Major article
Diabetes mellitus is associated with increased risk of surgical site infections: A meta-analysis of prospective cohort studies

https://doi.org/10.1016/j.ajic.2015.04.003Get rights and content

Highlights

  • Meta-analysis of 14 prospective cohort studies.

  • Patients with diabetes mellitus are almost twice as likely to develop surgical site infections when compared with patients without diabetes mellitus.

Background and Objective

Observational studies have suggested an association between diabetes mellitus and the risk of surgical site infections (SSIs), but the results remain inconclusive. We conducted a meta-analysis of prospective cohort studies to elucidate the relationship between diabetes mellitus and SSIs.

Methods

We searched PubMed, Embase, and Web of Science databases and reviewed the reference lists of the retrieved articles to identify relevant studies. Associations were tested in subgroups representing different patient characteristics and study quality criteria. The random-effect model was used to calculate the overall relative risk (RR).

Results

Fourteen prospective cohort studies (N = 91,094 participants) were included in this meta-analysis, and the pooled crude RR was 2.02 (95% confidence interval, 1.68-2.43) with significant between-study heterogeneity observed (I2 = 56.50%). Significant association was also detected after we derived adjusted RRs for studies not reporting the adjusted RRs and calculated the combined adjusted RR of the 14 studies (RR, 1.69; 95% confidence interval, 1.33-2.13). Results were consistent and statistically significant in all subgroups. Stratified analyses found the number of confounders adjusted for, sample size, and method of diabetes case ascertainment might be the potential sources of heterogeneity. Sensitivity analysis further demonstrated the robustness of the result.

Conclusions

This meta-analysis suggests diabetes mellitus is significantly associated with increased risk of SSIs. Future studies are encouraged to reveal the mechanisms underlying this association.

Section snippets

Literature search

We conducted this meta-analysis in accordance with the Meta-Analysis of Observational Studies in Epidemiology guidelines.8 We searched PubMed, Embase, and Web of Science databases up to December 23, 2014, by using the following search terms: diabetes mellitus, impaired glucose tolerance, impaired fasting glucose, glucose metabolism disorders, or insulin resistance in combination with surgical site infections. Reference lists of the retrieved articles were also reviewed. We did not contact

Literature search

The search strategy retrieved 1,266 unique studies. Of these, 1,185 studies were excluded after the first screening based on abstracts or titles, leaving 81 articles for full-text review. After assessing the full-text of the 81 potentially relevant articles, 67 articles were excluded for the reasons listed in Figure 1, leaving 14 studies22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 included for the final analyses.

Study characteristics

Characteristics of the 14 included studies are shown in Table 1. All were

Discussion

From the overall meta-analysis, patients with diabetes are almost twice as likely to develop SSIs when compared with patients without diabetes. The significantly increased risk of SSIs is also detected in the analysis that combines RRa of SSIs for patients with diabetes compared with those without diabetes, although the association becomes slightly weaker. In addition, the association persists and remains statistically significant across a number of stratified analyses exploring clinical and

Conclusions

Our analyses indicate that presence of diabetes is significantly associated with an increased SSI risk. Considering the consistent findings of increased SSI risk associated with diabetes across a number of prospective cohort studies and the reliability and robustness of our meta-analysis, we strongly recommend that future studies focus on the plausible causal mechanisms. Intervention studies concerning perioperative blood glucose control are also warranted to confirm this observed association

References (40)

  • W.J. Martone et al.

    Recognition, prevention, surveillance, and management of surgical site infections: Introduction to the problem and symposium overview

    Clin Infect Dis

    (2001)
  • K.B. Kirkland et al.

    The impact of surgical-site infections in the 1990s: Attributable mortality, excess length of hospitalization, and extra costs

    Infect Control Hosp Epidemiol

    (1999)
  • J. Alonso-Echanove et al.

    Effect of nurse staffing and antimicrobial-impregnated central venous catheters on the risk for bloodstream infections in intensive care units

    Infect Control Hosp Epidemiol

    (2003)
  • S.J. Finney et al.

    Glucose control and mortality in critically ill patients

    JAMA

    (2003)
  • D.F. Stroup et al.

    Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis of observational studies in epidemiology (moose) group

    JAMA

    (2000)
  • A. Stang

    Critical evaluation of the newcastle-ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses

    Eur J Epidemiol

    (2010)
  • S.L. Spruance et al.

    Hazard ratio in clinical trials

    Antimicrobial Agents Chemother

    (2004)
  • J. Zhang et al.

    What's the relative risk? A method of correcting the odds ratio in cohort studies of common outcomes

    JAMA

    (1998)
  • O. Miettinen

    Estimability and estimation in case-referent studies

    Am J Epidemiol

    (1976)
  • L.A. McNutt et al.

    Estimating the relative risk in cohort studies and clinical trials of common outcomes

    Am J Epidemiol

    (2003)
  • Cited by (0)

    Conflicts of interest: None to report.

    View full text