Improving prediction of surgical site infection risk with multilevel modeling

• Published in: PloS one 2014-05, Vol.9 (5), p.e95295-e95295
• Main Authors: Saunders, Lauren, Perennec-Olivier, Marion, Jarno, Pascal, L'Hériteau, François, Venier, Anne-Gaëlle, Simon, Loïc, Giard, Marine, Thiolet, Jean-Michel, Viel, Jean-François
• Format: Article
• Language: English
• Subjects: Aged; Antibiotics; Computer simulation; Disease control; Epidemiological Monitoring; Female; Health aspects; Health risks; Health surveillance; Heterogeneity; Hospitals; Humans; Infection; Infection control; Infections; Infectious diseases; Intensive care; Logistic Models; Male; Markov Chains; Markov processes; Medical personnel; Medicine and Health Sciences; Middle Aged; Model accuracy; Models, Biological; Monte Carlo Method; Monte Carlo methods; Multilevel Analysis; Nosocomial infections; Parameter estimation; Patients; Performance prediction; Physical Sciences; Pseudomonas aeruginosa; Public health; Regression analysis; Regression models; Research and Analysis Methods; Risk analysis; Risk assessment; Risk Assessment - methods; Risk Factors; Statistical analysis; Structural hierarchy; Studies; Surgeons; Surgery; Surgical site infections; Surgical Wound Infection - epidemiology; Surveillance
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0095295

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). To improve the predictive performance of an individual-based SSI risk model by considering a multilevel hierarchical structure. 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. 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