28 The effect of the number of operating room door openings on surgical site infection risk: an individual patient data meta-analysis

Abstract Background The effect of the number of door openings in the operating room (OR) on surgical site infections (SSI) risk remains a controversial topic. Many SSI prevention bundles include a restriction on the maximum number of door openings as intervention, often to ten per hour. However, existing evidence is limited and heterogeneous. This individual participant data (IPD) meta-analysis aims to evaluate the effect of the number of door openings in the OR on SSI occurrence. Methods We searched MEDLINE (Pubmed) and Embase (Ovid) up to 15 January 2024, for studies investigating the effect of the number of door openings on SSI incidence. Authors of eligible studies were invited to collaborate. IPD were merged and analysed with a logistic regression model with mixed-effects. This study is registered with PROSPERO, CRD42022309958. Findings IPD from eight observational studies, encompassing 4412 patients, revealed a 6.0% overall SSI incidence. The logistic regression model with mixed-effects indicated a difference in SSI risk for each extra door opening per hour (OR 1.01 [95% c.i. 1.004–1.02]; very low certainty of evidence). To enhance the practical applicability, door openings were categorised. Inconclusive evidence was found regarding SSI risk difference for 10 to 31.7 door openings per hour (OR 1.11 [95% c.i. 0.77–1.59]) compared to 10 or fewer. While for more than 31.7 door openings per hour (OR 1.52 [95% c.i. 1.02–2.26]) a conclusive difference in SSI risk was found compared to 10 or fewer. Interpretation Very low certainty of evidence indicated a marginal increase in SSI risk for each extra door opening per hour. However, a restriction on the number of door openings in the OR to a maximum of 10 per hour has little to no effect on SSI risk. Funding This systematic review is funded by the Dutch Stichting Kwaliteitsgelden Medisch Specialisten (SKMS, Foundation Quality Funds Medical Specialists).