Clinical condition and comorbidity as determinants for blood culture positivity in patients with skin and soft-tissue infections.

The utility of performing blood cultures in patients with a suspected skin infection is debated. We investigated the association between blood culture positivity rates and patients' clinical condition, including acute disease severity and comorbidity. We performed a retrospective study, including patients with cellulitis and wound infection who had been enrolled in three Dutch multicenter studies between 2011 and 2015. Patients' acute clinical condition was assessed using the Modified Early Warning Score (MEWS; severe: MEWS ≥2) and comorbidity with the Charlson Comorbidity Index (CCI; severe: CCI ≥2). A total of 334 patients with a suspected skin infection were included. Blood cultures were performed in 175 patients (52%), 28 of whom (16%) had a positive blood culture. Data on the clinical condition were collected in 275 patients. Blood cultures were performed in 76% of the patients with a severe acute condition, compared with 48% with a non-severe acute condition (OR 3.5; 95% confidence interval: 2.0-6.2; p < 0.001). Blood cultures were positive in 18% and 12% respectively (OR 1.7 (0.7-4.1); p = 0.3). Blood cultures were performed in 53% of patients with severe comorbidity, compared with 61% without severe comorbidity (OR 0.7; 0.4-1.2; p = 0.2). Blood cultures were positive in 25% and 10% respectively (OR = 3.1; 1.2-7.5; p = 0.02). The blood culture positivity rate among hospitalized patients diagnosed with skin infections was higher than the rates reported by the Infectious Diseases Society of America guidelines, particularly in patients with severe comorbidity. Therefore, the recommendations concerning blood culture performance in patients with a skin infection should be reconsidered.

Applicability of generic quality indicators for appropriate antibiotic use in daily hospital practice: a cross-sectional point-prevalence multicenter study.

The ability to monitor the appropriateness of hospital antibiotic use is a key element of an effective antibiotic stewardship program. A set of 11 generic quality indicators (QIs) was previously developed to assess the quality of antibiotic use in hospitalized adults treated for a bacterial infection. The primary aim of the current study was to assess the clinimetric properties of these QIs (nine process and two structure indicators) in daily clinical practice. In a cross-sectional point-prevalence survey, performed in 2011 and 2012, 1890 inpatients from 22 hospitals in the Netherlands treated with antibiotics for a suspected bacterial infection were included, and data were extracted from medical records. In this cohort we tested the measurability, applicability, reliability, room for improvement and case mix stability of the previously developed QIs. Low applicability (≤10% of reviewed patients) was found for the QIs 'therapeutic drug monitoring', 'adapting antibiotics to renal function' and 'discontinue empirical therapy in case of lack of clinical and/or microbiological evidence of infection'. For the latter, we also found a low inter-observer agreement (kappa <0.4). One QI showed low improvement potential. The remaining seven QIs had sound clinimetric properties. Case-mix correction was necessary for most process QIs. For all QIs, we found ample room for improvement and large variation between hospitals. Establishing the clinimetric properties was essential, as four of the 11 previously selected QIs showed unsatisfactory properties in this practice test. Since the quality of antibiotic use and the process of documenting data is changing over time and may vary per country, QIs should always be tested in practice first.