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The assessment of patients with suspected acute coronary syndrome (ACS) incorporates ECGs and serial cardiac troponin values.1 Some patients then undergo further investigations (eg, exercise stress test or invasive coronary angiography) with risks of adverse events. For patients with a pretest probability of ACS less than 2%, the benefits of testing may not outweigh the risks.2 Engaging patients in discussions about their risks reduces the number admitted or undergoing stress testing.3 However, limited research has assessed patients’ tolerance for missed events while considering the risks of further testing. We investigated patients’ tolerance for risk of a missed diagnosis of ACS.
This cross-sectional study used a convenience sample of adult patients (≥18) presenting with chest pain to an inner-city, publicly funded Emergency Department between December 2018 and July 2019. This study was approved by the institution’s ethics committee and patients provided written consent.
A research assistant administered a questionnaire (online supplemental file 1) to the participants, recording baseline demographic information, self-assessment of previous heart trouble and self-assessment of health. Participants were asked whether they would like to have input or whether they would prefer the doctor to make decisions around their assessment. The participant was then asked to consider the scenario in box 1. Patients were asked whether they would be willing to be discharged at various levels of risk. These risks were presented graphically and in text form. Information about the risks of missed events and testing was developed in consultation with a patient consumer group.
Imagine you have presented to emergency with chest pain. The doctor has done an ECG and taken blood tests and the results are normal. This means that it is unlikely that you are having a heart attack today but there is still a small risk you may have an event related to your heart over the next 30 days, including a heart attack or death. If additional tests were done and these were also normal, the risk would be lower. The additional tests do have some risks though. There is about a 2% risk that you could develop an abnormal heart rhythm or have a heart attack or stroke during testing or have an allergic reaction to the injection given during a CT scan. The doctor tells you that you can choose to be discharged from emergency or can stay in hospital to undergo further tests.
For the 125 participants, the average age was 55.9 years (SD=17.4), 72 (57.6%) were male and 49 (39.2%) reported a prior heart complaint. Health status was reported as excellent (n=8, 6.4%), above average (n=36, 28.8%), average (n=53, 42.4%) and below average (n=28, 22.4%). One hundred one participants (80.8%) wanted to be involved in decisions around their care. Sixty-four (51.2%) patients reported that they would be willing to be discharged only if their risk was <0.1%. Thirteen (10.4%) patients were willing to be discharged at 2% risk. The remainder of participants reported a range of risk levels (figure 1). While it was not included as an option on the questionnaire, 46 (36.8%) patients stated that they would not wish to be discharged unless there was a 0% risk of a 30-day event.
Approximately half the patients reported a very low acceptable risk for discharge (<0.1%) with high interpatient variability. This finding is in line with one previous study of patient risk tolerance that reported a mean risk threshold for a missed major adverse cardiac event of 1 in 736 (0.1%) if risk was presented numerically.4 In contrast, a second study reported a higher risk threshold for patients of 6.5%.5 Neither study provided patients with information on the risks of further assessment or treatment. The finding that over one-third of patients did not want to be discharged unless there was a 0% risk suggests that some patients have unrealistic expectations. Clinicians may need to ensure that patients understand that no option is risk free in medicine.
Most patients wanted to be involved in healthcare decisions. This supports the use of shared decision-making in chest pain assessment. Hess and colleagues reported that shared decision-making only required one additional minute of clinician time and resulted in patients opting more often to be treated as an outpatient.3 6
This study was limited by using a scenario-based survey conducted at a single site with a convenience sample. Prior research noted that patients’ reported risk tolerance varies depending on the method used to present risks.4 We attempted to minimise this limitation by presenting risks in multiple ways.
Risk tolerance varies widely across patients. Despite the risk of testing, few patients will accept a risk of missed ACS as high as 2%.
Patient consent for publication
Ethical approval to conduct the study was obtained from the Royal Brisbane and Women’s Hospital Research Ethics Committee (LNR/2019/QRBW/49876). Participants gave informed consent to participate in the study before taking part.
Handling editor Edward Carlton
Contributors All authors met the requirement for authorship. JHG, SW, WP and LC conceived of and designed the study. JHG and SW were involved in acquisition of data. JG analysed the data, JHG, SW, WP and LC assisted with interpretation of the data. JHG and SW drafted the work, and all authors revised the manuscript critically for important intellectual content.
Funding JHG is funded by an Advance Queensland Fellowship.
Competing interests The authors declare no competing interests related to this work. Outside of the current work, William Parsonage, Louise Cullen and Jaimi Greenslade have had research grants paid to their institution from Siemens Healthcare, Abbott Point of Care, and Beckman Coulter. Jaimi Greenslade is funded by an Advance Queensland Fellowship.
Provenance and peer review Not commissioned; internally peer reviewed.
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