Prognostic factors associated with mortality in patients with septic arthritis: a descriptive cohort study

Objectives: To evaluate the 30-day mortality rate of septic arthritis (SA) in adults in Funen, central Denmark, and to explore whether, at the time of SA presentation, risk factors for the 30-day mortality rate could be revealed. Our secondary objective was to describe the microbiological aetiologies, systemic signs of inflammation, and co-morbidity.Method: A descriptive study identifying patients with SA from central Denmark, during the period 2006-2013, by the use of joint fluid culture data retrieved from the electronic database at the Department of Clinical Microbiology, Odense University Hospital. Patients with a positive joint fluid culture were considered eligible and their medical records were examined.Results: We identified 215 patients with SA, mean age 64.8years. At presentation, mean C-reactive protein (CRP) was 204mg/L, mean white blood cell count (WBC) 11.9 x 10(9)/L, and mean body temperature 37.6 degrees C. A total of 101 patients (47%) had a prosthetic joint, 46 (21%) had an inflammatory joint disease, and 24 (11%) had diabetes mellitus (DM). Staphylococcus aureus was the most common pathogen (104 patients, 48.4%). The 30-day mortality rate was 9.3% and the significant risk factor for death was liver disease at time of presentation [odds ratio (OR) 40.40, 95% confidence interval (CI) 5.38-303]. The other factors tested such as age > 65 years, elevated temperature, rheumatoid arthritis (RA), prostheses, and diabetes mellitus (DM) did not reach statistical significance.Conclusions: In our sample of patients with SA, we found a 30-day mortality rate in almost one in 10 adults. Among possible explanations, our study indicates that liver disease is a clinically relevant risk factor.