Improving prediction of surgical site infection risk with multilevel modeling.

BACKGROUND: Surgical site infection (SSI) surveillance is a key factor in the elaboration of strategies to reduce SSI occurrence and in providing surgeons with appropriate data feedback (risk indicators, clinical prediction rule). AIM: To improve the predictive performance of an individual-based SSI risk model by considering a multilevel hierarchical structure. PATIENTS AND METHODS: Data were collected anonymously by the French SSI active surveillance system in 2011. An SSI diagnosis was made by the surgical teams and infection control practitioners following standardized criteria. A random 20% sample comprising 151 hospitals, 502 wards and 62280 patients was used. Three-level (patient, ward, hospital) hierarchical logistic regression models were initially performed. Parameters were estimated using the simulation-based Markov Chain Monte Carlo procedure. RESULTS: A total of 623 SSI were diagnosed (1%). The hospital level was discarded from the analysis as it did not contribute to variability of SSI occurrence (p  = 0.32). Established individual risk factors (patient history, surgical procedure and hospitalization characteristics) were identified. A significant heterogeneity in SSI occurrence between wards was found (median odds ratio [MOR] 3.59, 95% credibility interval [CI] 3.03 to 4.33) after adjusting for patient-level variables. The effects of the follow-up duration varied between wards (p<10-9), with an increased heterogeneity when follow-up was <15 days (MOR 6.92, 95% CI 5.31 to 9.07]). The final two-level model significantly improved the discriminative accuracy compared to the single level reference model (p<10-9), with an area under the ROC curve of 0.84. CONCLUSION: This study sheds new light on the respective contribution of patient-, ward- and hospital-levels to SSI occurrence and demonstrates the significant impact of the ward level over and above risk factors present at patient level (i.e., independently from patient case-mix)

Antibiotic use in 530 French hospitals: results from a surveillance network at hospital and ward levels in 2007.

International audienceOBJECTIVES: Antibiotic use in French hospitals is among the highest in Europe. A study was carried out to describe antibiotic consumption for inpatients at hospital and at ward levels. METHODS: Data were voluntarily collected retrospectively by 530 hospitals accounting for approximately 40 million patient-days (PD) on the following: antibacterials for systemic use [J01 class of the WHO Anatomical Therapeutic Chemical (ATC) classification, defined daily doses (DDD) system, 2007], rifampicin and oral imidazole derivatives, expressed in number of DDD and number of PD in 2007. Consumption was expressed in DDD/1000 PD. RESULTS: Median antibiotic use ranged from 60 DDD/1000 PD in long-term care (LTC) and psychiatric hospitals to 633 DDD/1000 PD in teaching hospitals. Penicillins and beta-lactamase inhibitors combinations were the most frequently used antibiotics, accounting for 26% of total use in cancer hospitals to 40% in LTC/psychiatric hospitals. Glycopeptides and carbapenems were mostly used in cancer and teaching hospitals. Level of consumption and pattern of use differed according to clinical ward from 60 DDD/1000 PD in psychiatric wards up to 1466 DDD/1000 PD in intensive care units (ICUs). In medicine, surgery, ICU and rehabilitation wards, fluoroquinolones accounted for 13%-19% of the total use. CONCLUSIONS: This multicentre survey provided detailed information on antibiotic use in a large sample of hospitals and wards, allowing relevant comparisons and benchmarking. Analysis of consumption at the ward level should help hospitals to target practice audits to improve antibiotic use

Trends of Incidence and Risk Factors of Ventilator-Associated Pneumonia in Elderly Patients Admitted to French ICUs Between 2007 and 2014

