Using data analysis and mathematical modelling to study tuberculosis contact tracing in London, with reference to the national strategy and guidance

Background: In January 2015, Public Health England and NHS England published a collaborative TB strategy for the years 2015-20; this strategy highlighted contact tracing as a key element. In January 2016, the National Institute of Health and Care Excellence (NICE) made changes to the UK TB guidance, including no longer recommending that contacts of non-pulmonary TB cases be screened. This thesis attempts to address several issues arising from these policy documents. Methods: I utilized a range of quantitative approaches. I undertook a cohort analysis of TB cases in London between 2012-15 (inclusive), including logistic regression, to understand contact tracing outcomes in London, and how these differed between population subgroups. To understand the impact of changes to NICE guidance I carried out an economic analysis using a simple static model. I then utilized a pairwise transmission model to understand how transmission differs between those with primary and reactivation disease. Results: In London from 2012-15, 91% of pulmonary index cases had at least one contact identified (a median of four per case), and 86% of these identified contacts were evaluated. In this period, 80% of those contacts determined ... (continues)