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1.
Preprint in English | medRxiv | ID: ppmedrxiv-22279868

ABSTRACT

ImportanceThe COVID-19 pandemic had a substantial impact on the overall rate of death in the United States during the first year. It is unclear whether access to comprehensive medical care, such as through the VA healthcare system, altered death rates compared to the US population. ObjectiveQuantify the increase in death rates during the first year of the COVID-19 pandemic in the general US population and among individuals who receive comprehensive medical care through the Department of Veterans Affairs (VA). DesignAnalysis of changes in all-cause death rates by quarter, stratified by age, sex race/ethnicity, and region, based on individual-level data. Hierarchical regression models were fit in a Bayesian setting. Standardized rates were used for comparison between populations. Setting and participantsGeneral population of the United States, enrollees in the VA, and active users of VA healthcare. Exposure and main outcomeChanges in rates of death from any cause during the COVID-19 pandemic in 2020 compared to previous years. ResultsSharp increases were apparent across all of the adult age groups (25 years and older) in both the general US population and the VA populations. Across all of 2020, the relative increase in death rates was similar in the general US population (RR: 1.20 (95% CI: 1.17, 1.22)), VA enrollees (RR: 1.20 (95% CI: 1.14, 1.29)), and VA active users (RR: 1.19 (95% CI: 1.14, 1.26)). Because the pre-pandemic standardized mortality rates were higher in the VA populations prior to the pandemic, the absolute rates of excess mortality were higher in the VA populations. Conclusions and RelevanceDespite access to comprehensive medical care, active users of the VA had similar relative mortality increases from all causes compared with the general US population. Factors that influenced baseline rates of death and that mitigated viral transmission in the community are more likely to have influenced the impact of the pandemic.

2.
Preprint in English | medRxiv | ID: ppmedrxiv-22275716

ABSTRACT

BackgroundLittle is known regarding the effectiveness of tixagevimab/cilgavimab in preventing SARS-CoV-2 infection in this population, particularly after the emergence of the Omicron variant. ObjectiveTo determine the effectiveness of tixagevimab/cilgavimab for prevention of SARS-CoV-2 infection and severe disease among immunocompromised patients. DesignRetrospective cohort study with propensity matching and difference-in-difference analyses. SettingU.S. Department of Veterans Affairs (VA) healthcare system. ParticipantsVeterans age [≥]18 years as of January 1, 2022, receiving VA healthcare. We compared a cohort of 1,848 patients treated with at least one dose of intramuscular tixagevimab/cilgavimab to matched controls selected from 251,756 patients who were on immunocompromised or otherwise at high risk for COVID-19. Patients were followed through April 30, 2022, or until death, whichever occurred earlier. Main OutcomesComposite of SARS-CoV-2 infection, COVID-19-related hospitalization, and all-cause mortality. We used cox proportional hazards modelling to estimate the hazard ratios (HR) and 95% CI for the association between receipt of tixagevimab/cilgavimab and outcomes. ResultsMost (69%) tixagevimab/cilgavimab recipients were [≥]65 years old, 92% were identified as immunocompromised in electronic data, and 73% had [≥]3 mRNA vaccine doses or two doses of Ad26.COV2. Compared to propensity-matched controls, tixagevimab/cilgavimab-treated patients had a lower incidence of the composite COVID-19 outcome (17/1733 [1.0%] vs 206/6354 [3.2%]; HR 0.31; 95%CI, 0.18-0.53), and individually SARS-CoV-2 infection (HR 0.34; 95%CI, 0.13-0.87), COVID-19 hospitalization (HR 0.13; 95%CI, 0.02-0.99), and all-cause mortality (HR 0.36; 95%CI, 0.18-0.73). LimitationsConfounding by indication and immortal time bias. ConclusionsUsing national real-world data from predominantly vaccinated, immunocompromised Veterans, administration of tixagevimab/cilgavimab was associated with lower rates of SARS-CoV-2 infection, COVID-19 hospitalization, and all-cause mortality during the Omicron surge.

