These results suggest a direct relationship between explicit appropriateness criteria and better health-related quality-of-life outcomes after THR and TKR surgery. Our results support the use of these criteria for clinical guidelines or evaluation purposes.

The main predictor of outcome at 6 months post-operatively in all eleven domains was the pre-intervention score of each domain. Presence of social support, absence of low back pain and higher baseline SF-36 mental health score were related to the improvement in the health-related quality of life post-operatively.

The previous parameters tested showed acceptable results for an evaluation tool. These results support the use of this algorithm as an aid in formulating clinical practice guidelines and to promote the appropriateness of TKR.