In this study, we present a novel use of the Admissions Discharge Transfer feed to evaluate potential biases in single-institution screening for the high-need population for a program that aims to enroll patients with a recent history of high healthcare utilization. Our results show that VUMC’s EHR data from the primary hospital shows high sensitivity in identifying high-need patients. Furthermore, we did not observe any statistically relevant differences in sensitivity across race or insurance status. For this specific institution, this is reassuring that selection criteria to date does not have bias. This study demonstrates the value of using state-wide ADT data streams to better characterize a health systems population and determine whether screening biases may exist that could further exacerbate existing inequities in care delivery. Future studies can evaluate all-payer claims databases to reliably show the true prevalence of the high-need population.
To our knowledge, there are no known studies on bias in selection criteria for the high-need population. Kilaru et al. used the Dartmouth’s Hospital Referral Regions (HRR)s and Hospital Service Areas (HSA)s to examine admission patterns, and noted that fewer than half the patients were admitted in the HSAs of residence however, patients living in populous urban HSAs with multiple large and teaching hospitals, tended to remain in same HSAs for inpatient care(13). However, within the same HSAs, studies of patients moving from one hospital to another, or known colloquially as doctor shopping is limited to patients with substance use disorder(14). Our results would support the findings that “doctor shopping” is a rare phenomenon. Only recently, all payer claim databases which give a more comprehensive view of populations have become available, however they are challenges with timeliness in the availability of this data(15), which in the high-need population is essential for real time enrollment into programs.
Our study was reassuring that the current screening using VUMC’s electronic medical records show high sensitivity in recognizing the high-need population regardless of race or insurance status. Bias occurs when an algorithm systematically favors one outcome over another (16), and there had been concerns in previous studies of how algorithms were trained to distribute resources on basis of predicted health costs have prioritized healthier White patients over sicker Black patients because of reduced access to care and tend to use fewer health services (17). Algorithmic and Clinical Decision Support fairness prevents discrimination involving protected groups which are defined such as race, gender, religion, physiologic variability, pre-existing conditions, physical ability, and sexual orientation. Although there is increased focus on bias evaluation using checklists such as the Prediction Model Risk of Bias Assessment Tool (PROBAST)(18), there is still a lack of agreed standard in evaluating clinical decision support tools and prediction models for thorough analysis of fairness.
Health systems evaluating programs targeting their high-need population, would need to be cautious in the assumption that their EHR is of equal sensitivity as VUMC’s screening for this population, as every health system and every region’s referral patterns are different. University of Chicago’s Comprehensive Care Program(19), and Mount Sinai’s PACT (3)programs are both in the top metropolitan statistical areas as compared to Nashville.(20) Additionally, in the Nashville metropolitan area in 2020, VUMC’s Emergency Room was the busiest in the Nashville metropolitan areas with 79,975 ED(21) encounters compared to the next busiest local hospital with 42,488 encounters(22). Additionally, the medical center serves as a referral center for the region and beyond, with 14.9% of hospital discharges in 2020 from outside Tennessee, and 41% of discharges outside the counties surrounding the medical center(21). These admission characteristics are likely to differ across other regions in the country.
It must be pointed out that the lack of racial or insurance differences in sensitivity in the current screening may mask existing structural inequalities in the care for high-need patients, as there is no systematic study of the actual prevalence of the high-need population, and the population’s referral patterns within Tennessee. Additionally, there are no studies understanding disparities in access to care for this population which may affect identification of the population - as our criterion of high-need is dependent on utilization. Tennessee has the second highest rate of hospital closures in the United States, with 13/16 closures since 2010 in the rural areas(23), and may explain why 55.9% of VUMC’s discharges are not from the Nashville metropolitan area (21). However, it is unclear how these closures affect access to care of the high-need population, and how many patients are not able to get to VUMC because of its distance especially those living in the rural counties in Tennessee.
The results of the study were reassuring that we were did not appear to be inadvertently perpetuating disparities through our screening algorithms for program eligibility, as we strove to use a health equity lens (24, 25) in the implementation of our program. The VICP program currently manually screens the electronic medical record, as there were concerns to ensure fairness in screening prior to automating through a clinical decision support system. There are no studies on clinical decision support in screening for the high-need population as previously there is disagreement on its definition of high-need (26) only recently has Medicare given definition to the population using a combination of HCC scores and unplanned admissions in the last year (27), and the program recently updated our criteria. Despite the positive results, we intend to still incorporate the ADT feed into our screening as referral patterns are not static and can change especially with hospital acquisitions and closures.
Limitations
Researchers were given data on high-need patients, that have a relationship with VUMC either through a hospital or ED visit. We are unable to see the total population of “high-need” within middle Tennessee (including those from other healthcare systems) because of this limitation. Additionally, as we had limited our data set from both sources to patients who are defined as high-need, we are not able to calculate specificity and negative predictive value of our current VIC VUMC EHR Criteria. Lastly, the VICP criteria for the current study does not match Medicare’s definition of high-need that combines admissions and HCC score data. Future research should examine for potential screening biases with these newly adopted criteria.