The effect of the COVID-19 health disruptions on breast cancer mortality for older women: a semi-Markov modelling approach

Public health measures necessitated by the COVID-19 pandemic have affected cancer pathways by halting screening, delaying diagnostic tests and reducing the numbers starting treatment. Specifically, this moves individuals from observed and treated pathways to unobserved and untreated pathways. We introduce a semi-Markov model that includes both, extending an industry-based multiple state model used for life and critical illness insurance. Our model includes events related to cancer diagnosis and progression based on publicly available population data for women aged 65–89 in England and on relevant medical literature. We quantify age-specific excess deaths, for a period up to 5 years, along with years of life expectancy lost and changes in cancer mortality by cancer stage. Our analysis suggests a 3–6% increase in breast cancer deaths, and a 4–6% increase in registrations of advanced breast cancer, robust under sensitivity analysis. This should be applicable to actuarial work in areas where longevity and advanced age morbidity affect healthcare, retirement and insurance.