• Hip and knee surgery

BACKGROUND In Denmark, approximately 10,000 elective primary hip and knee arthroplasties were performed in 2004, and the hospital costs were close to US$ 100,000,000. Accelerated perioperative care and rehabilitation interventions are currently being implemented, although the evidence is weak. No evidence of efficiency in a societal perspective exists. Few studies have described the implementation process or how results obtained in effectiveness studies correspond to results obtained in efficacy studies. We therefore investigated the efficacy and efficiency of perioperative care and rehabilitation intervention compared to the current intervention after hip and knee arthroplasty. If efficacy and efficiency could be demonstrated, we then aimed to describe the implementation process and to investigate whether effectiveness could also be demonstrated. We finally wanted to investigate how results from efficacy and effectiveness studies corresponded. MATERIALS & METHODS Efficacy was investigated in a randomized clinical intervention trial, and efficiency in a piggy-back study to that study. We randomized 87 hip and knee patients to either a group receiving the current intervention or a group receiving the new accelerated perioperative care and rehabilitation intervention. In the efficacy study primary outcome was difference in length of stay at discharge between the two intervention groups. In the efficiency study primary outcome was incremental cost efficacy ratio between the two groups in a societal perspective during the first postoperative year. Effect was measured using quality-adjusted life-year (QALY). In the effectiveness study, we prospectively documented the implementation process of the accelerated perioperative care and rehabilitation intervention using the Breakthrough Series and active research. We evaluated effectiveness of the accelerated care and rehabilitation intervention in a before-after design that included 258 hip and knee patients. Primary outcome was difference in length of stay at discharge between the two groups. RESULTS In the efficacy study, mean length of stay was significantly reduced from 8 days in the group receiving the current intervention to 5 days in the group receiving the accelerated perioperative care and rehabilitation intervention. Efficiency was also demonstrated with the accelerated intervention being both less costly and more effective than the current intervention for the hip patients, and being less costly and with equal effect for the knee patients. We documented that the Breakthrough Series and active research functioned as implementation methods in orthopaedics. Length of stay was halved from one year to another after implementation of the accelerated perioperative care and rehabilitation intervention. Length of stay was significantly shorter in the effectiveness study compared to the efficacy study. CONCLUSIONS An accelerated perioperative care and rehabilitation intervention after hip and knee arthroplasty reach efficacy, effectiveness and efficiency compared to the current intervention. An accelerated intervention can successfully and effectively be implemented within a year. Results obtained in an effectiveness study with this intervention could actually match result obtained in an efficacy study in this population.