Septic arthritis significantly increased the long-term mortality in geriatric patients

Abstract Background The elderly are predisposed to septic arthritis (SA) because of the aging nature and increasing comorbidities. SA may in turn increase the long-term mortality in the geriatric patients; however, it remains unclear. We conducted this prospective nationwide population-based cohort study to clarify this issue. Methods Using Taiwan National Health Insurance Research Database (NHIRD), we identified 1667 geriatric participants (≥ 65 years) with SA and 16,670 geriatric participants without SA matched at a ratio of 1:10 by age, sex, and index date between 1999 and 2010. A comparison of the long-term mortality between the two cohorts through follow-up until 2011 was performed. Results Geriatric participants with SA had a significantly increased mortality than those without SA [Adjusted hazard ratio (AHR): 1.49, 95% confidence interval (CI): 1.34–1.66], particularly the old elderly (≥ 85 years, AHR: 2.12, 95% CI: 1.58–2.84) and males (AHR: 1.54, 95% CI: 1.33–1.79). These results were stated after adjustment for osteoarthritis, diabetes, gout, renal disease, liver disease, cancer, rheumatoid arthritis, systemic lupus erythematosus, alcoholism, and human immunodeficiency virus infection. The increased mortality risk was highest in the first month (AHR: 3.93, 95% CI: 2.94–5.25) and remained increased even after following up for 2–4 years (AHR: 1.30, 95% CI: 1.03–1.65). After Cox proportional hazard regression analysis, SA (AHR: 1.37, 95% CI: 1.20–1.56), older age (≥ 85 years, AHR: 1.79, 95% CI: 1.59–2.02, 75–84 years, AHR: 1.65, 95% CI: 1.53–1.78), male sex, diabetes, renal disease, liver disease, cancer, and gout were independent mortality predictors. There was no significant difference in the mortality for SA between upper limb affected and lower limb affected. Conclusions This study delineated that SA significantly increased the long-term mortality in geriatric participants. For the increasing aging population worldwide, strategies for the prevention and treatment of SA and concomitant control of comorbidities are very important.