COVID-19 Infection Relative Risk Reduction Versus Absolute Risk Reduction Since 2020-2022 to 2023 and 2023 to 2024 in A General Medicine Office in Toledo (Spain)
Jose Luis Turabian
ABSTRACT
Background: The expression of the true impact of COVID-19 prevention measures in daily practice on the population can be confusing when presented as relative risk reduction (RRR) or absolute risk reduction (ARR).
Objective: To compare RRR with ARR of SARS-CoV-2 infections since 2020-2022 period to 2023 and since 2023 to 2024.
Methodology: Comparison of secondary data among COVID-19 infection cases in from 2020-2024 years of previous studies, all of them carried out in the same population of patients treated in a general medicine office in Toledo, Spain. 2020-2022 period was considered a control group compared to 2023 (intervention group; hybrid immunity: vaccination and/or infection); and 2023 was considered a control group for 2024.
Results: For all COVID-19 cases (>=14 years) from the period 2020-2022 [1, 2 or 3 doses vaccine (first booster) in fall-winter 2021-2022] to 2023, an RRR of 67% versus an RRA of 8% was found, and from 2023 to 2024 [Fourth dose (second booster) was inoculated in fall-winter 2022-2023, and Fifth dose (third booster) in fall-winter 2023-2024] an RRR of 25% and an RRA of 1%. For all the selected variables studied, the ARRs were always lower or at times equal to the RRRs both from the period 2020-2022 to 2023, and from 2023 to 2024, except for Socio-health workers and Presence of chronic diseases from 2020-2022 to 2023. The downward differences in the ARR versus the RRR were more striking from 2020-2022 to 2023 than from 2023 to 2024.
Conclusion: Expressing the risk reduction as RRR shows an exceptionally striking appearance of risk reduction that does not exist in its expression as ARR, especially in the first period of the COVID-19 pandemic. However, the evolution of the decrease in incidence that decreases the ARR, and the possible underreporting of cases must be taken into account. This underlines the importance of considering both the ARR and the RRR
