OBJECTIVES : Different valuation methods are used for monetary valuation of productivity loss. This could lead to different study outcomes and limit comparability. Insight into the applied methods can contribute to the awareness of the different methods used, add to the discussion of implications for differences in outcomes, and promote the search for best practice and harmonization of methods. This study aimed to perform a systematic literature review of valuation methods of productivity loss of paid and unpaid work in health economic evaluations.

METHODS : PubMed/Medline, PsycInfo, Embase, and Econlit were searched for economic evaluations in which productivity loss was valued in monetary terms. Valuation approaches, types of unit costs (e.g. average wage) and units of measurement (e.g. hours, days) were extracted from the eligible papers.

RESULTS : In total, 377 studies were included. Paid productivity loss was valued using the human capital method (HCM) and/or friction cost method (FCM), 135 unit costs, and in time (e.g. hours) or percentages. The HCM and mean wage were applied most frequently for paid work. Unpaid productivity loss was valued using the proxy good method, opportunity costs method, or in rare cases the HCM or modified FCM, 24 unit costs, and in hours or days.

CONCLUSIONS : This study confirms the findings of previous research that most health economic evaluations applied the HCM and to less extend the FCM for the valuation of productivity loss of absence of paid work. Existing literature is ambiguous about the methodology applied to estimate reduced productivity while at work and unpaid production loss. Moreover, types of unit costs used for the valuation of paid and unpaid productivity loss show a lack of clarity and homogeneity. Future research should focus on the methodological rationale of particular unit costs for the valuation of production loss of paid and unpaid work.