The Impact of Diagnostic Assessment Programs on the Diagnosis and Treatment of Colon and Rectal cancers in a Single Payer System

Abstract

Introduction: To streamline the diagnostic and pre-treatment assessments for patients with colorectal cancer, specialised Diagnostic Assessment Programs (DAPs) were developed across the province of Ontario, Canada. We compared the performance of DAPs with usual care (non-DAPs). Methods: Patients with colorectal cancer diagnosed between 2014 and 2016 were identified from the Ontario Cancer Registry. Using administrative databases, we compared wait times, healthcare utilization, and overall survival between DAP and non-DAP patients. Results: A total 2,606/18,046 (14%) colorectal cancer patients attended a DAP for part of their diagnostic assessment. DAP patients were younger, lived closer to a DAP, had higher income, were more likely to have stage 2-3 disease (versus stage 1), had tumors in the rectum or rectosigmoid junction, and were less likely to have been an inpatient at the time of diagnosis [odds ratio 3.39 (2.68-4.29)]. DAP patients were more likely to receive diagnostic imaging before treatment, consultation with a medical oncologist or radiation oncologist, and chemotherapy or radiation compared with non-DAP patients. After adjusting for case mix, DAP patients had a time until treatment that was longer by 9.5 (7.4, 11.5) days, but better overall survival than non-DAP patients [hazard ratio 0.84 (0.75-0.94)]. A longer time from diagnosis until treatment was not associated with worse overall survival [hazard ratio 0.96 (0.93-1.00)]. Conclusion: Colorectal DAPs provide more comprehensive healthcare and are associated with better overall survival. Wait-times as efficiency metrics should be interpreted carefully, as this is affected by triaging or enhanced treatment planning that may promote improved outcomes.