Evolving impact of the COVID-19 pandemic in chronic dialysis recipients over the course of pandemic waves and COVID-19 vaccination rollout: a French national study. (preprint)

BackgroundThis observational study aims to assess the impact of the pandemic on the evolving of kidney transplantations, survival, and vaccination in chronic dialysis recipients (CDR) over the COVID-19 pandemic subperiods. MethodsUsing the French national health claims database, incident persons with end stage kidney disease in years 2015 to 2021 treated with dialysis were followed-up until December 31, 2022. Kidney transplantion and survival over pandemic subperiods versus the prepandemic period were investigated using longitudinal models with time-dependent covariates. Moreover, the impact of cumulative doses of COVID-19 vaccine on hospitalization and survival were compared between CDR and matched-control individuals. FindingsFollow-up of the 71,583 CDR and 143,166 controls totalized 639,341 person-years (CDR: 184,909; controls: 454,432). The likelihood of receiving a kidney transplant decreased during all pandemic subperiods except one. Mortality in CDR increased during the 3 wave subperiods (hazard ratio (HR [95% confidence interval]): 1{middle dot}19 [1{middle dot}13-1{middle dot}27], 1{middle dot}19 [1{middle dot}15-1{middle dot}23], and 1{middle dot}12 [1{middle dot}07-1{middle dot}17], respectively). While vaccine coverage declined with each booster dose, receiving such doses was associated with lower risks of COVID-19-related hospitalization (0{middle dot}66 [0{middle dot}56-0{middle dot}77], 0{middle dot}83 [0{middle dot}72-0{middle dot}94] for 1st booster versus 2nd dose and 2nd booster versus 1st booster, respectively) and death (corresponding HR: 0{middle dot}55 [0{middle dot}51-0{middle dot}59], 0{middle dot}88 [0{middle dot}83-0{middle dot}95]). Evolving patterns in mortality and vaccination outcomes were similar in CDR and controls. InterpretationThe impact of the pandemic in CDR was not specific of the kidney disease per se. Study results also suggest future research aimed at increasing adherence to vaccine booster doses.

Direct and indirect impact of the COVID-19 pandemic on the survival of kidney transplant recipients: a national observational study in France. (preprint)

Background During the pandemic period, healthcare systems were substantially reorganized for managing COVID-19 cases. The corresponding changes on the standard care of persons with chronic diseases and the potential consequences on their outcomes remain insufficiently documented. This observational study investigates the direct and indirect impact of the pandemic period on the survival of kidney transplant recipients (KTR), in particular in those not hospitalized for COVID-19. Methods We conducted a cohort study using the French national health data system which contains all healthcare consumptions in France. Incident persons with end stage kidney disease between January 1, 2015 and December 31, 2020 who received a kidney transplant were included and followed-up from their transplantation date to December 31, 2021. The survival of KTR during the pre-pandemic and pandemic periods was investigated using Cox models with time-dependent covariates, including vaccination and hospitalization events. Findings There were 10,637 KTR included in the study, with 324 and 430 deaths observed during the pre-pandemic (15,115 person-years of follow-up) and pandemic periods (14,657 person-years of follow-up), including 127 deaths observed among the 659 persons with a COVID-19-related hospitalization. In multivariable analyses, the risk of death during the pandemic period was similar to that observed during the pre-pandemic period (hazard ratio (HR) [95% confidence interval]: 0.92 [0.77-1.11]), while COVID-19-related hospitalization was associated with an increased risk of death (HR: 10.62 [8.46-13.33]). In addition, pre-emptive kidney transplantation was associated with a lower risk of death (HR: 0.71 [0.56-0.89]), as well as a third vaccine dose (HR: 0.42 [0.30-0.57]), while age, diabetes and cardiovascular diseases were associated with higher risks of death. Interpretation Considering persons living with a kidney transplant with no severe COVID-19-related hospitalization, the pandemic period was not associated with a higher risk of death.

Hospital admissions and mortality for acute exacerbations of COPD during the COVID-19 pandemic: a nationwide study in France (preprint)

Background: A global reduction in hospital admissions for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) was observed during the first months of the COVID-19 pandemic. Large-scale studies covering the entire pandemic period are lacking. We investigated hospitalizations for AECOPD and the associated in-hospital mortality at the national level in France during the first two years of the pandemic. Methods: We used the French National Hospital Database to analyse the time trends in (1) monthly incidences of hospitalizations for AECOPD, considering intensive care unit (ICU) admission and COVID-19 diagnoses, and (2) the related in-hospital mortality, from January 2016 to November 2021. Pandemic years were compared with the pre-pandemic years using Poisson regressions. Results: The database included 565,890 hospitalizations for AECOPD during the study period. The median age at admission was 74 years (interquartile range 65-83), and 37% of the stays concerned women. We found: (1) a dramatic and sustainable decline in hospitalizations for AECOPD over the pandemic period (from 8,899 to 6,032 monthly admissions, relative risk (RR) 0.65, 95% confidence interval (CI) 0.65-0.66), and (2) a concomitant increase in in-hospital mortality for AECOPD stays (from 6.2% to 7.6% per month, RR 1.24, 95% CI 1.21-1.27). The proportion of stays yielding ICU admission was similar in the pre-pandemic and pandemic years, 21.5% and 21.3%, respectively. In-hospital mortality increased to a greater extent for stays without ICU admission (RR 1.39, 95% CI 1.35-1.43) than for those with ICU admission (RR 1.09, 95% CI 1.05-1.13). Since January 2020, only 1.5% of stays were associated with a diagnosis of COVID-19, and their mortality rate was nearly 3-times higher than those without COVID-19 (RR 2.66, 95% CI 2.41-2.93). Conclusion: The decline in admissions for AECOPD during the pandemic could be attributed to a decrease in the incidence of exacerbations for COPD patients and/or to a possible shift from hospital to community care. The rise in in-hospital mortality is partially explained by COVID-19, and could be related to restricted access to ICUs for some patients and/or to greater proportions of severe cases among the patients hospitalized during the pandemic.