Researching COVID to enhance recovery (RECOVER) adult study protocol: Rationale, objectives and design (preprint)

Importance: SARS-CoV-2 infection can result in ongoing, relapsing, or new symptoms or other health effects after the acute phase of infection; termed post-acute sequelae of SARS-CoV-2 infection (PASC), or long COVID. The characteristics, prevalence, trajectory and mechanisms of PASC are ill-defined. The objectives of the Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC in Adults (RECOVER-Adult) are to: (1) characterize PASC prevalence; (2) characterize the symptoms, organ dysfunction, natural history, and distinct phenotypes of PASC; (3) identify demographic, social and clinical risk factors for PASC onset and recovery; and (4) define the biological mechanisms underlying PASC pathogenesis. Methods: RECOVER-Adult is a combined prospective/retrospective cohort currently planned to enroll 14,880 adults aged [≥]18 years. Eligible participants either must meet WHO criteria for suspected, probable, or confirmed infection; or must have evidence of no prior infection. Recruitment occurs at 86 sites in 33 U.S. states, Washington, DC and Puerto Rico, via facility- and community-based outreach. Participants complete quarterly questionnaires about symptoms, social determinants, vaccination status, and interim SARS-CoV-2 infections. In addition, participants contribute biospecimens and undergo physical and laboratory examinations at approximately 0, 90 and 180 days from infection or negative test date, and yearly thereafter. Some participants undergo additional testing based on specific criteria or random sampling. Patient representatives provide input on all study processes. The primary study outcome is onset of PASC, measured by signs and symptoms. A paradigm for identifying PASC cases will be defined and updated using supervised and unsupervised learning approaches with cross-validation. Logistic regression and proportional hazards regression will be conducted to investigate associations between risk factors, onset, and resolution of PASC symptoms. Discussion: RECOVER-Adult is the first national, prospective, longitudinal cohort of PASC among US adults. Results of this study are intended to inform public health, spur clinical trials, and expand treatment options.

Higher Hospitalization and Mortality Rates Among SARS-CoV-2 infected Persons in Rural America (preprint)

IMPORTANCERural communities are among the most underserved and resource-scarce populations in the United States (US), yet there are limited data on COVID-19 mortality in rural America. Furthermore, rural data are rarely centralized, precluding comparability across urban and rural regions. OBJECTIVEThe purpose of this study is to assess hospitalization rates and all-cause inpatient mortality among persons with definitive COVID-19 diagnoses residing in rural and urban areas. DESIGN, SETTINGS, AND PARTICIPANTSThis retrospective cohort study from the National COVID Cohort Collaborative (N3C) examines a cohort of 573,018 patients from 27 US hospital systems presenting with SARS-CoV-2 infection between January 2020 and March 2021, of whom 117,897 were hospitalized. A sample of 450,725 hospitalized persons without COVID-19 diagnoses was identified for comparison. EXPOSURESZIP Codes provided by source hospital systems were classified by urban-rural gradient through a crosswalk to the US Department of Agriculture Rural-Urban Commuting Area Codes. MAIN OUTCOMES AND MEASURESPrimary outcomes were hospitalization and all-cause mortality among hospitalized patients. Kaplan-Meier analysis and mixed effects logistic regression were used to estimate 30-day survival in hospitalized patients and associations between rurality, hospitalization, and inpatient mortality while controlling for major risk factors. RESULTSRural patients were more likely to be older, white, have higher body mass index, and diagnosed with SARS-CoV-2 later in the pandemic compared with their urban counterparts. Rural compared with urban inhabitants had higher rates of hospitalization (23% vs. 19%) and all-cause mortality among hospitalized patients (16% vs. 11%). After adjustment for demographic and baseline differences, rural residents (both urban adjacent and non-adjacent) with COVID-19 were more likely to be hospitalized (Adjusted Odds Ratio (AOR) 1.41, 95% Confidence Interval (CI), 1.37-1.45 and AOR 1.42, CI 1.35-1.50) and to die or be transferred to hospice (AOR 1.62, CI 1.30-1.49 and 1.38, CI 1.30-1.49), respectively. Similar differences in mortality were noted for hospitalized patients without SARS-CoV-2 infection. CONCLUSIONSHospitalization and inpatient mortality are higher among rural compared with urban persons with COVID-19, even after adjusting for several factors, including age and comorbidities. Further research is needed to understand the factors that drive health disparities in rural populations. KEY POINTSO_ST_ABSQUESTIONC_ST_ABSDo mortality and hospitalization rates among rural SARS-CoV-2 infected patients in the United States differ from that of their urban counterparts? FINDINGSHospitalization and mortality rates were significantly greater among rural compared with urban patients, even after adjusting for rural-urban differences including age and comorbidities. Similarly, in persons without SARS-CoV-2 infection, mortality rates were also higher among rural patients. MEANINGThese findings demonstrate a pervasive rural-urban discrepancy in all-cause inpatient mortality among rural individuals in the U.S. infected with SARS-COV-2 as well as among those who were uninfected. Further research is needed to understand factors driving health disparities among rural populations.