Effect of the number of door openings in the operating room on surgical site infections: individual-patient data meta-analysis

Abstract

Background: The effect of door openings in the operating room on surgical site infections remains a controversial topic and has led to strict door-opening policies. The aim of this individual-patient data meta-analysis was to evaluate the effect of the number of door openings in the operating room on surgical site infection.

Methods: MEDLINE (PubMed) and Embase (Ovid) were searched up to 2 December 2024. Authors with individual-patient data on surgical site infections and door openings were invited to collaborate. A one-stage individual-patient data meta-analysis accounting for heterogeneity was performed to examine effects overall and in subgroup analyses (wound class, implant surgery, and income level). The primary outcome was surgical site infection. The risk of bias and Grading of Recommendations, Assessment, Development, and Evaluation framework were used to determine the certainty of evidence.

Results: Individual-patient data from 8 observational studies, encompassing 4412 patients, revealed a 6.0% incidence of surgical site infection. Each extra door opening per hour was associated with increased risk of surgical site infection (odds ratio 1.012, 95% c.i. 1.005 to 1.019; τ2 = 0.095; very low certainty of evidence). This means that, for example, at a baseline infection risk of 2%, approximately 35 additional door openings per hour per surgery would be needed to cause one additional surgical site infection per 100 patients. In subgroup analyses, no differences in effect were found. The cumulative effect was more pronounced in patients with a high baseline risk of surgical site infection.

Conclusion: Very low certainty of evidence suggests a marginal increase in the risk of surgical site infection for each additional door opening per hour. Although the relative effect is minimal, the cumulative effect has an impact on patients with a higher baseline surgical site infection risk more than others. However, the certainty of the available evidence is too low and the relative effect on clinical outcomes too small to support a rigorous zero door-openings policy to reduce rates of surgical site infections.

Fig. 1

PRISMA-IPD flow diagram PRISMA-IPD, Preferred Reporting Items for Systematic Reviews and Meta-Analysis of Individual Patient Data; IPD, individual-patient data; SSI, surgical site infection. ©Reproduced with permission of the PRISMA IPD Group, which encourages sharing and reuse for non-commercial purposes.

Fig. 2

Effect of door openings on the rate of surgical site infections The plot shows the effect of the number of door openings per hour on the rate of surgical site infections (SSIs) from a one-step meta-analysis of individual-patient data using a random-effects framework, and corrected for confounders. The pink lines show the absolute increase in SSI risk for every extra door opening per hour (odds ratio 1.012, 95% c.i. 1.005 to 1.019) for every possible scenario in the model. The absolute increase in SSI risk is shown for three baseline SSI risks: 1, 10, and 30%. Variables included in the model were: age, sex, body mass index, smoking, diabetes, the use of appropriate systemic antibiotic prophylaxis, American Association of Anesthesiologists grade, level of wound contamination according to the Centers for Disease Control and Prevention criteria, emergency surgery, procedure duration, income level of the country where the study was conducted, implantation of a foreign body, and study as a random effect. The vertical dotted line represents the commonly recommended threshold of 10 door openings per hour, as often suggested in guidelines.