CPR competence assessment in police first responders: a psychometric tool based on the COM-B model

This study developed and validated a theory-driven instrument to evaluate cardiopulmonary resuscitation (CPR) training outcomes among police first responders, who often arrive at out-of-hospital cardiac arrest scenes before emergency medical services. Guided by the Capability, Opportunity, Motivation–Behavior (COM-B) model, the instrument integrates these domains into a higher-order construct, CPR Behavior Change Potential (CBCP). A cross-sectional study was conducted with frontline police officers from three precincts in New Taipei City, Taiwan. A pilot phase (n = 117) was used for item refinement, followed by formal validation with 207 participants who completed 15 attitudinal items and 10 CPR knowledge items. Objective CPR performance indicators, including compression depth and rate, were measured using a quality CPR (QCPR) feedback-enabled simulator. Psychometric evaluation included exploratory and confirmatory factor analysis and item response theory. The results demonstrated strong reliability (α = 0.88–0.94; KR-20 = 0.95) and acceptable model fit, with the three first-order domains converging into CBCP (target coefficient = 0.774). Skill self-efficacy showed a moderate association with compression depth (r = 0.31, P < 0.01), supporting criterion validity. This validated instrument provides a practical, evidence-informed tool for assessing CPR training readiness among police officers and supports targeted retraining strategies and organizational decision-making aligned with Sustainable Development Goal 3.