Participatory simulation modeling to inform colorectal cancer screening in a complex remote northern health system: Canada's Northwest Territories

BACKGROUND & AIMS Colorectal cancer (CRC) mortality in the Northwest Territories (NWT), a northern region of Canada, could be reduced by implementing a CRC screening program. However, this may require additional colonoscopy resources. We used participatory simulation modeling to predict colonoscopy demand and to develop strategies for implementing a feasible and effective CRC screening program in this complex remote northern health system. METHODS Using a participatory simulation modeling approach, we first developed a conceptual model of CRC screening with local collaborators. This approach informed our parameter adjustments of an existing microsimulation model, OncoSim-CRC, using data from a retrospective cohort review of CRC screening between 2014-2019 and secondary data. Model scenarios reflecting program implementation were run for 500 million cases. Validity was assessed, and outputs analyzed with collaborators. Alternative scenarios were developed to reduce colonoscopy demand and results were presented to end-users. RESULTS We estimated that colonoscopy demand with a CRC screening program phased-in over 5 years would surpass capacity within 2 years. If demand is met, screen-detected cancers would increase by 110 %, and clinically-detected cases would reduce by 26 % over the next 30 years. We also found that prolonging the phase-in period, or revising adenoma follow-up guidelines would reduce colonoscopy demand while still improving cancer detection. Both strategies were considered feasible by collaborators. The adjusted model was valid, and the projections informed local end-users plans for CRC screening delivery. CONCLUSIONS Using participatory simulation modeling, we projected that a screening program would improve CRC detection but surpass current colonoscopy capacity. Phasing-in the screening program and reducing endoscopic adenoma follow-up would enhance feasibility of a CRC screening program in the NWT and help maintain its effectiveness.