Missed Acute Coronary Syndrome During Telephone Triage at Out-of-Hours Primary Care: Lessons From A Case-Control Study

OBJECTIVES Serious adverse events at out-of-hours services in primary care (OHS-PC) are rare, and the most often concern is missed acute coronary syndrome (ACS). Previous studies on serious adverse events mainly concern root cause analyses, which highlighted errors in the telephone triage process but are hampered by hindsight bias. This study compared the recorded triage calls of patients with chest discomfort contacting the OHS-PC in whom an ACS was missed (cases), with triage calls involving matched controls with chest discomfort but without a missed ACS (controls), with the aim to assess the predictors of missed ACS. METHODS A case-control study with data from 2013 to 2017 of 9 OHS-PC in the Netherlands. The cases were matched 1:8 with controls based on age and sex. Clinical, patient, and call characteristics were univariably assessed, and general practitioner experts evaluated the triage while blinded to the final diagnosis or the case-control status. RESULTS Fifteen missed ACS calls and 120 matched control calls were included. Cases used less cardiovascular medication (38.5% versus 64.1%, P = 0.05) and more often experienced pain other than retrosternal chest pain (63.3% versus 24.7%, P = 0.02) compared with controls. Consultation of the supervising general practitioner (86.7% versus 49.2%, P = 0.02) occurred more often in cases than in controls. Experts rated the triage of cases more often as "poor" (33.3% versus 10.9%, P = 0.001) and "unsafe" (73.3% versus 22.5%, P < 0.001) compared with controls. CONCLUSIONS To facilitate learning from serious adverse events in the future, these should also be bundled and carefully assessed without hindsight bias and within the context of "normal" clinical practice.