Economic evaluations of occupational health interventions from a company's perspective: a systematic review of methods to estimate the cost of health-related productivity loss

Objectives: To investigate the methods used to estimate the indirect costs of health-related productivity in economic evaluations from a company's perspective. Methods: The primary literature search was conducted in Medline and Embase. Supplemental searches were conducted in the Cochrane NHS Economic Evaluation Database, the National Institute for Occupational Safety and Health database, the Ryerson International Labour, Occupational Safety and Health Index database, scans of reference lists and researcher's own literature database. Article selection was conducted independently by two researchers based on title, keywords, and abstract, and if needed, full text. Differences were resolved by a consensus procedure. Articles were selected based on seven criteria addressing study population, type of intervention, comparative intervention, outcome, costs, language and perspective, respectively. Characteristics of the measurement and valuation of health-related productivity were extracted and analyzed descriptively. Results: A total of 34 studies were included. Costs of health-related productivity were estimated using (a combination of) data related to sick leave, compensated sick leave, light or modified duty or work presenteeism. Data were collected from different sources (e.g. administrative databases, worker self-report, supervisors) and by different methods (e.g. questionnaires, interviews). Valuation varied in terms of reported time units, composition and source of the corresponding price weights, and whether additional elements, such as replacement costs, were included. Conclusions: Methods for measuring and valuing health-related productivity vary widely, hindering comparability of results and decision-making. We provide suggestions for improvement. © 2010 The Author(s).