3.
Preprint in English | medRxiv | ID: ppmedrxiv-22272555

ABSTRACT

ImportancePrevious studies have analyzed effectiveness of booster mRNA Covid-19 vaccination and compared it with 2-dose primary series for both Delta and Omicron variants. Observational studies that estimate effectiveness by comparing outcomes among vaccinated and unvaccinated individuals may suffer from residual confounding and exposure misclassification. ObjectiveTo estimate relative effectiveness of booster vaccination versus the 2-dose primary series with self-controlled study design Design, Setting and ParticipantsWe used the Veterans Health Administration (VHA) Corporate Data Warehouse to identify U.S. Veterans enrolled in care [≥]2 years who received the 2-dose primary mRNA Covid-19 vaccine series and a mRNA Covid-19 booster following expanded recommendation for booster vaccination, and who had a positive SARS-CoV-2 test during the Delta (9/23/2021-11/30/2021) or Omicron (1/1/22-3/1/22) predominant period. Among them, we conducted a self-controlled risk interval (SCRI) analysis to compare odds of SARS-CoV-2 infection during a booster exposure interval versus a control interval. Exposurescontrol interval (days 4-6 post-booster vaccination, presumably prior to gain of booster immunity), and booster exposure interval (days 14-16 post-booster vaccination, presumably following gain of booster immunity) Outcomes and MeasuresPositive PCR or antigen SARS-CoV-2 test. Separately for Delta and Omicron periods, we used conditional logistic regression to calculate odds ratios (OR) of a positive test for the booster versus control interval and calculated relative effectiveness of booster versus 2-dose primary series as (1-OR)*100. The SCRI approach implicitly controlled for time-fixed confounders. ResultsWe found 42 individuals with a positive SARS-CoV-2 test in the control interval and 14 in the booster exposure interval during Delta period, and 137 and 66, respectively, in Omicron period. For the booster versus 2-dose primary series, the odds of infection were 70% (95%CI: 42%, 84%) lower during the Delta period and 56% (95%CI: 38%, 67%) lower during Omicron. Results were similar for ages <65 and [≥]65 years in the Omicron period. In sensitivity analyses among those with prior Covid-19 history, and age stratification, ORs were similar to the main analysis. ConclusionsBooster vaccination was more effective relative to a 2-dose primary series, the relative effectiveness was consistent across age groups and was higher during the Delta predominant period than during the Omicron period.

4.
Preprint in English | medRxiv | ID: ppmedrxiv-22269360

ABSTRACT

BackgroundWe estimated vaccine effectiveness (VE) of mRNA vaccines among US Veterans during periods of Delta and Omicron variant dominance. Patients included in this study were largely 65 years or older (62,834, 55%), male (101,259, 88%), and non-Hispanic white (66,986, 58%). MethodsWe used SARS-CoV-2 laboratory test results to conduct a matched test-negative case-control study to estimate VE of three and two doses of mRNA vaccines against infection (regardless of symptoms), and a matched case-control study to estimate VE against COVID-19-related hospitalization and death. We estimated VE as (1-odds ratio) x 100%. Severity of disease was measured using hospital length of stay (LOS) and admission to an intensive care unit (ICU). ResultsAgainst infection, booster doses had 7-times higher VE - 59% (95% confidence interval [CI], 57 to 61) - than 2-dose VE (7%; 95% CI, 3 to 10) during the Omicron period. For the Delta period, estimated VE against infection was 90% (95% CI, 88 to 92) among boosted vaccinees, 64% higher than VE among 2-dose vaccinees [55% (95% CI, 51 to 58)]. Against hospitalization, booster dose VE was 87% (95% CI, 80 to 91) during Omicron and 95% (95% CI, 91 to 97) during Delta; the 2-dose VE was 44% (95% CI, 26 to 58) during Omicron and 75% (95% CI, 70 to 80) during Delta. Against death, estimated VE with a booster dose was 94% (95% CI, 85 to 98) during Omicron and 96% (95% CI, 88 to 99) during Delta, while the 2-dose VE was 75% (95% CI, 52 to 87) during Omicron and 93% (95% CI, 85 to 97) during Delta. During the Omicron period, average hospital LOS was 4 days shorter [3 days (95%CI, 3 to 4 days)] than during the Delta period. ConclusionsA mRNA vaccine booster is more effective against infection, hospitalization, and death than 2-dose vaccination among an older male population with comorbidities.

