[Outcomes of hip replacement: a hospital-based longitudinal study in Lazio region (Italy)]

Hip replacement (HR) is a very effective procedure for chronic hip diseases especially in elderly. The aims of this study were: 1) to describe the typology of HRs; 2) to assess short and long term outcomes; 3) to evaluate the relationship between both individual and hospital characteristics with the outcomes. Regional hospital discharge data and mortality register were used. The study population included residents of the Lazio region, over 17 years of age, who underwent HR in any private or public hospital in Italy. We used logistic regression analysis to examine in-hospital mortality, 30-day mortality, 90-day mortality. Cox regression analysis was run to investigate revision and 3-5 year mortality. Out of 8159 HRs, 69.5% were total hip replacements (THR) conducted predominantly on females over 70 years of age. We observed 262 in-hospital deaths (7.4% endoprothesis, 1.4% THR). Thirty and 90-day mortality also showed a different pattern among the two procedures (endoprothesis 8.0% and 15.8%, THR 1.3% and 2.2%). At the end of the follow-up, 21% of patients had died and 204 revisions had been carried out (1.4% endoprothesis, 3.0% THR). Overall, 1898 patients (23.3%) had a revision or died. The main short and long term mortality risk factors were: age, male gender and comorbidities. Hospital volume was not associated with a significant mortality risk. For endoprothesis, waiting time before surgery longer than 7 days was associated with a 30-day mortality risk of 2.83. The present study prompted us to test methodologies to evaluate quality levels in orthopaedic surgery units throughout the region using information systems. Further studies are needed to better understand the variability in the characteristics of care that emerged in Lazio hospitals.