The study, led by Vincent Arena, Ph.D., of the University of Pittsburgh, examines the relationship between body-mass index (BMI) – a standard measure of the relative percentages of fat and muscle mass – and short-term disability (STD) in a population of white-collar workers. To learn more about that relationship, the researchers analyzed data from health-risk appraisals of more than 19,000 employees of a large financial services institution. The health-risk appraisals were filled out between 2000 and 2002.
"Our study demonstrates that workers with progressively higher BMIs experience a greater number of STD events and therefore a greater number of STD workdays lost than workers with a normal BMI," the researchers explained in the article, titled "The Impact of Body-Mass Index on Short-Term Disability in the Workplace."
After analyzing data from the health-risk appraisals and taking several risk factors – such as gender, ethnicity, hours worked, age and BMI – into account, the researchers discovered that short-term disability rates in the study population were highest among obese workers (those having a BMI of 30 or higher); 14.9 percent of obese workers went on STD leave at some point during the study period.
By comparison, 8.8 percent of overweight workers (those having a BMI of 25 to 29.9) and 7.3 percent of normal-weight workers (BMI of 18.5 to 24.9) went on STD leave during the study period.
Overall, 9.6 percent of employees had at least one episode of short-term disability during the study period.
When researchers isolated BMI as an independent and significant factor, they found that the relationship between increased body weight and short-term disability leave remained significant. Compared to normal-weight workers, obese workers' STD rates were 76 percent higher. Overweight workers' STD rates were 26 percent higher than normal-weight workers.
Women and Minorities Also Have Increased Rates
Researchers found that nearly one-third of absences due to STD leave were related to musculoskeletal conditions (such as arthritis and low back pain) or mental health conditions (such as depression).
The study also indicated that women had a higher rate of short-term disability than men. However, three-fourths of the employees in the study were women.
Rates also tended to be higher for non-exempt employees, African-American and Hispanic employees and workers from the staff and lower-level officer ranks.
Previous studies have linked obesity to increased health costs, increased absenteeism and reduced productivity. As the U.S. obesity rate continues to increase, disability rates are expected to rise as well, according to Arena.
As a result, Arena and his colleagues suggest that companies look into programs designed to promote healthier body weight among their employees.
"Successful weight management initiatives should reduce short-term disability expenditures, improve worker productivity and lessen the indirect costs associated with overweight and obesity," they concluded.