Is insomnia an independent predictor of obstructive sleep apnea?

Introduction: obstructive sleep apnea (osa) is a disorder with high prevalence in primary care. however,little research exists on screening for osa in primary care samples. methods: one hundred family medicine patients completed standardized symptom and demographic questionnaires and a structured clinical interview for sleep disorders. two-step logistic regression was performed to determine the independent predictive value of insomnia for clinical identification of osa. additional t tests were computed to examine age and sex patterns of insomnia. results: a model including body mass index and daytime sleepiness predicted osa status (χ 2 = 18.63; p < .001) and explained 27% of the variance in osa clinical diagnosis. addition of insomnia scores to the model significantly improved predictive utility (χ 2 = 25.79; p < .001) and explained 36% of the variance in osa. insomnia scores were higher for women compared with men (p = .033) and women with osa compared with women without osa (p = .007). conclusions: inquiry regarding insomnia may improve clinical identification of osa when screening for osa in primary care. this finding possibly is unique to the evaluation of osa in a primary care versus sleep laboratory sample. the predictive utility of insomnia may be specific to women.