A Systematic Review of Risk Factors Associated with Surgical Site Infections among Surgical Patients

Abstract

ImportanceSurgical site infection (SSI) complicates 2-5% of surgeries in the United States. Severity of SSI ranges from superficial skin infection to life-threatening conditions such as severe sepsis, and SSIs are responsible for increased morbidity, mortality, and economic burden associated with surgery. Staphylococcus aureus (S. aureus) is a commonly-isolated organism for SSI, and methicillin-resistant S. aureus SSI incidence is increasing globally.ObjectiveThe objective of this systematic review was to characterize risk factors for SSI within observational studies describing incidence of SSI in a real-world setting.Evidence ReviewAn initial search identified 328 titles published in 2002-2012; 57 were identified as relevant for data extraction. Extracted information included study design and methodology, reported cumulative incidence and post-surgical time until onset of SSI, and odds ratios and associated variability for all factors considered in univariate and/or multivariable analyses. FindingsMedian SSI incidence was 3.7%, ranging from 0.1% to 50.4%. Incidence of overall SSI and S. aureus SSI were both highest in tumor-related and transplant surgeries. Median time until SSI onset was 17.0 days, with longer time-to-onset for orthopedic and transplant surgeries. Risk factors consistently identified as associated with SSI included co-morbidities, advanced age, risk indices, patient frailty, and surgery complexity. Thirteen studies considered diabetes as a risk factor in multivariable analysis; 85% found a significant association with SSI, with odds ratios ranging from 1.5-24.3. Longer surgeries were associated with increased SSI risk, with a median odds ratio of 2.3 across 11 studies reporting significant results.Conclusions and RelevanceIn a broad review of published literature, risk factors for SSI were characterized as describing reduced fitness, patient frailty, surgery duration, and complexity. Recognition of risk factors frequently associated with SSI allows for identification of such patients with the greatest need for optimal preventive measures to be identified and pre-treatment prior to surgery.

Temporal trends and epidemiology of Staphylococcus aureus surgical site infection in the Swiss surveillance network: a cohort study

“…increases in wound contamination class) were associated with decreased risk of S. aureus SSI. One the one hand, this is contrary to some evidence; 12,28 on the other hand, contaminated surgical procedures concern mostly abdominal surgery with enteric bacteria as most frequent causes of SSI. Moreover, we excluded polymicrobial SSI containing S.…”

Development of Risk Scoring Tool to Predict Surgical Site Infections

“…Moreover, certain SSI predictors reported in the literature, such as age, S. aureus colonization, use of medical device, length of preoperative stay and surgery duration [35], were not captured in the NSQIP database and therefore, were not assessed in this analysis. Albeit, the study aim to create a user-friendly risk scoring tool may have been hindered by the inclusion of many variables.…”

“…The risk factors with continuous scales were dichotomized for statistical purposes. The BMI abnormality original classification included underweight (< 18.5), overweight (25)(26)(27)(28)(29)(30), class I obese (30)(31)(32)(33)(34)(35), class II obese (35)(36)(37)(38)(39)(40) and class III obese (> 40) groups as per pre-defined NSQIP BMI ranges. The altered classification classified BMI levels below 18.5 and above 25 as abnormal (under/overweight) and those between 18.5 and 25 as normal [27].…”

Multifocal Synchronous Chromophobe, Papillary, and Clear Cell Renal Cell Carcinoma in a Single Kidney

“…Some factors, such as patient age and gender are fixed but other potential variables, e.g., nutritional status, smoking, rational antibiotic use, compliance with asepsis-antisepsis techniques, technical conditions of the operating room, and intraoperative techniques, can be improved to provide positive surgical outcomes (1,16). A systematic review of 57 studies conducted in various countries showed that a high body mass index, severe wound class, diabetes, and a high NNIS risk index were associated with increased SSIs (17). The NNIS index is a classification developed by the CDC to identify risk of SSIs after surgery and compare the infection rates between surgical patients (18).…”