The Identification of a Long Work Hours Threshold for Predicting Elevated Risks of Adverse Health Outcomes.

Abstract Working long hours has been associated with adverse health outcomes; however, a definition of long work hours relative to adverse health risk has not been established. Repeated work hour measures among ~2,000 participants from the Panel Study of Income Dynamics (1986-2011) were retrospectively analyzed to derive statistically optimized cut points of long work hours that best predicted three health outcomes. Work hours cut points were assessed for model fit, calibration, and discrimination separately for the outcomes of poor self-reported general health, incident cardiovascular disease, and incident cancer. For each outcome, the work hour threshold that best predicted increased risk was 52 hours per week or more for a minimum of 10 years. Workers exposed at this level had a higher risk of poor self-reported general health (RR = 1.28; 95% CI: 1.06, 1.53), cardiovascular disease (RR = 1.42; 95% CI: 1.24, 1.63), and cancer (RR = 1.62; 95% CI: 1.22, 2.17) compared to those working 35 to 51 hours per week for the same duration. This study provides the first health risk based definition of long work hours. Further examination of the predictive power of this cut point on other health outcomes and in other study populations is needed.