What Is the Social Vulnerability Index, How Does it Measure SDOH?

June 03, 2021 - By now, most of healthcare is on the same page about the social determinants of health. These factors related to where patients work, live, and play can have a profound impact on their ability to achieve wellness. And in its pursuit of measuring SDOH risk, healthcare has turned to the social vulnerability index (SVI) to meet this moment.

The Centers for Disease Control & Prevention (CDC) and its subagency, the Agency for Toxic Substances and Disease Registry (ATSDR), developed the SVI around 2011 as a means to determine how to allocate resources. The more vulnerable an area, the more likely it will need resources during a crisis.

“Every community must prepare for and respond to hazardous events, whether a natural disaster like a tornado or disease outbreak, or a human-made event such as a harmful chemical spill,” ATSDR and CDC explained in a fact sheet on their website. “A number of factors, including poverty, lack of access to transportation, and crowded housing may weaken a community’s ability to prevent human suffering and financial loss in a disaster. These factors are known as social vulnerability.”

Since ATSDR/CDC developed the social vulnerability index for emergency preparedness, the medical industry has adopted it into its own risk stratification and care management efforts. SVI can help organizations determine which counties they serve might need more SDOH and social services referrals or track other risk factors.

Below, PatientEngagementHIT will outline the social vulnerability index and how it measures SDOH risk.

What Is Social Vulnerability?

READ MORE: Top Social Determinants of Health Barring Patient Care Access

Social vulnerability measures the likelihood a given population or community will need certain resources following an adverse community event, like the natural disasters and public health crises. Social vulnerability can also refer to access to certain social resources including capital (average area income), natural resources like clean water and clean air, or social resources like high-quality educational opportunities.

These factors link directly to the social determinants of health. Environment and air quality, for example, are emerging social determinants of health that can seriously affect an individual’s disease progression. Living in an area with poor air quality could lead to asthma, for instance.

“Socially vulnerable populations are especially at risk during public health emergencies because of factors like socioeconomic status, household composition, minority status, or housing type and transportation,” ATSDR/CDC write.

How ATSDR/CDC Calculates SVI

ATSDR/CDC uses United States Census information to calculate the SVI on four key themes comprised of a total of 15 social factors, the organizations say. Those four themes include socioeconomic status, household composition and disability, race/ethnicity and language, and housing or transportation status.

Those 15 social factors are grouped within those themes as follows:

• Socioeconomic status: below poverty, unemployed, income, no high school diploma
• Household composition and disability: persons over age 65, persons under age 17, persons over age 5 with a disability, single-parent households
• Race/ethnicity and language: minority status, ability to speak English “less than well”
• Housing or transportation status: multi-unit structures, mobile homes, crowding, no vehicle ownership, group living quarters

READ MORE: How Do Social Determinants of Health Affect Patient Wellness?

Again, these themes link directly to some of the top common social determinants of health currently prioritized by healthcare professionals.

ATSDR/CDC uses the US Census data to rank census tracts for each of those individual themes, as well as giving each census tract an overall social vulnerability score. The higher the SVI, the more social vulnerability in that area, meaning that area may need more resources to thrive.

How Can Healthcare Use SVI?

ATSDR/CDC clearly state they designed SVI for emergency and public health preparedness, the groups write online. Government agencies and other support groups can use SVI data to allocate resources, create emergency response plans, determine how personnel will assist people in crisis, and flag communities that might need additional resources even after a disaster strikes.

However, as healthcare has increasingly recognized the importance of social determinants of health, some organizations have adopted the SVI as part of its risk stratification plans. Because many of the social factors considered as part of the SVI score link directly to SDOH, organizations can plan which neighborhoods or counties will need certain types of social resources to thrive.

At CommonSpirit Health, layering maps of high disease incidence over the SVI data maps provided critical insights for Alisahah Cole, MD, system vice president of population health.

“If you look at rate of diabetes, if you look at rate of heart disease, obesity, if you look at unnecessary ED utilization, if you look at readmissions—guess what?” Cole said during a keynote address at Xtelligent Healthcare Media’s Virtual Patient Experience Summit.

“You're likely going to see a correlation between having higher incidents or rates of those medical conditions or those utilization patterns in communities that have high social vulnerability index scores.”

In other words, higher social vulnerability isn’t just linked to challenges during a natural disaster and public health emergencies; it is linked to key barriers blocking overall patient wellness. According to Cole, it is essential to address those social vulnerabilities so every patient has a chance to obtain optimal health.

As the medical industry continues to consider social determinants of health as a core component of their patient care management strategies, they may also consider incorporation SVI data in their risk stratification plans. In doing so, organizations can determine key community health partnerships, streamline SDOH data collection, and better track patient social and healthcare needs.