and orthopedic surgeons (<27 children [<10%] for each specialty). The control population had significantly lower visit rates to specialists: 138 children (12%) to ears, nose, and throat surgeons, and 103 children (9%) to ophthalmologists; all other specialists had 1% to 5% referrals per specialty.
The main diagnostic tests for OSAS patients included facial sinus radiographs in 147 children (51%), chest radiographs in 44 children (15%), hearing tests in 32 children (11%), tympanometry in 15 children (5%), and EEG in 12 children (4%). The control group had chest radiographs in 59 children (5%), radiograph of the facial sinuses in 32 children (3%), audiometry in 25 children (2%), tympanometry in 12 children (1%), and EEG in 7 children (0.6%). The cost of imaging and diagnostic tests for children with OSAS was significantly higher as compared with the controls (P < .001).
The following pharmacological groups accounted for 80% of the cost for prescribed drugs: respiratory system drugs (4.6-fold greater in the OSAS group [P < .05]); general anti-infective drugs for systemic use (2.4-fold greater in the OSAS group [P < .05]); dermatologicals (2.1-fold greater in the OSAS group [P < .05]), and various other drugs (14.6-fold greater in the OSAS group [P < .05]). The cost of the prescribed drugs was 301% (P < .0001) higher in the OSAS group compared with the control group (Table 2).
An analysis of distribution of RDI and total annual cost according to the number of subjects, by year of life, is presented in Table 3. A total of 236 of the 287 children (82%) with OSAS included in the present study were in the 1- to 8-year-old age range. Between 2 and 7 years of age, the distribution of the number of children who underwent PSG study was roughly the same. OSAS severity according to RDI was the same for this age range. There was a significant linear correlation between the age of the children and total annual costs for both the OSAS and control groups (β = −0.23, P < .002). However, the OSAS group had significantly higher costs (P < .001) compared with the control group, for all ages in the 1- to 8-year-old range (Table 3).
Costs, Age, Ethnicity, and RDI
The leading elements of cost that explain the differences between children ≥5 years compared with children >5 years are summarized in Table 4. In both groups, we found that children ≥5 years consume more health care resources (P < .001, 2-way analysis of variance) compared with children >5 years (Fig 2). Children ≥5 years had more hospitalization days, had more visits to the ED, and received more prescriptions for more drugs.
Total annual costs for the entire OSAS population was found to correlate with age but not with ethnic group or arousal index. Additional analysis (Table 5) by a split multiple stepwise multiple linear regression (children up to and above the age of 5 years) revealed that OSAS severity, as calculated by RDI but not arousal index, correlated independently to the total annual costs only for children ≥5 years. For children >5 years, no correlation was found between total annual cost and RDI or arousal index.
In the present study, we demonstrated that children with OSAS are heavy consumers of health care resources. The main elements that affect this high consumption of health services are hospitalization rates, visits to the ED, and specialists and drugs issued. Children who are ≥5 years and have OSAS are higher consumers of health care services than are children who are >5 years and the control group. In children ≥5 years, RDI correlated to the total annual costs.
Several lines of evidence support our premise that the information presented in this study reflects the “true” consumption of health care resources of children with OSAS. First, all PSG and the relevant medical information regarding OSAS patients are stored in the only Sleep-Wake Disorder Center in the study region. Second, CHS uses 1 billing system located in the regional Department of Health Economics. Third, equal access to medical services is provided to all children according to the national health care law implemented in January 1995. Finally, physicians are paid a capitation fee once every 3 months per patient and therefore do not have any economic incentive to increase consumption of services.
Our data may be difficult to compare with those from other health care systems that have more than 1 payer. We believe that our data can be compared with recently published9–11 reports from Manitoba, Canada, where they demonstrated higher health care service utilization in adults with OSAS.
The present study demonstrates results for “typical” children with OSAS because we excluded 3 children who showed a 10-fold increase in health care utilization. The control population was matched by age, gender, and settlement location (to control for socioeconomic factors); thus, we compared patients matched to general population controls. The control group was selected randomly from a database containing information about chronic diseases and/or prescribing medications for chronic conditions. We do not have medical information on the control group. It is possible that 1% to 2% of the control population might have undiagnosed OSAS. With this in mind, our control population was 4 times larger than the group with OSAS.
Health care utilization in adults with OSAS is related to risk factors that predispose to OSAS, such as obesity, alcohol use, caffeine and tobacco consumption, and comorbidity, eg, cardiovascular complications and hypertension.9,12 In the current study, the elevation of health care consumption is most likely related to the associated morbidity in children with OSAS. We assume that recurrent respiratory tract infections were the main problem, but additional investigation of the patient complaints that led to ED visits is required. Our database for the present study did not include this type of information.
This study was designed to compare the cost of medical services for children with OSAS with matched controls. Several findings within the patient group warrant elaboration. We found that children ≥5 years have more severe OSAS (higher RDI) than children >5 years. This can be explained by the fact that occurrence of adenotonsillar hypertrophy peaks between ages 3 and 6.1,22 In addition, in children ≥5 years, health care utilization was maximal. The main factors in elevated total annual costs in children who are ≥5 years and have OSAS are inpatient admissions and visits to the ED. These 2 cost indicators may reflect severe morbidity, are mainly induced by physicians, and can serve as “objective” indicators to identify patients with high morbidity. Inpatient admissions, visits to the ED, and prescription drugs represent 50% of total annual costs of OSAS patients. It is interesting that the amount of sleep fragmentation (high number of arousals) does not affect costs. Additional research is planned to identify information in the medical diagnoses that influence admissions, visits to the ED, and drug consumption by children with OSAS.
Preliminary results from our laboratory on 70 children who had OSAS and underwent T&A revealed a 20% decrease (P < .05) in total annual cost within the following year.23 These results are part of an ongoing study on children who underwent T&A. This study will follow children for up to 3 years to investigate the effect of intervention on costs and quality of life. OSAS is a chronic condition in children and adults. Chronic disorders consume most of the health care resources; therefore, decision makers should prioritize early OSAS diagnosis and treatment.14,24 A better understanding of OSAS in children may necessitate a change in our approach to treatment, for example, defining better timing for PSG evaluation and T&A. This in turn may provide better medical and cost outcomes.
We found that children with OSAS are heavy consumers of health care services 1 year before PSG evaluation. The consumption of health care services was greater in children ≥5 years and in direct correlation to the severity of OSAS. Additional research is needed to determine the proper timing for diagnosis and intervention relative to quality of life and cost-effectiveness.
- Received September 4, 2001.
- Accepted January 8, 2002.
- Address correspondence to Ariel Tarasiuk, PhD, Department of Physiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Box 105, Beer-Sheva 84105, Israel. Email:
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- Copyright © 2002 by the American Academy of Pediatrics