5.
Preprint in English | medRxiv | ID: ppmedrxiv-21264194

ABSTRACT

BackgroundWith over 40 million cases of SARS-CoV-2 infection reported in the US and discussion of both vaccine mandates as well as boosters ongoing, we aim to examine protection conferred by previous infection compared with vaccination so that citizens and policy makers can make informed decisions. ObjectivesTo compare mRNA COVID-19 vaccine-induced immunity against immunity induced by previous infection with SARS-CoV-2 between June and August 2021 when the Delta variant became dominant in the US. We conducted a retrospective observational study comparing two groups whose incident vaccination or infection occurred within the first two months of 2021: (1) SARS-CoV-2-naive individuals who received a full mRNA vaccination - 2 doses of either Pfizer or Moderna vaccine, (2) newly infected individuals who were subdivided into those have not been vaccinated and those have been vaccinated after their infection. Matched multivariable Cox proportional hazards model was applied. We evaluated laboratory (RT-PCR) confirmed SARS-CoV-2 infection during follow-up, COVID-related hospitalization, and deaths. SettingVeterans Health Administration (VHA). Main outcomesPositive SARS-CoV-2 PCR test, COVID-related hospitalization, and deaths. Protection was estimated from hazard ratios with 95% confidence intervals (CI). ResultsA total of 9,539 patients with SARS-CoV-2 infection during the first two months of 2021 were matched to 14,458 and 23,105 patients fully vaccinated with Moderna and Pfizer mRNA vaccines, during the same two months. 3,917 (41%) of patients with SARS-CoV-2 infection were subsequently vaccinated. We plan to study this group separately. Consequently, protections were estimated among those with infection but were not subsequently vaccinated and those vaccinated with a mRNA vaccine. Among seniors, Moderna and Pfizer mRNA vaccines offered stronger protection against infection, lowering the risk by an additional 66% [HR: 0.34 (95% CI, 0.14-0.78)] and 68% [HR: 0.32 (95% CI, 0.14-0.70)]; stronger protection against hospitalization, lowering the risk by an additional 61% [HR: 0.34 (95% CI, 0.14-0.78)] and 45% [HR: 0.34 (95% CI, 0.14-0.78)]; and stronger protection against deaths lowering the risk by an additional 95% [HR: 0.05 (95% CI, 0.004-0.62)] and 99% [HR: 0.01 (95% CI, 0.001-0.44)]. Among young adults (age < 65), the protections offered by vaccines were statistically equivalent to that provided by previous infection, especially in terms of absolute incidence rate. ConclusionsAmong the elderly (age 65 or older), two-dose mRNA vaccines provided stronger protection against infection, hospitalization, and death, compared to natural immunity. Among young adults (age < 65), the protections offered between natural immunity and vaccine-induced immunity were similar.

