Prolonged Physical Inactivity in Older Adult Couples: A Dyadic Analysis Using Actigraphy.

BACKGROUND AND OBJECTIVES: Many older adults remain inactive despite the known positive health implications of physical activity (improved mood, reduced mortality risk). Physical inactivity is an interdependent phenomenon in couples, but most research examines physical inactivity at the individual level. We estimated the average amount of prolonged physical inactivity for older adult couples and, using dyadic analysis, identified physical and mental health determinants thereof. RESEARCH DESIGN AND METHODS: Forty-six heterosexual older adult couples (age = 70.61 ± 6.56) from the Veterans Integrated Service Network 20 cohort of the Collaborative Aging Research using Technology (CART) initiative were included. The average number per day of prolonged inactive periods (no step counts or sleep activity for ≥30 min) was estimated using actigraphy data collected over a month. RESULTS: Multilevel modeling revealed that, within couples, there was no significant difference between partners in the average amount of inactive periods (p = .28). On average across couples, males and females had an average of 6.90 ± 2.02 and 6.56 ± 1.93 inactive periods per day, respectively. For males, older age was the only variable associated with more inactive periods (ß = 0.15, p = .002). For females, having more depressive symptoms in both dyad members was associated with fewer inactive periods (female: ß = -0.30, p = .03; male: ß = -0.41, p < .001), and more dependence in completing their own instrumental activities of daily living predicted more inactive periods (ß = 2.58, p < .001). DISCUSSION AND IMPLICATIONS: Viewing couples' activity as an interdependent phenomenon, rather than individual, provides a novel approach to identifying pathways to reduce inactivity in older adults, especially when focusing on the mental health and level of independence within the couple.