Social support, social strain, sleep quality, and actigraphic sleep characteristics: evidence from a national survey of US adults.

OBJECTIVE To determine the associations between average family and friend social support and strain over 10 years and sleep quality, sleep efficiency, total sleep time, and night-to-night total sleep time variability. PARTICIPANTS Non-institutionalized English-speaking US adults aged 34-81 who participated in the MacArthur Study on Aging: Midlife in the United States. MEASUREMENTS Sleep quality was assessed by the Pittsburgh Sleep Quality Index and by a 7-day daily diary. Sleep efficiency, total sleep time, and night-to-night total sleep time variability were assessed by actigraphy (MiniMitter 64). RESULTS Social support, but not social strain, was significantly associated with both self-reported measures of quality (social support β=-1.239, P=.019 for global Pittsburgh Sleep Quality Index scores; social support β=-0.248, P=.016 for diary assessed quality). Lower scores on both quality measures indicate better sleep. In contrast, social strain, but not social support, was significantly associated with sleep efficiency (social strain β=-3.780, P=.007). Social strain, but not social support, was significantly associated with night-to-night sleep variability (social strain β=0.421, P=.034); however, the overall model was not significant. Neither social support nor social strain was significantly associated with total sleep time. CONCLUSION Social support was significant for self-reported sleep, whereas only social strain was significantly associated with objective sleep parameters. Future research on social relationships and sleep should analyze both positive and negative aspects of relationships in tandem because effects appear to differ based on outcome.