A Nationwide Flash-Mob Study for Suspected Acute Coronary Syndrome

Purpose: Our primary objective was to evaluate the Marburg Heart Score (MHS), a clinical decision rule, or to develop an adapted clinical decision rule for family physicians (FPs) to safely rule out acute coronary syndrome (ACS) in patients referred to secondary care for suspected ACS. The secondary objective was to evaluate the feasibility of using the flash-mob method, an innovative study design, for large-scale research in family medicine.

Methods: In this 2-week, nationwide, prospective, observational, flash-mob study, FPs collected data on possible ACS predictors and assessed ACS probability (on a scale of 1-10) in patients referred to secondary care for suspected ACS.

Results: We collected data for 258 patients in 2 weeks by mobilizing approximately 1 in 5 FPs throughout the country via ambassadors. A final diagnosis was obtained for 243 patients (94.2%), of whom 45 (18.5%) received a diagnosis of ACS. Sex, sex-adjusted age, and ischemic changes on electrocardiography were significantly associated with ACS. The sensitivity of the MHS (cut-off ≤2) was 75.0%, specificity was 44.0%, positive predictive value was 24.3%, and negative predictive value was 88.0%. For the FP assessment (cut-off ≤5), these test characteristics were 86.7%, 41.4%, 25.2%, and 93.2%, respectively.

Conclusions: For patients referred to emergency care, ACS could not be safely ruled out using the MHS or FP clinical assessment. The flash-mob study design may be a feasible alternative research method to investigate relatively simple, clinically relevant research questions in family medicine on a large scale and over a relatively short time frame.