Self-reported nap behavior and polysomnography at home in midlife women with and without insomnia

Study Objectives: To describe self-reported nap behavior and relationships among nap history, nap behavior during the study, indicators of subjective and objective insomnia, and self-reported daytime sleepiness from data prev iously obtained in a week-long field study of sleep in midlife women with a nd without insomnia. Design: Descriptive/comparative secondary analysis. Setting: Individual homes of the participants. Participants: Midlife women (mean age 46 +/-4 years) with self-reported ins omnia (n=101) and women with adequate sleep (n=30). Interventions: N/A Measurements and Results: Sleep patterns were assessed by polysomnography ( PSG), daily diaries, and a sleep history form. Although all women were requ ested not to nap, 47% of the women reported nap behavior during the study. Strong relationships were observed between a history of daytime naps and na p behavior (chi (2)=25.63, p less than or equal to .001), and a history of feeling sleepy or struggling to stay awake during the daytime (i.e., sleepi ness) and nap behavior (chi (2)=18.05, p less than or equal to .001) during the study. There was also a modest significant (p less than or equal to 05 ) correlation (r=. 25) between tiredness and nap duration during the study. There were no statistical differences in sleep variables between the nappi ng and non-napping groups. In the napping group, there were no differences between women with sleep efficiency < 85% (objective insomnia) and those wi th sleep efficiency > 85%. Conclusions: Habitual nap behavior may be indicative of daytime sleepiness in women with insomnia, but it is not necessarily related to subjective or objective measures of insomnia. Women who routinely nap may be unable to re frain from napping during the daytime in long-term research studies.