Adapting the ScHARR cervical screening model workload model for Scotland.

Abstract

Over the past thirty years, the Scottish cervical cancer screening programme has faced number of changes, particularly in the recommended age range for standard screening, recommended routine recall intervals and the way of primary testing. The aim of this dissertation is to investigate the potential workload impact of these on-going changes by analysing the number of invitations sent, the number of HPV and cytology tests and the number of colposcopy referrals. The first part of this dissertation reviewed a number of model reports used a discrete event simulation (DES) as a tool to predict the future demand for a specific cancer screening service. The aim of this review is to explore the current advances of DES applied to help in guiding screening planning. A total of five papers met the predefined inclusion criteria. Colon cancer screening was the most frequently modelled services. The models were considerably different in problem conceptualization, input parameters used and the quality of the report and the model itself. However, the outcomes obtained and reported are likely to be helpful for the decision makers regarding screening planning. The second part constructed a DES model representing the previous and the current Scottish cervical screening pathway to provide insights into real-world workload in colposcopy and NHS HPV and cytology laboratories. The model was inputted with data from English HPV primary screening pilot and Scottish cervical screening programme. A probabilistic sensitivity analysis was undertaken on the base case and further uncertainties were examined using scenario analysis. Despite that the model outcomes and the overall results were underestimated, there is a satisfactory reflection of the expected trends regards the outcomes of interest.