Prehospital Translation of Chest Pain Tools (RESCUE Study): Completion Rate and Inter-rater Reliability.

INTRODUCTION: Chest pain is a common reason for ambulance transport. Acute coronary syndrome (ACS) and pulmonary embolism (PE) risk assessments, such as history, electrocardiogram, age, risk factors (HEAR); Emergency Department Assessment of Chest Pain Score (EDACS); Pulmonary Embolism Rule-out Criteria (PERC); and revised Geneva score, are well validated for emergency department (ED) use but have not been translated to the prehospital setting. The objectives of this study were to evaluate the 1) prehospital completion rate and 2) inter-rater reliability of chest pain risk assessments. METHODS: We conducted a prospective observational cohort study in two emergency medical services (EMS) agencies (April 18, 2018 - January 2, 2019). Adults with acute, non-traumatic chest pain without ST-elevation myocardial infarction or unstable vital signs were accrued. Paramedics were trained to use the HEAR, EDACS, PERC, and revised Geneva score assessments. A subset of patients (a priori goal of N = 250) also had the four risk assessments completed by their treating clinicians in the ED, who were blinded to the EMS risk assessments. Outcomes were 1) risk assessments completion rate and 2) inter-rater reliability between EMS and ED assessments. An a priori goal for completion rate was set as >75%. We computed kappa with corresponding 95% confidence intervals (CI) for each risk assessment as a measure of inter-rater reliability. Acceptable agreement was defined a priori as kappa ≥ 0.60. RESULTS: During the study period, 837 patients with acute chest pain were accrued. The median age was 54 years, interquartile range 43-66, with 53% female and 51% Black. Completion rates for each risk assessment were above goal: the HEAR score was completed on 95.1% (796/837), EDACS on 92.0% (770/837), PERC on 89.4% (748/837), and revised Geneva score on 90.7% (759/837) of patients. We assessed agreement in a subgroup of 260 patients. The HEAR score had a kappa of 0.51 (95% CI, 0.41-0.61); EDACS was 0.60 (95% CI, 0.49-0.72); PERC was 0.71 (95% CI, 0.61-0.81); and revised Geneva score was 0.51 (95% CI, 0.39-0.62). CONCLUSION: The completion rate of risk assessments for ACS and PE was high for prehospital field personnel. The PERC and EDACS both demonstrated acceptable agreement between paramedics and clinicians in the ED, although assessments with better agreement are likely needed.

Multicenter, randomized trial of quantitative pretest probability to reduce unnecessary medical radiation exposure in emergency department patients with chest pain and dyspnea.

BACKGROUND: Use of pretest probability can reduce unnecessary testing. We hypothesize that quantitative pretest probability, linked to evidence-based management strategies, can reduce unnecessary radiation exposure and cost in low-risk patients with symptoms suggestive of acute coronary syndrome and pulmonary embolism. METHODS AND RESULTS: This was a prospective, 4-center, randomized controlled trial of decision support effectiveness. Subjects were adults with chest pain and dyspnea, nondiagnostic ECGs, and no obvious diagnosis. The clinician provided data needed to compute pretest probabilities from a Web-based system. Clinicians randomized to the intervention group received the pretest probability estimates for both acute coronary syndrome and pulmonary embolism and suggested clinical actions designed to lower radiation exposure and cost. The control group received nothing. Patients were followed for 90 days. The primary outcome and sample size of 550 was predicated on a significant reduction in the proportion of healthy patients exposed to >5 mSv chest radiation. A total of 550 patients were randomized, and 541 had complete data. The proportion with >5 mSv to the chest and no significant cardiopulmonary diagnosis within 90 days was reduced from 33% to 25% (P=0.038). The intervention group had significantly lower median chest radiation exposure (0.06 versus 0.34 mSv; P=0.037, Mann-Whitney U test) and lower median costs ($934 versus $1275; P=0.018) for medical care. Adverse events occurred in 16% of controls and 11% in the intervention group (P=0.06). CONCLUSIONS: Provision of pretest probability and prescriptive advice reduced radiation exposure and cost of care in low-risk ambulatory patients with symptoms of acute coronary syndrome and pulmonary embolism. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01059500.