Diagnosing acute coronary syndrome in telephone triage: does it matter who initially calls? A cross-sectional study.

Background: Adequate triage of patients with symptoms suggestive of ACS is crucial. Considering who calls might be useful to improve telephone triage of these patients. In this article, we aim to assess whether a call made by a surrogate is related to urgency allocation or higher odds of an acute coronary syndrome (ACS) than patient-initiated calls, and to assess possible gender differences.

Methods: Cross-sectional study of patients with symptoms suggestive of ACS who called the out-of-hours service in primary care (OHS-PC). Calls were classified into "patient-initiated call" or "surrogate call". Call and patient characteristics were collected. Odds ratios (OR) were calculated for the relationship between the type of call and (i) urgency allocation, (ii) ACS, and (iii) ACS or other life-threatening event, stratified for gender.

Results: In total 2,428 recordings were included for analysis. Around half of the recordings were surrogate calls, and these more often received a high urgency (80.0%) than patient-initiated calls (57.8%), OR 2.92 (95%CI 2.44-3.50); in women OR 3.46, (95%CI 2.70-4.45), in men OR 2.42 (95%CI 1.86-3.16). Of all participants, 11.0% were diagnosed with an ACS; in women 8.0%, in men 14.7%. In the surrogate call group this was 14.4%, in the patient-initiated call group 7.6%; OR 2.04 (95%CI 1.57-2.67). In women, the OR was 2.46 (95%CI 1.63-3.77), in men 1.69 (95%CI 1.20-2.41).

Conclusions: Compared to patients who call themselves, surrogate calls on behalf of a patient with symptoms suggestive of ACS receive more often a high urgency, and these patients have a risk twice as high of an ACS, an effect similar in women and men. It is useful for triage at the OHS-PC to consider who calls if it concerns a patient with symptoms suggestive of ACS.

Clinical trial number: NTR7331. Registration Date 26-06-2018.