When is it worth introducing a quality improvement program? A mathematical model.

Quality improvement programs must compete with other health care interventions for limited health care resources. The goal of the research presented here was to develop a model that portrays the mathematical relationship between the size of a quality deficit caused by the noncompliance of health professionals and the cost-effectiveness of a quality improvement program. The model allows the determination of the minimum size of a quality deficit for which it is worth introducing a quality improvement program. If a quality improvement program has already been implemented, the model can be used to define the quality threshold beyond which a reduction in quality becomes economically unattractive. An example considering the reduction of underuse in depression treatment demonstrates that an intervention with a favorable cost-effectiveness ratio may become economically unattractive once the costs for the implementation effort are considered.