Clinical and economic outcomes of infective endocarditis.

BACKGROUND: In France, the estimated annual incidence of infective endocarditis (IE) is 33.8 cases per million residents. Valvular surgery is frequently undergone. We report an epidemiological and economic study of IE for 2007-2009 in a French region, using the hospital discharge database (HDD). METHODS: The population studied concerned all the patients living in Centre region, France, hospitalized for IE. We extracted hospital stay data for IE from the regional HDD, with a definition based on IE-related diagnosis codes. The predictive positive value (PPV) and sensitivity (Se) of the definition were 87.4% and 90%, respectively, according to the Duke criteria (definite IE frequency 74.4%). Hospitalization costs were estimated, taking into account the fixed hospital charges of the diagnosis-related group (DRG) and supplementary charges due to intensive care unit (ICU) stay. RESULTS: The analysis included 578 patients. The annual average incidence was 45.4 cases per million residents. Valvular surgery was performed in 19.4% of cases. The hospital mortality was 17.6%. Multivariate analysis identified as risk factors for mortality an age ≥ 70 years (odds ratio (OR) = 3.03, 95% confidence interval (CI) = 1.78-5.18), staphylococcal IE (OR = 3.3, 95% CI = 1.9-5.7), chronic renal insufficiency (OR = 2.04, 95% CI = 1.00-4.15), ischemic stroke (OR = 2.55, 95% CI = 1.19-5.47), and hemorrhagic stroke (OR = 5.7, 95% CI = 1.9-17.3). The average cost per episode was $20 103 (€15 281). CONCLUSIONS: We report a higher incidence of IE than described by the French national study of 2008. Valvular surgery was considerably less frequent than in the published data, whereas mortality was similar. IE generates substantial costs.

Quality assessment of hospital discharge database for routine surveillance of hip and knee arthroplasty-related infections.

OBJECTIVE: Surgical site infection (SSI) surveillance represents a key method of nosocomial infection control programs worldwide. However, most SSI surveillance systems are considered to be poorly cost effective regarding human and economic resources required for data collection and patient follow up. This study aims to assess the efficacy of using hospital discharge databases (HDDs) as a routine surveillance system for detecting hip or knee arthroplasty-related infections (HKAIs). METHODS: A case-control study was conducted among patients hospitalized in the Centre region of France between 2008 and 2010. HKAI cases were extracted from the HDD with various algorithms based on the International Classification of Diseases, Tenth Revision, and procedure codes. The control subjects were patients with hip or knee arthroplasty (HKA) without infection selected at random from the HDD during the study period. The gold standard was medical chart review. Sensitivity (Se), specificity (Spe), positive predictive value (PPV), and negative predictive value (NPV) were calculated to evaluate the efficacy of the surveillance system. RESULTS: Among 18,265 hospital stays for HKA, corresponding to 17,388 patients, medical reports were checked for 1,010 hospital stays (989 patients). We identified 530 cases in total (incidence rate, 1% [95% confidence interval (CI), 0.4%-1.6%), and 333 cases were detected by routine surveillance. As compared with 480 controls, Se was 98%, Spe was 71%, PPV was 63%, and NPV was 99%. Using a more specific case definition, based on a sample of 681 hospital stays, Se was 97%, Spe was 95%, PPV was 87%, and NPV was 98%. CONCLUSIONS: This study demonstrates the potential of HDD as a tool for routine SSI surveillance after low-risk surgery, under conditions of having an appropriate algorithm for selecting infections.