What leads to the expectation to return to work? Insights from a Theory of Planned Behavior (TPB) model of future work outcomes

OBJECTIVE: This study used a Theory of Planned Behavior (TPB) model to identify the factors influencing the future work expectations and outcomes of employees with a musculoskeletal injury.

PARTICIPANTS: Australians with a compensable work injury (N=174), mean age=43.7 years, 53.2% male, 48.3% back injury , and 34.2% unskilled.

METHODS: A TPB model of the target behavior 'working, or continuing to work … three months from now' was constructed. A questionnaire measuring the model's components was completed at baseline and three-months follow-up.

RESULTS: The model met standard psychometric requirements. Attitude, Subjective Norm and Perceived Behavioral Control explained 76% of the variance in Behavioral Intention ( $R^{2}$ = 0.76, p< 0.001). Behavioral Intention (the expectation to return to work) explained 51% of the variance in work participation at follow-up (Nagelkerke $R^{2}$ =0.51, p< 0.001; sensitivity=86.4%, specificity=71.2%). The strength of key influences on expectations varied according to employment status, but included the availability of modified duties, social aspects of work, the opinion of the treating doctor, co-worker support, pain, and functional limitations.

CONCLUSION: The TPG is a useful model and conceptual framework for integrating the biopsychosocial determinants of return to work (RTW) and identifying the influences on future work expectations and outcomes.