Reciprocal associations between depression, anxiety and work-related injury.

Objective: To examine the reciprocal longitudinal associations between depression or anxiety with work-related injury (WRI) at a large employer in the southwestern United States.

Method: Three administrative datasets (2011-2013) were merged: employee eligibility, medical and prescription claims, and workers' compensation claims. The sample contained 69 066 active employees. Depression and anxiety were defined as episodes of medical visits care (ie, claims) with corresponding ICD-9-CM codes. For an individual's consecutive claims, a new case of depression or anxiety was defined if more than 8 weeks have passed since the prior episode. The presence of a workers' compensation injury claim was used to identify WRI. Three-wave (health plan years 2011 or T1, 2012 or T2, and 2013 or T3) autoregressive cross-lagged models were used to estimate whether depression or anxiety predicted WRI, also if WRI predicted depression or anxiety in the following year(s).

Results: Depression predicted injury from T1 to T2 (β=0.127, p<0.001) and from T2 to T3 (β=0.092, p=0.001). Injury predicted depression from T1 to T3 (β=0.418, p<0.001). Effects of anxiety on WRI were small and inconsistent, from T1 to T2 (β=0.013, p=0.622) and from T2 to T3 (β=-0.043, p=0.031). T1 injury had a protective effect on T3 anxiety (β=-0.273, p<0.001).

Conclusions: We found evidence of reciprocal effects for depression with WRI after adjustment for prior injuries and depression. The evidence for the relationship between anxiety and WRI is less clear. WRI prevention and management programmes should incorporate depression prevention and management.