Association between Long Work Hours and Chronic Disease Risks over a 32 Year Period

Background and Objectives:  Numerous studies have shown that working long hours is related to specific adverse health and safety outcomes.  Much of the existing evidence about the effects of long work hours has involved cardiovascular diseases.  However, similar risks for other chronic disorders may also be related to lifetime exposure to long-hour work schedules.  This study utilized national survey data to assess whether workers’ long-term exposure to extended-hour schedules creates a risk for contracting chronic diseases later in life, including heart disease, non-skin cancer, arthritis, diabetes, COPD, asthma, depression, and hypertension.

Methods:The National Longitudinal Survey of Youth, 1979 was used to create 32-year work histories (1978-2009) for 7,492 respondents.  The average weekly work hours were calculated for each week in which the employee worked full time (i.e., at least 30 hours per week).  Logistic regression analyses were performed to test the association between the average hours worked per week and the occurrence of each of the eight chronic diseases listed above, adjusting for age, gender, race, education, family income, number of years worked, smoking status, and occupation.

Results: Working long hours (e.g., 41-50, 51-60 and 60+ compared to 30-40 hours per week) was associated with a significantly elevated risk of chronic heart disease, non-skin cancer, arthritis, and diabetes.  The observed effects were larger and more significant among women than among men. 

Conclusions: Working long hours significantly increased workers’ risk of contracting specific chronic diseases.  Women might be disproportionally affected by long work hours compared to men.