6.
Preprint in English | medRxiv | ID: ppmedrxiv-21258906

ABSTRACT

ImportanceThe effectiveness of mRNA vaccination in a large and diverse American population, with older age and higher co-morbidity has not been assessed. ObjectiveTo describe the scope of the mRNA vaccination rollout among the diverse U.S. Veterans population, and to study the mRNA COVID-19 vaccine effectiveness (VE) against infection, symptomatic disease, hospitalization, and death. MethodsVaccination histories were obtained from medical records to determine if patients tested for SARS-CoV-2 were unvaccinated, partially vaccinated (first dose of mRNA COVID-19 vaccine), or fully vaccinated (two doses) at time of testing. First, coverage with any COVID-19 vaccination was described for all Veterans enrolled in Veterans Health Administration (VHA). Second, to evaluate VE, a matched test-negative case-control evaluation was conducted utilizing SARS-CoV-2 positive (cases [n=16,690]) and SARS-CoV-2 negative (controls [n=61,610]) tests from Veterans aged [≥]18 years old who routinely sought care at a VHA facility and were tested from December 14, 2020, through March 14, 2021. VE was calculated from odds ratios (ORs) with 95% confidence intervals (CI). ResultsBy March 7, 2021, among 6,170,750 Veterans, 1,547,045 (23%) received at least one COVID-19 vaccination. mRNA COVID-19 VE against infection, regardless of symptoms, was 94% (95% CI 92-95) and 58% (95%CI 54-62) for full and partial vaccination (vs. no vaccination), respectively. VE against infection was similar across subpopulations, and it was not significantly different from VE against symptomatic disease. VE against COVID-19-related hospitalization and death for full vs. no vaccination was 89% (95%CI 81-93) and 99% (95%CI 87-100), respectively. Conclusions and RelevanceThe VHAs efficient and equitable distribution of effective vaccines decreased COVID-19 infections, hospitalization, and mortality similarly for all Veterans, including Veterans with low income, homeless Veterans, immunocompromised, the elderly, minorities, and rural Veterans thus reducing health inequalities.

7.
Preprint in English | bioRxiv | ID: ppbiorxiv-427092

ABSTRACT

OBJECTIVEWe explored longitudinal trends in sociodemographic characteristics, reported symptoms, laboratory findings, pharmacological and non-pharmacological treatment, comorbidities, and 30-day in-hospital mortality among hospitalized patients with coronavirus disease 2019 (COVID-19). METHODSThis retrospective cohort study included 43,267 patients diagnosed with COVID-19 in the Veterans Health Administration between 03/01/20 and 08/31/20 and followed until 09/30/20. We focused our analysis on patients that were subsequently hospitalized, and categorized them into groups based on the month of hospitalization. We summarized our findings through descriptive statistics. We used a nonparametric rank-sum test for trend to examine any differences in the distribution of our study variables across the six months. RESULTSDuring our study period, 8,240 patients were hospitalized, and 1,081 (13.1%) died within 30 days of admission. Hospitalizations increased over time, but the proportion of patients that died consistently declined from March (N=221/890, 24.8%) to August (N=111/1,396, 8.0%). Patients hospitalized in March compared to August were younger on average, mostly black, and symptomatic. They also had a higher frequency of baseline comorbidities, including hypertension and diabetes, and were more likely to present with abnormal laboratory findings including low lymphocyte counts and elevated creatinine. Lastly, receipt of mechanical ventilation and Hydroxychloroquine declined from March to August, while treatment with Dexamethasone and Remdesivir increased. CONCLUSIONWe found evidence of declining COVID-19 severity and fatality over time within a national health care system.

8.
Health Aff (Millwood) ; 23(3): 194-200, 2004.
Article in English | MEDLINE | ID: mdl-15160817

ABSTRACT

Place of death is one indicator of the state of end-of-life care. We examine trends in national death certificate data on place of death from 1980 to 1998. During these years the percentage of Americans dying as hospital inpatients decreased from approximately 54 percent to 41 percent. About 310,000 fewer people died in the hospital in 1998 than if the proportion of inpatient deaths had not changed since 1980. For certain diseases the change was much greater. In 1980 whites and African Americans died in the hospital in equal proportions, but in 1998 whites died as inpatients less often than African Americans. These racial differences and their implications deserve further study.


Subject(s)
Black or African American , Mortality/trends , White People , Aged , Aged, 80 and over , Female , Hospitalization/trends , Humans , Male , Middle Aged , Nursing Homes , Terminal Care , United States
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