Differences in production between medical specialists: An inventory based on claims data to identify potential areas for quality-improvement activities

Claims data from sickness funds were used to describe practice patterns of all physician partnerships of six medical specialties in a region of The Netherlands. The numbers of admissions to hospital, patient days, in-patient and out-patient procedures were compared per 1,000 insured persons. There were large differences among physicians within the same specialties. The non-surgical specialties had more variable practice patterns. Variation in use of specific procedures with a supposedly clear indication versus a less-defined indication was the same. We could not identify special areas with greater differences that should have a priority for quality-improvement activities. The use of sickness fund data in monitoring and decreasing variations in medical practice is discussed.