Assessing the role of geographical access to health-care in colorectal cancer diagnosis and survival in Scotland

Abstract

Geographical accessibility to healthcare services is important for the achievement of health equity. Lack of spatial access can result in delayed medical treatment and poor health outcomes. In this research, individual level data are used to assess how geographical accessibility to healthcare influences cancer diagnosis and survival in Scotland. Specifically, this thesis aims to address the following three research questions:

• How does geographical accessibility to healthcare services vary according to area characteristics? • Is geographical accessibility to cancer treatment hospitals associated with rates of colorectal cancer survival? • Is geographical accessibility to General Practitioners (GPs) associated with the stage of diagnosis for colorectal cancer?

To address the above research questions, this thesis develops a new Geographic Information System (GIS) measure of distance and time to health services at a fine-scale geography (i.e., postcode level) in Scotland. Three other major datasets are innovatively linked with the GIS- based accessibility measure to explore colorectal cancer diagnosis and survival in the Scottish context; these are the Scottish Longitudinal Study, NHS National Services Scotland, and Scottish Government data. This research found significant variation in travel time to GP and hospitals in Scotland at postcode level. After controlling for rurality, there is an area-level social gradient in distance to health services. Using survival analysis modelling and controlling for other social, demographic and economic correlates of diagnosis and survival for colorectal cancer, this thesis found that travel time to health services has no influence on colorectal cancer diagnosis or survival in Scotland. Unlike many previous studies, this study controlled for individual correlates of social circumstances. Early diagnosis, screening and having early treatment were found to be significant in determining cancer survival. The use of individual level data and the linkage of four major national datasets have opened new avenues for future health research to test hypotheses about geographical accessibility in other cancers.