Impact of health insurance type on access to vaccination and mortality due to COVID-19 on patients with cancer in Colombia: a cohort study

BACKGROUND: In Colombia, all paid workers earning minimum wage or higher contribute part of their salary for access to the national health-care system through a type of insurance called contributive plan, which supports the remaining low-income population that is enrolled on the subsidised plan. During the COVID-19 pandemic, Colombia documented high mortality rate in patients with cancer, with higher mortality among low-income patients, according to data from our national registry of COVID-19 infection in patients with cancer. The aim of this research was to establish the differential access to COVID-19 vaccination depending on health insurance type, and its impact on mortality due to COVID-19 infection. METHODS: A cohort study was conducted with data from the Colombian National Cancer and COVID-19 Registry. Data were collected between June 1, 2021, when COVID-19 vaccines became available for patients with cancer in Colombia, and Oct 31, 2021. Included patients were aged 18 years or older, had a diagnosis of a solid tumour, were receiving active treatment or on follow-up, and had a confirmed SARS-CoV-2 infection. The cumulative incidence of mortality in the vaccinated and unvaccinated cohorts was compared. The estimation of the effect was done through relative risk (RR), and a multivariate analysis (generalised linear model, binomial family) was then done to estimate the effect of the type of health insurance. FINDINGS: 896 patients were included. 470 (52%) were older than 60 years; 530 (59%) were women and 366 (41%) were men. 172 (19%) patients were vaccinated and 724 (81%) patients were not vaccinated (resulting in a ratio of 1:4). According to the type of health insurance, the vaccine was administered to 26 (12%) of 211 patients in the subsidised plan and to 146 (21%) of 685 patients in the contributive plan. The rate of vaccination according with socioeconomic status was 69 (16%) of 430 patients in the low-income group, 75 (23%) of 329 in middle-income group, and 12 (29%) of 42 in high-income group. The cumulative incidence of mortality for all causes was 17% (n=123) in the non-vaccinated cohort and 5% (n=8) in vaccinated cohort. The cumulative incidence of mortality per health-care insurance was 24% (n=50) in the subsidised plan and 12% (n=81) in the contributive plan. The adjusted RR for mortality was 3·4 (95% CI 1·7–6·8) in unvaccinated versus vaccinated patients, and 1·8 (1·3–2·4) in patients on the subsidised versus the contributive plan. INTERPRETATION: Patients on the subsidised health plan in Colombia had higher mortality due to COVID-19 infection and less access to vaccines than patients with a contributive plan. Strategies to promote COVID-19 vaccination for all patients with cancer should be strengthened, with implementation of special measures to improve care for the low-income population. FUNDING: None.