[Convergence tendencies in inpatient oncological care after implementation of diagnosis-related groups in Germany]

An increase of the convergence of medical services towards specialised hospitals with high case numbers is often assumed as a result of the implementation of diagnosis-related groups (DRG; case-based lump sum reimbursement). So far, estimates of the extent to which this effect occurs after the recent implementation of DRGs are not available in Germany.

Claims data of about 23,600,000 insured within the inclusive period 2004-2007 were analysed. All cases with the main diagnosis of lung cancer, prostate cancer, and colorectal cancer were included in the study. Broken down by entities and years, graphical and statistical concentration measures as well as the percentages of different hospital size classes were calculated.

Increasing case numbers could be observed for all entities within the period (lung cancer:+25.7%; prostate cancer:+12.5%; colorectal cancer:+8.1%). The concentration measures showed hardly any changes in the course of time. The absolute increase of case numbers seems to affect those hospitals with case numbers higher than 50 per year above average [lung cancer cases in a hospital group including hospitals with more than 50 cases 2004 (percentage): 78.1% and 2007: 81.6%; prostate cancer: 67.4% and 71.7%; colorectal: 72.5% and 75.9%], whereas case numbers of hospital groups including hospitals with case numbers less than 50 per year remain unchanged or grow more slowly.

The convergence of oncological services towards a few specialised centres has not yet been accelerated by the implementation of DRG's. Fundamentally, relative changes can be noticed due to case number increases in large centres, not because of service cutbacks and shifts from smaller hospitals. Reasons for this could either be the inflexibility of capacity planning or control options of the statutory health insurance.

Further research of convergence tendencies and its drivers is required to be able to draw any benefit from efficiency and quality potentials.