Use of Productivity Loss/Gain in Cost-Effectiveness Analyses for Drugs: A Systematic Review

BACKGROUND: Inclusion of productivity losses and gains in cost-effectiveness analyses for drugs is recommended by pharmacoeconomic guidelines in some countries and is considered optional in others. Often guidelines recommend analysis based on the payer perspective, but suggest that a supplemental analysis based on the societal perspective may be submitted that includes productivity losses/gains. However, there is no universally recognized framework for the approach to including productivity losses and gains in pharmacoeconomic analyses. OBJECTIVES: This study aimed to systematically review literature on cost-effectiveness analyses of drug interventions that included costs associated with productivity losses/gains and to summarize the types cost elements included and cost calculation methods employed. Moreover, this study examines variations in the calculation of productivity losses/gains by target disease type, geographic region, income group, period of analysis, and analysis time horizon-as well as the impact of their inclusion on the study outcomes. METHODS: A search of three databases was performed, including MEDLINE, Embase, and the Cochrane Library, to identify cost-effectiveness and cost-utility analyses that included indirect costs such as productivity losses/gains. Publications from January 2010 to October 2019 were examined and selected for inclusion by two independent reviewers. In addition to the citation details, data on the country of analysis, country income group, target disease area, study sponsorship, type of analysis, study design, time horizon, analysis perspective, productivity loss/gain elements included, the approach used to estimate productivity losses/gains, and the impact of their inclusion on the study outcome-namely the incremental cost effectiveness ratio-were extracted and summarized. RESULTS: The search strategy identified 5038 unique studies, and 208 were included in the final analysis. Among the studies reviewed, 165 (79%) were conducted in high-income countries and 160 (77%) were conducted for North American and European/Central Asian countries. The productivity loss/gain elements included in the analysis were reported for 169 studies (81%). Absenteeism only was included for 98 studies (47%), and absenteeism plus presenteeism was included for 29 studies (14%). Absenteeism plus some other element such as costs associated with unemployment and/or early retirement was included for 32 studies (15%) examined. Only one out of four of the studies reviewed included information on the approach used to estimate productivity losses/gains, which was predominantly the human capital approach. One-hundred forty-four studies (69%) reported the impact of including productivity losses/gains on the ICER, with 110 studies (53%) reporting that their inclusion contributed to more favorable cost-effectiveness. CONCLUSIONS: Although inclusion of productivity losses/gains was shown to have a favorable impact on evaluations for many studies, their impact and method of calculation was often not reported or was unclear. Further examination and discussion is needed to consider the optimal framework for considering productivity losses/gains in cost-effectiveness analyses, including the appropriate cost elements to include (e.g., patient absenteeism, caregiver absenteeism, presenteeism, unemployment, etc.) and how those costs should be estimated.