Workplace Injury and Mental Health Outcomes.

IMPORTANCE

Workplace injury is a widespread problem that impacts mental health and quality of life and places a substantial burden on employers and the health care system.

OBJECTIVE

To determine whether mental disorder rates differ following workplace injury compared with injuries outside the workplace.

DESIGN, SETTING, AND

PARTICIPANTS

This retrospective cohort study assessed individuals hospitalized for an injury requiring surgery between January 1, 2002, and December 31, 2018, with a 2-year follow-up period using population-based administrative data in Manitoba, Canada. Analyses were completed June to July 2021. This study compared 2 cohorts: individuals with a workplace injury matched 1:5 on sex, age, geographical region, and surgical procedure code with individuals with a nonworkplace injury in the general population.

EXPOSURE: Traumatic physical injury that required surgery with anesthetic.

MAIN OUTCOMES AND MEASURES: The outcome of interest was a diagnosis of mental disorder (anxiety, depression, substance abuse, suicide attempt, and any mental disorder), measured 2 years prior to and following injury.

RESULTS

In this cohort study, 7556 individuals (mean [SD] age, 44.8 [13.3] years; 5721 [75.7%] male; 4624 individuals [61.2%] with urban residence; 4545 individuals [60.1%] with low income) with a workplace injury were compared with 28 901 matches from the general population. The workplace cohort had lower rates of all mental disorders (anxiety: adjusted rate ratio [ARR], 0.82; 95% CI, 0.77-0.87; depression: ARR, 0.78; 95% CI, 0.72-0.84; substance abuse: ARR, 0.63; 95% CI, 0.55-0.72; suicide attempt: ARR, 0.28; 95% CI, 0.11-0.70; and any mental disorder: ARR, 0.82; 95% CI, 0.78-0.86; all P < .0006) before their injury and for depression (ARR, 0.89; 95% CI, 0.82-0.95) and substance abuse (ARR, 0.83; 95% CI, 0.73-0.94) after their injury. The group × care period interaction term was significant for anxiety (P < .0001) and any mental disorder (P < .0001), suggesting that individuals with workplace injuries had worse mental disorder outcomes over time than individuals with nonworkplace injuries.

CONCLUSIONS AND RELEVANCE: This cohort study found that the mental health trajectory from the preinjury to postinjury period was worse for individuals with a workplace injury compared with those injured outside the workplace. These findings suggest that there may be features unique to the workplace and/or injury claims and compensation processes that contribute to this pattern, which warrant further examination.