Hours of work and health in Japan.

<bold>Purpose: </bold>This article aimed to examine the causal relationships of hours of work with health behaviors and health outcomes.<bold>Method: </bold>The data were derived from Japan Household Panel Survey/Keio Household Panel Survey. In total, data from 2677 men and 2170 women were analyzed to show the effects of hours of work on body mass index, smoking, and sleeping hours. To deal with the potential endogeneity of decisions about hours of work, the instrumental variable approach was used.<bold>Results: </bold>Hours of work had a negative impact on hours of sleep among men (coefficient [coef.], -0.371; 95% confidence interval [CI], -0.519 to -0.223). Longer hours of work also increased the probability of men being obese (coef., 1.108; 95% CI, 0.234-1.981) and the number of cigarettes they smoked each day (coef., 1.007; 95% CI, 0.037-1.978). For women, longer hours of work increased the probability of being obese (coef., 0.029; 95% CI, 0.009-0.050) and decreased the hours of sleep (coef., -0.416; 95% CI, -0.618 to -0.214).<bold>Conclusions: </bold>This article suggests that the health consequences of long hours of work include health behaviors and health outcomes that can lead to higher risks of morbidity and mortality. [ABSTRACT FROM AUTHOR]