At what time is a reduction of medical under- or overtreatment sensible? Treatment of acute depression as an example

Objective: 1) To portray the mathematical relationship between the size of an underuse or overuse problem caused by non-compliance of health professionals and the cost-effectiveness of a quality improvement program; 2) to demonstrate the applicability of the models to a real-world problem (underuse and overuse in the treatment of major depression) and to stress the importance of the costs of a quality improvement program using this example. Methods: Mathematical formulation of the relationship between the costs of a quality improvement program and the degree of underuse and overuse. Results: The example of reducing underuse in the treatment of major depression shows that an intervention with a favorable cost-effectiveness ratio may be economically unattractive if a quality improvement program incurs high costs secondary to a small quality deficit. The application example also shows that reducing treatment overuse is inefficient if overuse is small and hence the costs of a quality improvement program are higher than the costs of overuse. Conclusions: The explicit consideration of the size of an underuse or overuse problem in the cost-effectiveness ratio of a quality improvement program may contribute to a more efficient use of health care resources.