Similarities and differences in estimates of sleep duration by polysomnography, actigraphy, diary, and self-reported habitual sleep in a community sample.

OBJECTIVES

To compare estimates of sleep duration defined by polysomnography (PSG), actigraphy, daily diary, and retrospective questionnaire and to identify characteristics associated with differences between measures.

DESIGN

Cross-sectional.

SETTING

Community sample.

PARTICIPANTS

The sample consisted of 223 Black, White, and Asian middle- to older-aged men and women residing in the Pittsburgh, PA area.

INTERVENTIONS: Not applicable.

MEASUREMENTS: Two nights of in-home PSG; 9 nights of wrist actigraphy and sleep diaries; retrospective sleep questionnaires; and measures of sociodemographic, psychosocial, and adiposity characteristics.

RESULTS

All measures of sleep duration differed significantly, with modest associations between PSG-assessed and retrospective questionnaire-assessed sleep duration. Individuals estimated their habitual sleep duration about 20-30 minutes longer by questionnaire and their prospective sleep diaries compared with both PSG- and actigraphy-assessed sleep duration. Persons reporting higher hostility had smaller associations between PSG-assessed sleep duration and other methods compared with those with lower hostility; those reporting more depressive symptoms and poorer overall health had smaller associations between actigraphy-assessed sleep duration and questionnaire and diary measures. Apnea-hypopnea index was not related to differences among estimates of sleep duration.

CONCLUSIONS

PSG, actigraphy, diary, and retrospective questionnaire assessments yield different estimates of sleep duration. Hostility, depressive symptoms, and perceptions of poor health were associated with the magnitude of differences among some estimates. These findings may be useful in understanding the health consequences of short or long self-reported sleep duration and for guiding investigator decisions about choices of measures in specific populations.