OBJECTIVES: Productivity is utilised inconsistently in value assessment and pose methodological and conceptual barriers for estimation. This review aimed to examine the utilization of productivity gain/loss assessments in patients and caregivers in health economic evaluations.

METHODS: Systematic literature review was conducted using PubMed, Ovid MEDLINE, Embase, Japanese databases (J-STAGE and Ichushi Web), and economic literature databases. Studies published between January 2021 and December 2023 which presented economic evaluations were included.

RESULTS: Out of 1431 identified studies, 152 were included. These studies were uniformly distributed, with a slightly increase in 2023 versus 2021, accounting for 54 (35.5%) and 48 (31.6%) studies, respectively. The geographical distribution of these studies was: Europe=73, Asia=40, North America=22, Latin America=2. Productivity measures were assessed mostly in patients with mental, behavioural, or neurodevelopmental disorders (16.4%) followed by cancer (11.2%). Most of the studies assessed adult patients from both genders. 138 studies reported patient measures, while 34 reported caregiver measures.

This review further explored 20 out of the 88 identified instruments. Work Productivity and Activity Impairment Questionnaire (WPAI) (23/152), iMTA Productivity Cost Questionnaire (iPCQ) (23/152) and Trimbos/iMTA Questionnaire for Costs associated with Psychiatric Illness (TIC-P) (8/152) were most commonly used productivity instruments. All these instruments are well-validated and proven to be reliable. Human capital approach (18) and friction cost approach (17) were utilized to assign monetary value to the lost productivity. All three instruments reported absenteeism, presenteeism, and overall work impairment. WPAI additionally included information on daily activity impairment.

CONCLUSIONS: This review identified a significant quantity of health economic evaluations employing productivity measures between 2021 and 2023. Various instruments were used to measure productivity loss in these studies, with a few being commonly utilized across studies. A standard approach should be established to make sure that productivity gain/loss is captured consistently in value assessment for innovative therapies.