International audienceOBJECTIVES: To assess trends and risk factors of ventilator-associated pneumonia according to age, particularly in the elderly admitted to French ICUs between 2007 and 2014. DESIGN: Multicenter, prospective French national Healthcare-Associated Infection surveillance network of ICUs ("Réseau REA-Raisin"). SETTINGS: Two-hundred fifty six ICUs in 246 settings in France. PATIENTS: Included were all adult patients hospitalized greater than or equal to 48 hours in ICUs participating in the network. INTERVENTIONS: Ventilator-associated pneumonia surveillance over time. MEASUREMENTS AND MAIN RESULTS: Overall and multidrug-resistant organism-related ventilator-associated pneumonia incidence rates were expressed per 1,000 intubation days at risk. Age was stratified into three groups: young (18-64 yr old), old (65-74 yr old), and very old (75+ yr old). Age-stratified multivariate mixed-effects Poisson regressions were undertaken to assess trends of ventilator-associated pneumonia incidence over time, with center as the random effect. Ventilator-associated pneumonia risk factors were also evaluated. Of 206,223 patients, 134,510 were intubated: 47.8% were young, 22.3% were old, and 29.9% were very old. Ventilator-associated pneumonia incidence was lower in the very old group compared with the young group (14.51; 95% CI, 16.95-17.70 vs 17.32; 95% CI, 16.95-17.70, respectively, p \textless 0.001). Methicillin-resistant Staphylococcus aureus and third-generation cephalosporin-resistant Enterobacteriaceae were identified more frequently in very old patients (p \textless 0.001 and 0.014, respectively). Age-stratified models disclosed that adjusted ventilator-associated pneumonia incidence decreased selectively in the young and old groups over time (adjusted incidence rate ratios, 0.88; 95% CI, 0.82-0.94; p \textless 0.001 and adjusted incidence rate ratios, 0.95; 95% CI, 0.86-1.04; p = 0.28, respectively). Male gender and trauma were independently associated with ventilator-associated pneumonia in the three age groups, whereas antibiotics at admission was a protective factor. Scheduled surgical ICU and immunodeficiency were risk factors of ventilator-associated pneumonia in the old group (p = 0.003). CONCLUSIONS: Ventilator-associated pneumonia incidence is lower but did not decrease over time in very old patients compared with young patients

Clinical, virological, and biological parameters associated with outcomes of Ebola virus infection in Macenta, Guinea

International audienceBACKGROUND. The pathogenesis of Ebola virus (EBOV) disease (EVD) is poorly characterized. The establishment of well-equipped diagnostic laboratories close to Ebola treatment centers (ETCs) has made it possible to obtain relevant virological and biological data during the course of EVD and to assess their association with the clinical course and different outcomes of the disease. METHODS. We were responsible for diagnosing EBOV infection in patients admitted to two ETCs in forested areas of Guinea. The pattern of clinical signs was recorded, and an etiological diagnosis was established by RT-PCR for EBOV infection or a rapid test for malaria and typhoid fever. Biochemical analyses were also performed. RESULTS. We handled samples from 168 patients between November 29, 2014, and January 31, 2015; 97 patients were found to be infected with EBOV, with Plasmodium falciparum coinfection in 18%. Overall mortality for EVD cases was 58%, rising to 86% if P. falciparum was also present. Viral load was higher in fatal cases of EVD than in survivors, and fatal cases were associated with higher aspartate aminotransferase (AST) and alanine aminotransferase (ALT), C-reactive protein (CRP), and IL-6 levels. Furthermore, regardless of outcome, EVD was characterized by higher creatine kinase (CPK), amylase, and creatinine levels than in febrile patients without EVD, with higher blood urea nitrogen (BUN) levels in fatal cases of EVD only. CONCLUSION. These findings suggest that a high viral load at admission is a marker of poor EVD prognosis. In addition, high AST, ALT, CRP, and IL-6 levels are associated with a fatal outcome of EVD. Damage to the liver and other tissues, with massive rhabdomyolysis and, probably, acute pancreatitis, is associated with EVD and correlated with disease severity. Finally, biochemical analyses provide substantial added value at ETCs, making it possible to improve supportive rehydration and symptomatic care for patients. FUNDING. The French Ministry of Foreign Affairs, the Agence Française de Développement, and Institut Pasteur