Aim: To assess the volume-outcome relationship of total hip replacement means of a Health Technology Assessment and to assess the effects of a minimum provider volume regulation on medical care in Germany
Methods: Electronic bibliographic databases, the reference lists of relevant articles and various health services research-related resources were searched and selected studies were assessed using defined quality criteria. Additionally, the implementation of these results and its consequences – excluding hospitals and/or surgeons that do not perform a defined number of operations a year from medical care – for the German Health System were calculated on routine data basis of the German Health insurance. Several different cut-off points (20 operations per year/50 operations per year) and the respective consequences on medical care were calculated.
Results: 26 publications, that comprise in a narrower sense with the volume-outcome-relationship of total hip replacement, were assessed. The results in literature concerning defined outcome parameters are inconsistent, but a general correlation between high volume and low complication rate could be identified. In contrast a cut-off point, that is able to discriminate “good” from “bad” health care could not be deduced from the results in the literature. Methodological aspects of the performed studies concerning volume-outcome relationship are to be considered, too, i.e. study design, statistics, endpoint definition. In Germany 1264 hospitals performed 150.000 total hip replacements in 2005. Implementing a regulation based on minimum provider volumes of 20/50 total hip replacements/year would lead to an exclusion of 216 (17%)/483 (38%)hospitals respectively from medical care. This would result in a reallocation of 2214 (1.4%)/11.478 (7,4%) patients/ year respectively.
Conclusion: Importance of HTA reports and expected consequences on health care will even increase in Germany especially regarding recent legal context. A correlation between high volume and low complication rate in total hip replacement could be identified by means of HTA. Keeping these results in mind and knowing that in consequence hospitals/surgeons that do not perform a defined number of operations a year will be excluded from medical care, the application of a minimum provider volume regulation in the German health care system must be performed very sensitve, because significant effects are to be expected.