COVID-19 Vaccination Real Benefits in French Nursing Homes

Abstract

Introduction: COVID-19 vaccines efficacy is still underway in the nursing homes1-3 (NH), especially over time4. However, Electronic Health Records (EHR) provide low and efficient means of building cohort-studies5 as inside the Korian® group, specialized in care and support for fragile people. The objective of this medium-size cohort study is assessing COVID-19 vaccination rates and association with COVID-19 disease and history, hospitalization, emergency-call, fall and death.

Methods: We designed a multicenter, residents-based, prospective-retrospective cohort from EHRs, starting 01/04/2021, from the vaccination beginning over 17 weeks. We extracted all residents with clinical narratives throughout [12/21/2020 – 01/10/2021] and alive on 01/04/2021, over 60 years of age from 34 Korian® NH selected for their different sizes6, geographic locations but also their number stability over the first two months of 2021.

Results: Among 2000 alive on 01/04/2021, after 11 weeks of follow-up and 1461 (73.1%) vaccinated at least once, vaccination showed a significant effect on COVID-19 like-illness (OR = 0.75, 95% CI = [0.66 – 0.85]), hospitalizations (OR = 0.61, 95% CI = [0.52 – 0.71]), deaths (OR = 0.33, 95% CI = [0.26 – 0.41]) and emergency calls (OR = 0.70, 95% CI = [0.61 – 0.80]), but not on falls (OR = 1.06, 95% CI = [0.96 – 1.17]). 6 weeks later and 1631 (81.6%) vaccinated, the protective effect of vaccination fades over time: decreasing on COVID-19 like-illness (OR = 0.80, 95% CI = [0.70 – 0.90]), hospitalizations (OR = 0.74, 95% CI = [0.63 – 0.86]), deaths (OR = 0.38, 95% CI = [0.31 – 0.45]), emergency calls (OR = 0.88, 95% CI = [0.78 – 1.01]) and worsening on falls (OR = 1.28, 95% CI = [1.14 – 1.43]).

Conclusion: This EHR COVID-19 cohort showed vaccination effect fading over time but increasing survival and hospitalization delays, even with COVID-19 history.

Note:
Funding Information: No sources of funding were used to conduct this study or prepare this article.

Conflict of Interests: Tiba Delespierre has no competing interests that are directly relevant to the content of this article, except being a Korian® employee.

Ethical Approval: The study was authorized by The National Institute for Health Data (number INDS- MR 3109280520) and conducted in accordance with MR-004 reference methodology approved by the National Commission for Information Technology and Civil Liberties (French CNIL). In accordance with French legislation, formal approval from an ethics committee was not required for this type of retrospective non-interventional study based on the reuse of already recorded data.

Keywords: COVID-19 vaccination, electronic health records, COVID-19 like-illness, COVID-19 history, nursing home, survival modelization, Poisson and logistic regression, hospitalization, fall, emergency-call, deaths