PRODISQ: a modular questionnaire on productivity and disease for economic evaluation studies.

Productivity costs are often an important cost component in economic evaluations of healthcare programs. However, there still remains a low degree of consensus on the exact measurement and valuation of these productivity costs. The development and testing of valid measurement instruments in patient and worker populations may give researchers better tools to perform economic evaluations. This review briefly reports on the development, testing and validity of the modular PROductivity and DISease Questionnaire (PRODISQ) for the measurement (and valuation) of productivity costs. It was tested in several Dutch samples of patients and workers. The modular questionnaire covers all relevant aspects of the relationship between health and productivity including absence from work, compensation mechanisms that may reduce productivity loss, reduced productivity at work (efficiency losses) and productivity costs at the level of organizations. Using this questionnaire may facilitate the validity of estimates of productivity costs in economic evaluations of healthcare programs.