Association of sleep quality and free time leisure activities in Japanese and British civil servants.

Sleep disturbance as a pervasive health problem can directly affect the physical and psychological well-being of individuals. Factors that positively relate to sleep quality can therefore improve healthy functioning. We examined whether leisure time activities are associated with sleep quality in two culturally different samples of civil servants. In this cross-sectional study we evaluated 1,682 Japanese, in Toyama prefecture (T) city, and 6,914 British civil servants from the Whitehall II study undertaken in London. The Japanese version of Pittsburgh sleep quality index (PSQI-J) was used in T city and Jenkins' sleep problem scale was used in the Whitehall II study. Setting a validated cut-off point of 5.5 for the PSQI-J global score and the upper tertile point for the Jenkins' sleep problem scale, we conducted logistic regression analysis to assess the association between leisure time activities and sleep quality. In both populations, those who participated in voluntary activities in clubs or organizations were significantly less likely to have poor sleep quality with Odds ratios (OR) and 95% confidence intervals (95%CI) of 0.73 (95%CI; 0.56-0.97) and 0.85 (95%CI; 0.76-0.95) in Japanese and British civil servants, respectively. Similar findings were apparent for visiting friends and relatives (ORs 0.60 (95%CI; 0.46-0.80) and 0.71 (95%CI; 0.56-0.90) for Japanese and British subjects, respectively). Our findings suggest that engagement in social leisure activities is associated with better sleep quality and consequently better general well-being.