Importance: Bloodstream infections (BSIs) associated with peripheral intravenous catheters (PIVCs) are rare but preventable adverse events. The association of dwell time with the risk of BSIs with PIVCs remains controversial.

Objective: To analyze the risk of BSIs during PIVC maintenance therapy.

Design, setting, and participants: In this observational cohort study, all patients hospitalized at Geneva University Hospitals with at least 1 PIVC insertion on the upper extremity (N = 371 061) between January 1, 2016, and February 29, 2020, were evaluated. Statistical analysis was performed from January 2023 to January 2025.

Exposure: At least 1 PIVC insertion on the upper extremity.

Main outcomes and measures: The primary outcome was BSIs with PIVCs; data were collected by prospective BSI surveillance. The daily risk of BSIs with PIVCs was analyzed using the hazard rate function by kernel-based methods. Multivariable logistic models were performed to evaluate the risk of BSIs with PIVCs comparing different cutoff values of dwell times (>3 vs ≤3 days, >4 vs ≤4 days, >5 vs ≤5 days, and >6 vs ≤6 days).

Results: A total of 371 061 PIVCs (median patient age, 63 years [IQR, 41-79 years]; 187 786 women [51%]) with documented catheter duration were included. A total of 140 178 PIVCs (38%) had a dwell time of 1 to 2 days, 119 252 (32%) had a dwell time of 3 to 4 days, and 111 631 (30%) had a dwell time of more than 4 days. The instantaneous risk of BSIs with PIVCs was low in the first 2 days of dwell time and increased rapidly thereafter. The risk of BSIs was significantly increased after 3 days of catheter maintenance (adjusted odds ratio [AOR], 13.55; 95% CI, 5.44-34.00). This risk was the highest after 3 days and remained increased thereafter (>4 days: AOR, 8.53; 95% CI, 4.47-16.28; >5 days: AOR, 5.38; 95% CI, 3.23-8.96; and >6 days: AOR, 7.63; 95% CI, 4.57-12.74).

Conclusions and relevance: In this cohort study of 371 061 PIVCs, dwell time was associated with the development of BSIs with PIVCs. After day 3, PIVC indication should be reviewed and PIVC replacement considered.