This study is one of the first to examine comprehensively the prevalence of diagnosed sleep disorders, on the basis of ICD-9 codes, in a large, pediatric, primary care network. Surprisingly, only 3.7% of pediatric patients were given a sleep disorder diagnosis, which is significantly lower than previous reports of sleep disorders in youth. Preschool-aged and school-aged children were more likely to receive a sleep disorder diagnosis than were patients in other age groups, with household income (determined on the basis of Census data), growth parameters (head circumference and BMI), and comorbid developmental disorders (ASDs and ADHD) also being related to whether a patient received a sleep disorder diagnosis.
The low overall prevalence rates found in this study may be attributable to a combination of factors, including primary care providers not asking about sleep and parents not reporting significant sleep problems. The standard review of systems covered in well-child visits often does not include an assessment of sleep. Even if providers inquire about sleep, however, studies have shown a significant lack of education regarding sleep medicine for physicians (with even less education regarding pediatric sleep medicine).9,34–37
Some providers may be reluctant to ask much about sleep, given their lack of confidence in their ability to manage identified sleep issues.9
Overall, the sleep disorder diagnosed most commonly by the health care providers was SD-NOS. It is not clear what symptoms or concerns led to this diagnosis, and they likely varied widely among practitioners, but it has been postulated that this diagnosis includes more-benign sleep disturbances, such as sleep fragmentation and difficulties falling asleep or staying asleep. In prevalence surveys based on parental reports, the sleep problems identified most commonly included bedtime resistance and night waking,4,16,38
which may be consistent with the use of this diagnostic code by health care providers.
The other 2 sleep disorders diagnosed most commonly were SDB and enuresis. The relatively high rate of SDB diagnoses (compared with other diagnoses) likely is a result of the American Academy of Pediatrics recommendation that all children should be screened for snoring.39
However, the overall rate of combined SDB diagnoses we found in this study (~1%) is still below the overall prevalence rates of 1% to 3% for OSA and 5% to 27% for snoring.11–14
The relatively high rate of enuresis is potentially attributable to the significant impact on family and social functioning. However, consistent with the overall findings, the diagnosis of enuresis was still well below known prevalence rates.
One potential explanation for the low prevalence rates for all sleep disorders is that all medical and psychiatric diagnoses are underdocumented, but this does not seem to be the case. We also assessed the prevalence rates of diagnosed ADHD, ASDs, asthma, and type 1 diabetes, comparing the rates for our sample with national rates. ADHD was diagnosed for 4.2% of the children in our sample, which is comparable to rates in epidemiological studies (3%–8%).40
Interestingly, children in the present study were more likely to have documented ASDs (0.9%), compared with national prevalence rates (0.67%).41
For asthma and type 1 diabetes, we found prevalence rates in our sample (asthma, 14.5%; type 1 diabetes, 0.21%) similar to national prevalence rates (asthma, 13.5%; type 1 diabetes, 0.17%–0.25%).42,43
Therefore, it is unlikely that the low prevalence rates of diagnosed sleep disorders that we saw resulted from a general lack of documentation; rather, the findings were specific to sleep disorders.
An interesting finding in this study was the relationship between income levels and diagnosis rates. Overall, children from lower-income families were more likely to be diagnosed as having a sleep disorder, starting at preschool age. This relationship may be compounded by race and ethnicity. Previous studies found that black children were at increased risk for SDB and sleep deprivation.14
Therefore, it is possible that health care providers are more likely to consider sleep disturbances in lower-income and/or ethnic minority families, with sleep issues being missed in other families. Finally, it is possible that the types of sleep problems experienced by children differ across the social strata, with diagnosable sleep disorders such as SDB being experienced more in lower-income families and behaviorally based sleep problems (that may not result in a formal diagnosis) being of greater concern in upper-income families. As we begin to evaluate sleep complaints further, as recorded in the medical records, we should be able to address these issues.
A second interesting risk factor that increased the rates of diagnosed sleep disorders involved growth parameters. In infancy, head circumference was associated with increased risk for a sleep disorder diagnosis. Prematurity, for which data were not available, is likely associated with microcephaly, whereas both microcephaly and macrocephaly may be related to neurologic and developmental concerns,44,45
all of which may result in increased risks for apnea of infancy and other sleep disturbances. For older children, BMI was a risk factor for all sleep disorder diagnoses. Clearly, SDB is related to the increasing rates of obesity, especially in adolescents. Studies indicated that obesity is associated not only with SDB but also with short sleep duration,46–48
which might have contributed to the increased rate of diagnosis of SD-NOS.
Although there are no Food and Drug Administration-approved medications for sleep in youth, the rates of medications potentially used to treat sleep problems are similar to reports of sleep medications used by pediatricians and pediatric psychiatrists and during pediatric hospitalizations.26,29,49–51
It is important to note that, although the proxy method used in this study was based on the paradigm used in previous studies, the current study results may overestimate the use of medications recommended for sleep problems.27,29
This study has several strengths, including the use of a large, representative population of youths and the examination of demographic, growth, and medical factors related to the diagnosis of pediatric sleep disorders. However, there are several limitations that should be noted. First, the use of diagnostic codes precluded identification of “sleep problems” such as bedtime problems/night waking for young children or difficulty waking up for adolescents. Although sleep problems may explain why SD-NOS was the most-common diagnosis, the rates are still far below those in previous reports. Second, sleep problems might have been discussed during the well-child visit but deemed not significant enough to warrant a diagnosis. Third, although we used an approach to the identification of potential sleep medications similar to that used in previous studies, this proxy method may overestimate the use of medications prescribed for sleep disorders. However, the rates also may be underestimates; for example, use of diphenhydramine, which can be obtained without a prescription and is the most-commonly reported medication recommended for the treatment of pediatric insomnia, would not be captured in these records.
Identified future directions include an additional analysis of sleep complaints, which are provided as text within the electronic medical records. This should help elucidate whether sleep problems are being discussed and noted even if diagnoses are not being given. A review of treatment recommendations from text in the electronic medical records would provide additional information on the care of sleep disorders in pediatric practices. Finally, additional research needs to be conducted within the pediatric community regarding reasons for the low rates of documented sleep-related disorders.
The results of this population-based study highlight the need for increased awareness of pediatric sleep disorders, including additional education for health care providers regarding the diagnosis and treatment of pediatric sleep disorders. Education about the importance of sleep is needed for parents and youths of all ages. Because youths spend more than one-third of their lives sleeping, more information about this part of a child’s day needs to become a standard dialogue topic for primary care well-child visits, which would likely result in sleep disorders becoming more widely recognized and treated.