Career-Stage Differences in Reported Sharps Injury Circumstances: A Japan-EPINet Case-Case Analysis, 2004-2024

Circumstances of reported sharps injuries may differ by career stage and may also reflect occupation and assigned tasks.

We conducted a case-case analysis of 56,782 Japan-EPINet injury reports (2004-2024). We compared 17 circumstances between early-career (0 to <6 years) and experienced (10-60 years) health care workers (HCWs), accounting for clustering within facilities. Additional analyses adjusted for occupation, examined major occupations separately, and modeled experience continuously. A secondary classification analysis used logistic regression and permutation importance to assess which report characteristics distinguished the groups.

Among 44,342 reports with a classified circumstance, injuries reported by early-career HCWs more often involved recapping (9.9% vs 5.8%), disassembling a device (8.3% vs 4.7%), and events before patient use (6.3% vs 3.7%), and less often occurred during patient use (24.7% vs 32.0%; all q <.001). These differences remained significant after adjusting for occupation. Cramér V for the overall circumstance distribution was 0.144 (95% confidence interval, 0.133-0.157). In the all-features model (cross-validated area under the receiver operating characteristic curve, 0.783), injury circumstance made a modest contribution to classification.

Career-stage differences were evident within occupations, particularly in injuries involving recapping and device dismantling.

These findings support reviewing preparation, recapping, and device dismantling among early-career HCWs, alongside procedure-specific review of injuries during patient use.