Data Lights the Path Toward Ethical COVID-19 Vaccination Distribution

The following is a guest article by Kurt Waltenbaugh, CEO at Carrot Health.

As millions of healthcare workers begin receiving the first vaccination to protect against COVID-19, public health officials and government leaders continue wrestling with not only the operational challenges of scale—this is the first mass vaccination since smallpox (1958-1977) and polio (1980s-present)—but also the ethics of vaccination priority. The latter comes down to a simple, but ethically complex, question: Is our priority to reduce transmission or protect those most vulnerable to its impact?

The order of inoculation looks very different depending upon how this question is answered. If we are seeking to protect the most vulnerable and reduce deaths, priority would be given to the elderly, those with multiple chronic conditions, the BIPOC community, and those in close quarters such as prisons. If, however, the priority is to reduce transmission so society and the economy can get back to something resembling normal, the initial focus needs to be on those who spread the virus—the healthy and socially active 18-34-year-olds who are most likely to be asymptomatic and those with “essential” jobs who have contact with a wide array of people (e.g., service workers, delivery drivers, teachers, grocery clerks).

There is science to support both approaches. One study, while not yet peer-reviewed, suggests an optimal outcome is achieved by prioritizing people over the age of 60. Others question the wisdom of treating the elderly first, suggesting that the few potential years left for seniors outweigh the economic impact to the young. The World Health Organization (WHO), for example, uses YLL (Years Life Lost) and YLD (Years Living with Disability) to create a DALY (disability-adjusted life year), which is a measurement of the temporal impact of a disease. A study in Italy that looked at data through April 2020 suggests that permanent impacts like disability or death outweigh temporary financial impacts such as job loss by 300%—an impact that continues to climb in tandem with the pandemic’s death rate.

The answer lies somewhere in the middle, with an approach that balances the need to both reduce deaths and transmission as quickly as possible. To get there, we need to listen to the data.

The Interim Playbook

Safe, effective immunization is a critical component in reducing COVID-19-related illnesses, hospitalizations and deaths. According to the COVID-19 Vaccination Program Interim Playbook for Jurisdiction Operations from the Centers for Disease Control and Prevention, the ultimate goal is to have enough supply available for all who wish to be vaccinated. Until then, however, initial distribution efforts will focus on first responders and those at highest risk for contracting and developing a severe illness from COVID-19.

The CDC’s interim playbook for public health programs and partners provides guidance on how to plan and operationalize a vaccination response to COVID-19, outlining three distribution phases:

  1. Limited COVID-19 vaccine doses available
  2. Large number of doses available
  3. Sufficient supply of vaccine doses for entire population (surplus of doses)

The goal of Phase 1 is to concentrate distribution efforts on reaching the initial populations of focus. These “critical populations” are defined as meeting one or more of the following criteria:

  • Critical infrastructure workforce: Healthcare personnel and other essential workers
  • People at increased risk for severe COVID-19 illness: Long-term care facility residents, people with underlying medical conditions, people 65 years of age and older
  • People at increased risk of acquiring or transmitting COVID-19: Racial and ethnic minority groups, tribal communities, homeless populations, and similar
  • People with limited access to routine vaccination services: Rural community dwellers, people with disabilities, under- or uninsured groups, and similar

The U.S. government and healthcare agencies need a clear mechanism to accurately define, identify, and estimate critical populations at national, regional, and local levels. That framework has been developed by our team using Carrot Health data and models.

A Framework for Prioritization

Since the declaration of the pandemic in March, Carrot Health has invested significant research, data analysis, and predictive modeling resources toward developing a strong understanding of COVID-19 impacts. This includes identifying vulnerable populations, the social and economic well-being of different communities, and potential long-term effects.

Two models in particular are relevant to assessing COVID-19 risk:

  • Carrot Health Social Risk Grouper® (SRG): The SRG is a proprietary social determinants of health (SDoH) taxonomy that helps the healthcare industry understand, identify, measure, and quantify the social barriers and circumstances in which people live. It helps predict the likelihood of an individual having an adverse health outcome due to SDoH and scores every individual in the U.S. with a range of 0 (no risk) to 99 (highest risk).
  • COVID-19 Critical Infection Risk Index: Using factors demonstrated to influence the severity of COVID-19 infection (e.g., smoking status, age, underlying medical conditions), risk factor statuses were predicted at an individual consumer level to match the proportion of individuals estimated to have each risk factor by age and gender. This was then used to create a simulated dataset to estimate weights for the Index, which then scored at the individual consumer level. The top 10% of the calculated index nationwide were labeled as those most likely to be at risk of a “critical case” requiring an intensive care unit level of care/ventilator.

These two models were used to score every individual consumer in the U.S. to assess the likelihood they meet the definition of a critical population. These scores can be aggregated at a census tract, ZIP Code, or county level to help direct vaccine distribution prioritization in Phase 1.

Every county in the U.S. can be stratified into a critical population risk tier (Figure 1). For example, we identified 18 million people in 328 counties who fall into Tier 1, the highest risk. This tier includes those who scored highest on both the SRG and COVID-19 Critical Infection Risk Index. The second largest population—96 million people in 1,101 counties who are also deemed as higher risk index-higher score—falls into Tier 2. Tier 3 encompasses 1,836 counties and 74 million people, and Tier 4 includes 1,098 counties and 144 million people.

Figure 1: Critical Population Risk Tier by County

Source: Carrot Health

Every adult nationwide was also scored and mapped at the county level (Figure 2). Interestingly, no state is without at least one county in at least the Tier 1 or 2 category and some are hit relatively worse than others.

Figure 2: COVID-19 Vaccination Distribution Critical Population Index in U.S. by County

Source: Carrot Health

The Ethics of Distribution

Among the challenge identified in the initial phase of vaccine distribution, we also need to consider the ethics of distribution. Again, it comes down to the question of which populations to prioritize, those at the highest risk of developing a severe COVID-related illness or those at the highest risk of spreading the virus?

Equipping public health agencies and their partners with the appropriate insights and granularity of data can help guide them through this medical ethics dilemma. There is no one-size-fits all approach that works for every community. Rather, the data can guide and inform the emphasis placed on severity vs. transmission.

Based on our data analytics and insights, we propose an appropriate balance of the following dimensions for each targeted community:

  • Target populations at highest risk of spreading the virus
  • Target populations at highest risk for COVID-related mortality and morbidity
  • Educate populations identified as less likely to comply with vaccination

With multiple vaccines now available, we are finally seeing some light at the end of the COVID-19 tunnel. And while the vaccine supply may be initially limited, decisions about who gets those first doses could save tens of thousands of lives. With so much at stake, leveraging the right data to inform these life-and-death decisions will help speed the end of the pandemic.

About Kurt Waltenbaugh

Kurt Waltenbaugh, Founder and CEO of Carrot Health, is a serial entrepreneur who has built successful analytic solutions, products and companies in the healthcare, retail, manufacturing, education/credentialing and fundraising industries. His previous companies were sold to Oracle and Pearson Education. Most recently, he was responsible for Product Strategy at Optum, Inc. (UnitedHealth), building data analytic businesses for the Provider, Payer and Employer markets.