Weight Change One Year After Occupational Back Injury in Washington State

Back pain is the costliest and most prevalent occupational disorder in the United States, resulting in 101,800,000 annual lost work-days. BMI and weight affect worker injury rates, productivity, claims costs, and quality of life; however, little is known about the impacts of occupational back injury on workers' weight over time. The Washington Workers' Compensation Disability Risk Identification Study Cohort (D-RISC) is a large, population-based sample of workers with back injury claims between 2004 and 2006 with at least 4 days missed from work. In addition to administrative data and medical records, workers were contacted for baseline and 1-year follow-up interviews, including self-reported weight and height. Initial descriptive results indicate that approximately 1,269 (of 1,319 who completed both interviews) workers self-reported weight measures at both interviews. More than a third of injured workers (441, or 34.8%) reported clinically significant weight change (at least 5% of baseline weight) after 1 year. Overall, 616 workers reported any weight gain (48.5%) while 448 (35.3%) reported weight loss. Among injured workers that were not working at 1 year (n=390), weight change had increased significantly using a paired t-test (3.03 lbs, p-value 0.006), while there was no significant change among workers that had returned to work (n=879, 0.21 lbs, p-value 0.64). We will build predictive models for clinically significant BMI and weight change following occupational back injury. A predictive model may be useful in identifying workers that may benefit from additional resources aimed at preventing significant weight gain after injury through population-based prevention interventions.