Three-year revision rate of certified centres for joint replacement according to EndoCert Risk-adjusted analysis of outcome quality and comparison with other quality assurance systems

Background: The EndoCert initiative does not yet allow a long-term assessment of outcome quality. The assessment cannot be achieved without cooperation with the German arthroplasty registry (EPRD) and other quality assurance infrastructure, such as the quality assurance system of the nationwide healthcare insurance data for inpatient hospital treatment (QSR) by the German local healthcare fund (AOK). Therefore, the quality of care of all certified centres for joint replacement (EPZ) after primary hip and knee arthroplasty was to be examined for the first time. These data were subsequently compared to the data of the EPRD.Materials and methods: In EPZ that provided care to at least one AOK-insured patient in 2016, the risk-adjusted 3-year revision rate and the SMR-value (standardised mortality or morbidity ratio), which is the quotient of the observed and expected revision rate, were analysed as markers for the quality of care. Annual hospital volume, type of centre and audit results were examined as possible influencing factors.Results: In the group comparison, significant differences (p = 0.042) for the SMR value of the 3-year revision rate were demonstrated for hip arthroplasty with regard to the EPZ type. The annual number of primary hip arthroplasties, however, did not influence the 3-year revision rate. For knee arthroplasties, no effect of the defined categories on the 3-year revision rate and its SMR value was observed. The comparison of our 3-year revision rates with those of the EPRD showed similar results for the hip but indicated significant differences for the knee.Conclusion: We did not observe a correlation between quality of care and annual hospital volume in certified EPZ. However, different quality assurance procedures can lead to different results with respect to the outcome quality. Therefore, a considerably improved interaction of the German quality systems must be achieved. Participation in the EPRD is not sufficient for this. Rather, a complete report of all arthroplasties must be required, at least with the achievement of a minimum reporting rate per participating hospital. Uniform inclusion and exclusion criteria should be defined.