Design and analysis of outcomes following SARS-CoV-2 infection in veterans.

BACKGROUND: Understanding how SARS-CoV-2 infection impacts long-term patient outcomes requires identification of comparable persons with and without infection. We report the design and implementation of a matching strategy employed by the Department of Veterans Affairs' (VA) COVID-19 Observational Research Collaboratory (CORC) to develop comparable cohorts of SARS-CoV-2 infected and uninfected persons for the purpose of inferring potential causative long-term adverse effects of SARS-CoV-2 infection in the Veteran population. METHODS: In a retrospective cohort study, we identified VA health care system patients who were and were not infected with SARS-CoV-2 on a rolling monthly basis. We generated matched cohorts within each month utilizing a combination of exact and time-varying propensity score matching based on electronic health record (EHR)-derived covariates that can be confounders or risk factors across a range of outcomes. RESULTS: From an initial pool of 126,689,864 person-months of observation, we generated final matched cohorts of 208,536 Veterans infected between March 2020-April 2021 and 3,014,091 uninfected Veterans. Matched cohorts were well-balanced on all 39 covariates used in matching after excluding patients for: no VA health care utilization; implausible age, weight, or height; living outside of the 50 states or Washington, D.C.; prior SARS-CoV-2 diagnosis per Medicare claims; or lack of a suitable match. Most Veterans in the matched cohort were male (88.3%), non-Hispanic (87.1%), white (67.2%), and living in urban areas (71.5%), with a mean age of 60.6, BMI of 31.3, Gagne comorbidity score of 1.4 and a mean of 2.3 CDC high-risk conditions. The most common diagnoses were hypertension (61.4%), diabetes (34.3%), major depression (32.2%), coronary heart disease (28.5%), PTSD (25.5%), anxiety (22.5%), and chronic kidney disease (22.5%). CONCLUSION: This successful creation of matched SARS-CoV-2 infected and uninfected patient cohorts from the largest integrated health system in the United States will support cohort studies of outcomes derived from EHRs and sample selection for qualitative interviews and patient surveys. These studies will increase our understanding of the long-term outcomes of Veterans who were infected with SARS-CoV-2.

Unintended Consequences of COVID-19 Social Distancing Among Older Adults With Kidney Disease.

BACKGROUND: While social distancing policies protect older adults with advanced chronic kidney disease (CKD) from exposure to COVID-19, reduced social interaction may also have unintended consequences. METHODS: To identify subgroups of patients at risk for unintended health consequences of social distancing, we conducted a cross-sectional analysis of data from a national cohort study of older veterans with advanced CKD (n = 223). Characteristics included activities of daily living (ADLs), instrumental ADLs (IADLs), cognition score, depression score, social support, financial stress, symptom burden, and number of chronic conditions. Unintended consequences of social distancing included restricted Life Space mobility, low willingness for video telehealth, reduced in-person contact with caregivers, and food insecurity. We identified subgroups of patients at risk of unintended consequences using model-based recursive partitioning (MoB). RESULTS: Participants had a mean age of 77.9 years, 64.6% were white, and 96.9% were male. Overall, 22.4% of participants had restricted Life Space, 33.9% reported low willingness for video telehealth, 19.0% reported reduced caregiver contact, and 3.2% reported food insecurity. For Life Space restriction, 4 subgroups partitioned (ie, split) by IADL difficulty, cognition score, and ADL difficulty were identified. The highest rate of restricted Life Space was 54.7% in the subgroup of participants with >3 IADL difficulties. For low willingness for telehealth and reduced caregiver contact, separate models identified 2 subgroups split by cognition score and depression score, respectively. CONCLUSIONS: Measures of function, cognition, and depressive symptoms may identify older adults with advanced CKD who are at higher risk for unintended health consequences of social distancing.