Predictors and measures of return to work


The National Institute for Occupational Safety and Health (NIOSH) sponsored a project for the development of a summary of the current knowledge of the predictors and measures of return to work after work-related injury or illness.


The project addressed the following questions:

    What are the primary factors that affect whether workers will return to work for their pre-injury employers, the time lost from work after the injury, subsequent employment spells, and changes in occupation?

    What are the critical data and research needs in this area?

    This project was a collaborative effort by researchers from different disciplines.


The project has been completed.

A report entitled "Determinants of Return to Work and Duration of Disability After Work-Related Injury and Illness: Developing a Research Agenda" was presented at the annual conference of NIOSH held June 13-15, 1999 in Denver, Colorado. The conference addressed performance measures for health services delivered to prevent or treat occupational injury or illness, measures of the economic and social impact of occupational injury or illness, and research that integrates these areas.


Multifactorial nature of disability and return to work (RTW)

Work disability and RTW are processes influenced by a variety of social, psychological, medico-legal, and economic factors and thus cannot be understood in biomedical or economic terms alone. About 80 different determinants of RTW outcomes were identified in this review. Future research needs to be interdisciplinary and develop a comprehensive conceptual framework to integrate this knowledge. The report suggests four criteria for prioritizing research in specific risk factor domains: risk factors under study are (1) amenable to change, (2) relevant to the users of research, (3) generalizable across health conditions, disability phases, and settings, and (4) "promising" based on qualitative explorative studies. For example, availability of modified work is a research subject which meets all four criteria. Additional research is needed to improve measurement instruments for both risk factors and outcomes.

Phase-specificity of risk factors and intervention programs

"Phase specificity" refers to the fact that the impact of risk factors (or interventions for that matter) varies across different phases of the disablement process. Some influences on RTW occur only some time after the injury (e.g., litigation), change during the course of disability (e.g., mental health), or may exert a different impact at different phases (e.g., treatment regimes for acute versus chronic pain). The right timing of intervention programs in terms of time after the injury can be decisive for the effectiveness of the program. It is necessary to use appropriate study design and analytic techniques to handle these complexities.

Selection of appropriate outcomes and databases in RTW research.

More researchers suggest combining primary data from injured worker and stakeholder interviews with secondary administrative databases. Such combined databases enrich our understanding of the full range of risk factors for delayed RTW, as well as the full burden on health, social and economic consequences of occupational illness and injury.

Further information

Determinants of return to work and duration of disability after work-related injury or illness: Developing a research agenda (publication pending)