Importance: Peripheral intravenous catheters (PVCs) are the most frequently used indwelling devices in hospitals worldwide. Peripheral intravenous catheter bloodstream infections (PVC-BSIs) are rare, but severe and preventable, adverse events.

Objective: To investigate the incidence of PVC-BSIs after changing the policy of routine PVC replacement every 96 hours to clinically indicated replacement.

Design, setting, and participants: This institution-wide, observational cohort study evaluated all patients hospitalized at a large university-affiliated hospital with 10 sites in Western Switzerland with a PVC insertion between January 1, 2016, and February 29, 2020.

Exposures: Peripheral intravenous catheters were routinely replaced every 96 hours until March 31, 2018 (baseline period). Between April 1, 2018, and October 15, 2019, PVCs were replaced if clinically indicated (intervention period). From October 16, 2019, PVCs were again routinely replaced every 96 hours (reversion period).

Main outcomes and measures: The PVC-BSI rates and PVC-BSI incidence rate ratios (IRRs) during each period.

Results: A total of 412 631 PVCs with documented catheter duration were included (164 331 patients; median [interquartile range] patient age, 51 [33-72] years; 88 928 [54.1%] female): 241 432 PVCs at baseline, 130 779 at intervention, and 40 420 at reversion. Eleven PVC-BSIs were observed during the baseline period, 46 during the intervention, and 4 during the reversion period. Although the monthly number of PVC-days remained stable during all study periods, the number of monthly inserted PVCs decreased during the intervention period. The number of PVCs still in place more than 4 or more than 7 days was higher during the intervention period compared with the baseline and reversion periods. A significantly increased IRR of PVC-BSIs was observed for the intervention period (IRR, 7.20; 95% CI, 3.65-14.22; P < .001) compared with baseline, whereas during the reversion period there was no significant increase (IRR, 1.35; 95% CI, 0.30 6.17; P = .69).

Conclusions and relevance: The results of this cohort study using a large, prospective surveillance database suggest that replacement of PVCs only when clinically indicated may be associated with an increased risk of PVC-BSI compared with routine replacement. Even if PVC-associated BSI is a rare event, the use of PVCs in most patients makes this outcome relevant.