LAUSR

Objective To evaluate the potential for change to costs from a decision to adopt a novel diagnostic pathway for referrals to cardiology outpatients with symptoms of chest pain. Design Costs modelling study using existing observational data, with a cost year of 2018. Setting Specialist Heart Centre in Singapore. Participants All new referrals (n=10 622) to the outpatient clinics for investigation between January 2017 and December 2017. Interventions Two competing testing regimes are compared in a decision tree model. Current practice includes classification of patients by their risk and the use of treadmill tests, calcium scores, functional testing and CT angiogram. New practice offers a fundamental difference in use of diagnostics for patients, with some offered angiogram directly and for low-risk patients a calcium score is used to refine risk stratification. Outcome measures The expected cost difference between testing alternatives. Results The expected cost saving from ‘New Practice’ as compared with ‘Current Practice’ is $S764 per patient. There is a 50% probability the savings per patient range between $S764 and $S824 and a 90% probability they are between $S616 and $S912. The expected savings to Singapore national health services are $S26.8 million annually, with a range of $S16.2 to $S41.1 million. Conclusions We find some evidence that using a coronary calcium score, which can be performed with a fraction of the time and cost of a CT coronary angiogram, saves costs to health services.