Understanding the population, health system resource and access effects of colorectal cancer screening in Nova Scotia using simulation modelling

Colorectal cancer (CRC) is a very common cancer in Canada. It is second only to lung cancer as a leading cause of cancer death. While the number of new cases of CRC stabilised in Canada between 1994 and 2003, this trend has not been observed in Nova Scotia (NS). Survival of CRC is improved by early diagnosis and access to effective therapies, as it is highly treatable if detected and treated early. NS is now implementing a province-wide screening program. This research will study the effects of CRC screening on the health of the population and the health care system. Evaluating the effect of CRC screening is a highly complex process in which many population and health system elements must be measured. Four main question areas must be considered: 1) What are the effects of current screening programs on the number of cases of CRC and death rates? 2) How do changes in numbers of cases, treatment, screening tests and attendance rates modify screening effects? 3) What are the effects of different screening strategies on CRC rates, death rates, wait times, need for services and costs? 4) Is mass screening justified in terms of costs vs. benefits? Addressing these questions is possible by means of simulation modelling, in which the actions of the individual units that make up the system are replicated in a computer model. Simulation modelling is a powerful tool, and particularly useful for examining complex systems such as CRC where intervention studies are not feasible due to the complexity of the factors involved and the need for long follow-up to observe the relevant outcomes. The results of this study will directly benefit Nova Scotians and the health care system by determining the most effective means of delivering CRC care, from screening and treatment through to end of life care, while identifying issues of access, equity and quality of services. The results will also be very useful to other provinces wishing to study CRC care programs.