Accuracy of the Veterans Health Administration COVID-19 (VACO) Index for predicting short-term mortality among 1,307 Yale New Haven Hospital inpatients and 427,224 Medicare patients

Abstract

BackgroundThe Veterans Health Administration COVID-19 (VACO) Index incorporates age, sex, and pre-existing comorbidity diagnoses readily available in the electronic health record (EHR) to predict 30-day all-cause mortality in both inpatients and outpatients infected with SARS-CoV-2. We examined the performance of the Index using data from Yale New Haven Hospital (YNHH) and national Medicare data overall, over time, and within important patient subgroups.Methods and findingsWith measures and weights previously derived and validated in a national Veterans Healthcare Administration (VA) sample, we evaluated the accuracy of the VACO Index for estimating inpatient (YNHH) and both inpatient and outpatient mortality (Medicare) using area under the receiver operating characteristic curve (AUC) and comparisons of predicted versus observed mortality by decile (calibration plots). The VACO Index demonstrated similar discrimination and calibration in both settings, over time, and among important patient subgroups including women, Blacks, Hispanics, Asians, and Native Americans. In sensitivity analyses, we allowed component variables to be re-weighted in the validation datasets and found that weights were largely consistent with those determined in VA data. Supplementing the VACO Index with body mass index and race/ethnicity had no effect on discrimination.ConclusionAmong COVID-19 positive individuals, the VACO Index accurately estimates risk of short-term mortality among a wide variety of patients. While it modestly over-estimates risk in recent intervals, the Index consistently identifies those at greatest relative risk. The VACO Index could identify individuals who should continue practicing social distancing, help determine who should be prioritized for vaccination, and among outpatients who test positive for SARS-CoV-2, indicate who should receive greater clinical attention or monoclonal antibodies.

Early initiation of prophylactic anticoagulation for prevention of coronavirus disease 2019 mortality in patients admitted to hospital in the United States: cohort study

“…69 In separate analyses, we developed a predictive index based on Veterans Affairs data 70 and have since shown that the risk of covid-19 mortality associated with age, sex, and comorbid disease diagnoses that we observed in Veterans Affairs data was consistent across other academic and national healthcare samples in the US. 71 Our key finding in the current analysis has also been shown in smaller, non-veteran healthcare systems 13 14 ; thus, effects reported in this study are probably generalizable to the wider US population. Fifth, although individuals in Veterans Affairs care represent a diversity of backgrounds, women represented a small proportion of the sample population and thus results might not be generalizable to women.…”

“…However, previous research has established that after adjusting for age, sex, race, ethnicity, region, and residence type, all of which were accounted for in this study, total disease burden between veterans and non-veterans does not differ 69. In separate analyses, we developed a predictive index based on Veterans Affairs data70 and have since shown that the risk of covid-19 mortality associated with age, sex, and comorbid disease diagnoses that we observed in Veterans Affairs data was consistent across other academic and national healthcare samples in the US 71. Our key finding in the current analysis has also been shown in smaller, non-veteran healthcare systems1314; thus, effects reported in this study are probably generalizable to the wider US population.…”

COVID-19 in Veterans: A Narrative Review

“… 43 The VACO index can help clinicians make better treatment decisions for veterans with COVID-19, such as determining who should be managed as inpatients who require close clinical follow-up, and even determining who is a priority for COVID-19 vaccination. 44 …”

Development of COVID-19 Severity Assessment Score in Adults Presenting With COVID-19 to the Emergency Department

“…Furthermore, the utility of this score in COVID-19 is not well established. Other scores developed include the VACO Index [4], 4C mortality score 5] and COVID-GRAM [6]. Additionally, scores previously used for non-Covid pneumonia such as CURB-65 have also been tested on COVID-19 patients [7].…”

“…However, they often suffer from certain de ciencies, limiting their generalized applicability. For example the VACO index, an otherwise thoroughly investigated and validated score, has signi cantly different Area under the Curves for different subgroups, implying limited generalizability of the score in various populations [4]. Another score, the COVID-GRAM, has good predictive ability in low-risk patients for progression to severe disease, but overestimates risk in high-risk patients [6].…”