Objectives: Short-term peripheral venous catheter-associated bloodstream infections (PVC-associated BSI) are disregarded in the literature because of their relatively low incidence. No data are available on the association between PVC diameter size and the risk of PVC-associated BSI.

Methods: Using a prospective database, we performed an observational study at the University of Geneva Hospitals from 1 January 2020 to 31 December 2021, including all patients with a PVC. We used univariable and multivariable marginal Cox regression models for clustered data to investigate the association between catheter size and PVC-associated BSI. The main variable of interest 'catheter size' was forced into our multivariable models. Confounders, which are thought to influence the risk of PVC-associated BSI, were used as adjustment factors.

Results: A total of 206 804 PVCs were included. In all, 10 806 of 201 413 (5.4%), 80 274 of 201 413 (39.9%), 93 047 of 201 413 (46.2%) and 17 286 of 201 413 (8.6%) PVCs measured ≤16G, 18G, 20G and ≥22G, respectively. The univariable analysis showed that diameters of ≤16G were significantly associated with a higher risk of PVC-associated BSI (hazard ratio [HR] 4.52, 95% CI, 1.14-18.00). Multivariable models confirmed these results (HR 4.65, 95% CI, 1.19-18.20). Sensitivity analyses including PVC inserted only in 2021 (HR 4.80, 95% CI, 1.21-19.10), for dwell time >2 days (HR 3.67, 95% CI, 0.92-14.65) and only in adults (HR 3.97, 95% CI, 0.97-15.39) showed similar results.

Discussion: Larger PVC size may increase the risk of PVC-associated BSI. Diameter size should be considered when selecting PVCs to reduce the burden of PVC-associated BSI.