This is a summary, written by members of the CITF Secretariat, of:
Naylor KL, McArthur E, Dixon SN, Kwong JC, Thomas D, Balamchi S, Blake PG, Garg AX, Atiqazaaman M, Hladunewich MA, Levin A, Yeung A, Oliver MJ. Impact of study design on vaccine effectiveness estimates of two mRNA COVID-19 vaccine doses in patients with stage 5 chronic kidney disease. Kidney International. January 2023. DOI: 10.1016/j.kint.2023.01.009.
The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.
A CITF-funded study conducted by Dr. Matthew Oliver (University of Toronto) and his team revealed that estimates of vaccine effectiveness (VE) in individuals diagnosed with chronic kidney disease are consistent across three common study designs: test-negativeTest-negative studies, the gold standard for estimating VE, select cases and controls from among individuals who tested for SARS-CoV-2 and showed symptoms consistent with COVID-19. Cases are those who tested positive, while controls tested negative. This type of study requires access to information on symptoms at testing, which might not be always available. , pseudo-test-negativePseudo-test-negative studies are very similar, in that all participants get tested for SARS-CoV-2, but don’t necessarily show symptoms. , and cohort studiesCohort studies follow a group of individuals over time, with some eventually testing positive for SARS-CoV-2 (they become cases) and others who don’t test or test negative (they become controls). These studies are usually far more resource-intensive. . They range from 60-70% against SARS-CoV-2 infection and 72-84% against severe outcomes across all designs. These findings suggest that each study method is robust in assessing VE in this population.
- The adjusted VE of two doses of mRNA COVID-19 vaccine in patients diagnosed with chronic kidney disease was: 67% based on test-negative studies, 70% based on pseudo-test-negative studies and 60% based on cohort studies.
- Against severe outcomes (hospitalization or death), the adjusted VE of two doses of vaccine in patients diagnosed with chronic kidney disease was: 84% based on test-negative and pseudo-test-negative studies, and 72% based on cohort studies.
This study was conducted using administrative healthcare databases including 14,416 individuals diagnosed with stage 5 chronic kidney disease in Ontario as of December 2020. The test-negative design included 1,202 individuals, the pseudo-test-negative design 8,127 individuals and the cohort design 14,416 individuals.
Estimates of vaccine effectiveness were adjusted for age, sex, region, those living in a long-term care residence, number of SARS-CoV-2 tests performed in the 3 months prior to December 2020, comorbidities, and kidney function.