Lyndon James Defends Dissertation

Lyndon James, doctoral student in Health Policy concentrating in Decision Science, successfully defended his thesis, “Enhancing Health Policy Decisions in Diseases Affecting Disadvantaged Populations: Applied and Methodological Analyses.” His dissertation committee was chaired by CHDS faculty Nicolas Menzies and included Theodore Cohen, Molly Franke and CHDS’ Ankur Pandya.

James employed three different analytic lenses to improve health policy decisions. Each chapter focuses on either Rifampicin-resistant Tuberculosis (RR-TB) or Sickle Cell Disease, both of which mainly affect systematically disadvantaged populations. Chapters one & two both focus on Rifampicin-resistant TB in Moldova. For this analysis, James built a microsimulation model to estimate the quality-adjusted life expectancy and costs of a six month, four-drug “BPaLM” regimen versus the current standard of care of nine-to-eighteen month regimens. Compared to longer regimens, he found that six months of the four-drug regimen was cost-effective across a broad range of scenarios and would save Moldova’s national TB program $7.1 million over five years. Broadly, the six-month, four-drug regimen would also be beneficial with respect to duration of TB disease resistant to key drugs, and lifetime cumulative incidence of acquired drug resistance.

In chapter two, James compared the effectiveness of all-oral regimens containing Bedaquiline against injectable containing regimens, using routinely collected electronic medical records in Moldova. In intention-to-treat analyses, he found that all-oral regimens with Bedaquiline were associated with a higher likelihood of culture conversion in the six months following the initiation of treatment. He noted that these results add to a growing evidence base in favor of shorter regimens for rifampicin-resistant TB, alongside other empirical and modeling evidence on the tolerability, long-term health outcomes, and cost-effectiveness of these regimens.

For his third chapter, James explored the impact of methodological decisions within distributional cost-effectiveness analysis (DCEA) using an example in Sickle Cell Disease. DCEA is a modeling approach capable of balancing concerns for efficiency and equity, by giving extra priority to groups who are less well-off. Although interest is growing in applying these methods, guidance for conducting DCEA in the US setting is limited. James modeled the US population in 2023 and showed that the choice of variables used to stratify the population into equity-relevant groups can affect whether a new Sickle Cell gene therapy would be recommended, even while holding the level of inequality aversion constant. He noted that this work highlights the need for awareness of the implications of modeling decisions in DCEA, and for consensus on how these analyses are conducted in the US.

Learn more: Read the publication, Impact and Cost-Effectiveness of the 6-Month BPaLM Regimen for Rifampicin-resistant Tuberculosis: A Mathematical Modeling Analysis
Learn more: Read the publication, Distributional Cost-Effectiveness of Equity-Enhancing Gene Therapy in Sickle Cell Disease in the United States