Mortality Among Solid Organ Waitlist Candidates During COVID-19 in the United States

Jonathan Miller; Andrew Wey; Donald Musgrove; Yoon Son Ahn; Allyson Hart; Bertram L. Kasiske; Ryutaro Hirose; Ajay K. Israni; Jon J. Snyder

Disclosures

American Journal of Transplantation. 2021;21(6):2262-2268. 

In This Article

Abstract and Introduction

Abstract

We examined the effects of COVID-19 on solid organ waiting list mortality in the United States and compared effects across patient demographics (e.g., race, age, and sex) and donation service areas. Three separate piecewise exponential survival models estimated for each solid organ the overall, demographic-specific, and donation service area-specific differences in the hazard of waitlist mortality before and after the national emergency declaration on March 13, 2020. Kidney waiting list mortality was higher after than before the national emergency (adjusted hazard ratio [aHR], 1.37; 95% CI, 1.23–1.52). The hazard of waitlist mortality was not significantly different before and after COVID-19 for liver (aHR, 0.94), pancreas (aHR, 1.01), lung (aHR, 1.00), and heart (aHR, 0.94). Kidney candidates had notable variability in differences across donation service areas (aHRs, New York City, 2.52; New Jersey, 1.84; and Michigan, 1.56). The only demographic group with increased waiting list mortality were Blacks versus Whites (aHR, 1.41; 95% CI, 1.07–1.86) for kidney candidates. The first 10 weeks after the declaration of a national emergency had a heterogeneous effect on waitlist mortality rate, varying by geography and ethnicity. This heterogeneity will complicate comparisons of transplant program performance during COVID-19.

Introduction

The coronavirus disease 2019 (COVID-19) pandemic continues to affect healthcare systems worldwide, including solid organ transplant systems. Recent studies have described substantial decreases in rates of transplant during the pandemic.[1] While the incidence of and mortality due to COVID-19 among solid organ transplant candidates and recipients has not yet been described in the United States, the cumulative incidence rate of COVID-19 among solid organ waitlist candidates in the United Kingdom was 3.8% through May 20, 2020, with an all-cause mortality rate of 10.2% among those who developed COVID-19.[2] This was substantially higher than overall population case-fatality rates, which have been estimated at 1%–6%,[3–5] emphasizing the importance of understanding the effect of COVID-19 on the solid organ candidate population in the United States.

The Scientific Registry of Transplant Recipients (SRTR) reports on waiting list outcomes in our Program-Specific Reports (PSRs). Because COVID-19 may lead to worse outcomes for patients listed at transplant programs in regions with more severe outbreaks, reported waitlist mortality rate ratios for such programs may be worse in PSRs due to COVID-19 rather than differences in clinical care. That is, COVID-19 may confound waitlist mortality rate ratios and corresponding evaluations (e.g., the 5-tier rating system for waitlist mortality used by both insurers and patients). The geographic variability of differences before and after COVID-19 can measure the potential risk of confounding in the waitlist mortality rate ratio. If the relative waitlist mortality rates in parts of the United States are considerably higher after COVID-19 than before, the risk of confounding due to COVID-19 is high, especially if the areas experienced relatively severe outbreaks.

This study investigated early trends in waitlist mortality rates before and after the emergence of COVID-19 among organ transplant candidates in the United States. It aimed to answer three questions of interest to the transplant system:

  1. Did the hazard of waitlist mortality differ before and after the COVID-19 national emergency declaration?

  2. If so, did the difference in the hazard of waitlist mortality vary geographically across the United States? Donation service areas (DSAs) were the geographic areas because they were granular enough to separate major metropolitan areas. For example, state-level variability would obscure potential differences in California, while DSA-level variability would capture differences across, for example, San Francisco, Los Angeles, and San Diego.

  3. Did the difference in the hazard of waitlist mortality vary across population subgroups?

This study was conducted as a part of a broad SRTR analysis of the impact of COVID-19 on solid organ transplantation in the United States (https://www.srtr.org/reports-tools/covid-19-evaluation/). The SRTR COVID-19 evaluation provides monthly updates of waitlist mortality, focusing on geographic and demographic differences, as the pandemic waxes and wanes across the United States.

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