Abstract
Background The annual report of EndoCert publishes the results of the quality indicators (QI) and key figures of all certified centres for joint replacement (EndoProthetikZentren – EPZ). For some results it seems that centres with fewer revisions might have higher complication rates. However, to avoid misinterpretation the results have to be evaluated in more detail. The influence of the quantity of the revisions or the revision quotient on the quality of outcome was investigated.
Material and Methods This study included all certified EPZ and centres of excellence for joint replacement (EPXmax) (n = 492) and evaluated the data from 2016. Centres beyond the action limit were identified with the help of funnel plots and a confidence limit of 99.7% as action limit. Additionally data of the quality indicators were analysed with ANCOVA. The level of significance was p < 0.05.
Results The comparison by ANCOVA with number of revisions as co-variate showed no differences in the complication rates when related to the quantity of revisions. When considering a so called revision quotient (ratio of revision to all joint replacements) significant differences in the rate of fractures and fissures as well as in mortality for hip replacements and also in mortality for knee replacements were observed.
Conclusion EPZ with fewer revisions do not have higher complication rates than centers with high numbers of revisions. Thus, the quantity of revisions has no influence on the quality of the outcome, considering that on the basis of the data of the EndoCert system no risk adjustment of patient-specific data was performed. Therefore the revisioin quotient of an EPZ shows that quantity is not equal with quality.
Key words
EndoCert - quality indicators - quality of outcome - revision quotient - complication rate
