This study examined the association between sleep-disordered breathing and childhood behavior problems among a group of inner-city children with asthma. We found that one third of urban children with asthma may be suffering from SDB. This is considerably higher than the current estimates of SDB in children, and suggests that routine screening for SDB might be particularly important for children with asthma. Similarly, we found that 32% of these children have behavioral symptoms severe enough to warrant further evaluation. It is clear from these findings that urban children with asthma are at risk for both SDB and poor behavior.
Children with asthma and sleep-disordered breathing had worse behavior compared to children without sleep difficulties. Children with SDB scored nearly 5 points higher on the total BPI compared to children without SDB. This means that children with SDB exhibited, on average, 5 more problem behaviors than children without sleep difficulties. These findings were particularly prominent in the externalizing domains, including hyperactivity and headstrong behaviors, and remained even when controlling for important variables which can influence children’s sleep, behavior, and parent’s report of sleep and behavior.
Prior research has also demonstrated a relationship between sleep disturbances and externalizing behavior problems. For example, a recently published study of children with a clinical diagnosis of SDB compared children’s scores on the SRBD scale (excluding the 6 attention/hyperactivity questions) with their behaviors before and after adenotonsillectomy.30
The authors reported a strong association between children’s sleep scores and inattention, oppositional behaviors, and an attention deficit and hyperactivity disorder index prior to surgery, with some suggestion of improvement after surgery. Another study found similar results among a large population based sample of children, where symptoms of SDB were present in 25% of children,25
and these children were more likely to exhibit problem behaviors such as hyperactivity, inattention and aggressive behaviors.
A strength of our study is that we were able to account for many possible confounding variables in our analyses, which is noteworthy since the etiology of poor childhood sleep is complex. For example, African American children, children that are overweight or obese, and children who were born prematurely have been found to be at an increased risk for SDB.20,47,48
Furthermore, mental distress of parents has also been associated with poor child sleep.49,50
Similarly, behavior problems are more prevalent among poor and urban populations.51
Social and environmental stressors such as socioeconomic status, familial issues, and environment can influence both asthma and behavioral outcomes.52
Our study is unique in that it explores the relationship between sleep and behavior among a non-referred, community-based sample of children, using previously validated surveys. Much of the literature assessing sleep and behavior has included children from clinical practices for sleep assessment, behavioral assessment or adenotonsillectomy.32
Our study observes the association between sleep and behavior among a group of non-referred, urban children with asthma, a population that could potentially benefit substantially from assessment and intervention.
Lastly, BPI and SDB surveys used in our study are brief and could be utilized in a clinical setting to help identify children with poor sleep or troubled behavior. Several studies have utilized the BPI as a parent-report measure to assess behavioral problems in children.15, 53, 54
In addition, the use of the SRBD scale in research as a way to identify children with sleep-disordered breathing is increasingly common.30, 39, 55
There are some limitations to this study. First, this is a cross-sectional study and therefore, we cannot establish a directional relationship between SDB and behavior problems in this sample of children. Additionally, behavior problems were assessed by caregiver only and were not confirmed with physicians, teachers, or with subsequent assessments. Similarly, sleep-disordered breathing was not confirmed with polysomnography, the current standard for diagnosis of SDB. However, recent studies have found a strong correlation between a sleep score of >.33 and a diagnosis of SDB using polysomnography.30, 39
In addition, we did not have information regarding prior surgeries including tonsillectomy or adenoidectomy.
All families were recruited from an inner-city community and many of these families experience stressful lives that may contribute to parents’ report of both sleep and behavior problems. Fortunately, we are able to control for several factors including parent depression, stress and quality of life in our multiple regression analysis. In addition, this study uses data at the end of a 7–9 month asthma intervention, and while we were able to control for the influence of the intervention in our models, we realize that caregivers may respond differently to questions depending on their views of the intervention.
Lastly, it is possible that parents may confuse some symptoms of sleep-disordered breathing with nighttime asthma symptoms. For example, symptoms such as ‘struggling to breathe’ or ‘intermittent breathing’ at night could be interpreted as either asthma symptoms or SDB. However, symptoms of snoring are less likely to be confused with symptoms of asthma, and when we repeated our analysis using the individual subscales (snoring and sleepiness) we found similar, consistent relationships between SDB and behavior.
Childhood sleep disorders are often overlooked in the clinical setting, and this study identifies a group of children who may be at particularly high risk. In 2002, the American Academy of Pediatrics recommended that physicians screen all children for snoring to determine risk of OSA.56
This recommendation underscores the importance of sleep disorders and children’s health. The findings of this study suggest that clinicians should be particularly diligent about screening all children with asthma for SDB, and consider sleep disorders as a possible risk factor for behavior problems. Further investigation is needed to determine whether treatment of sleep disorders would help to decrease behavior problems in this population.