MICRO-COSTING CRITICAL APPRAISAL
Concerns about rising health care costs require rigorous economic study to inform clinical and policy decision-making. Advances in medical knowledge and technology results in rapid diffusion of new health interventions that cannot be precisely costed by existing estimates or prices. Micro-costing is particularly relevant for estimating costs of new interventions, but existing interventions, too, benefit from this methodology. By measuring detailed resource utilization and unit costs, micro-costing methodology generates precise cost estimates and has been considered the preferred method for estimating costs of health interventions. Micro-costing is a cost estimation methodology employing detailed resource utilization and unit cost data to generate precise estimates of economic costs.
In this paper, a critical appraisal of micro-costing studies in English was conducted. To inform future design and reporting of micro-costing studies, analysis was limited to studies that fully or predominantly used micro-costing in their cost estimation and studies that only partially or minimally involved micro-costing were excluded. To inform future research, the focus was on research studies with a defined patient sample and research question, studies with a primary goal to inform hospital financial management or estimate unit cost per medical service were excluded. As a result, 195 studies were critically appraised.
This critical appraisal of micro-costing studies in health and medicine suggests that use of micro-costing methods, while increasing, has largely varied in the quality of conducting and reporting of micro-costing analyses. Studies often did not adequately address key design issues and lacked sufficient detail or transparency in explaining study design. The few studies available that compared micro-costing with other costing methods suggest that micro-costing is the preferred method for generating accurate cost estimates, especially for studies that involve services that are labor intensive. These findings highlight the importance and need for rigorous guidelines to help standardize the conduct and reporting of micro-costing studies. Future efforts to develop a checklist specifically tailored to micro-costing studies will be instrumental.