Aernoud Fiolet

341 Accuracy of using routinely collected electronic healthcare data to identify cardiovascular endpoints Figure 1: Methods of endpoint data collection. *Not performed in this study. Abbreviation: EHR: Electronic healthcare record. Study design and population The LoDoCo2 trial was a multicenter, randomized, placebo-controlled, clinical trial investigating efficacy of low-dose colchicine in patients with coronary disease. Patients were recruited between August 2014 and December 2018. Methods and main results of the comparison trial were published before. 15,16 For the present study, patients recruited by four sites in the Netherlands were selected. The site selection was based on the total number of included trial participants and different EHR software vendors of the sites. The four selected sites used three different EHR software vendors: Epic Systems Corporation (https://www.epic.com ), Chipsoft (htttps://www.chipsoft.com ), and CSC Care solutions (https://www.easycare. software). These three EHR software vendors are used in 80% of Dutch hospitals, 40% of North American hospitals and 10% of all hospitals using EHRs globally. 17,18 Data collection For this study, EHR records were searched with a semi-automated EHR text- mining software program to identify the occurrences of any of the pre-defined trial endpoints. Semi-automated refers to the combination automatic detection and manual validation of the results. Endpoints reported in physical investigator- patient interviews during the original trial were used as reference standard. EHR data retrieval was performed with a commercially available software program (CTcue, version 2.0.12). The program indexes and searches through all structured and free-text EHR data entries. This included clinical notes, reports, diagnosis letters, laboratory measurements, imaging results and histopathology reports. Identification of endpoints was based on a pre-defined query that was developed by three authors (WD, PV and AF) using data from one site. The query consisted of terms and synonyms for all trial endpoints, and if applicable, blood measurements, drug use, and/or insurance codes. No site-specific optimizations were added to the