This Little-Used Hack Could Be a Game-Changer for Health Disparities

Doctors can prescribe medicine for health conditions. What can they do for homelessness, food insecurity, and other social determinants of health?

As a bright-eyed family medicine physician fresh out of her residency, Laura Gottlieb expected to face challenges as she cared for low-income Seattle residents. She steeled herself to confront the ravages of addiction and HIV. Gottlieb knew many had histories of abuse and trauma, and they also had to manage chronic conditions such as asthma, cardiovascular disease, and kidney failure.

Gottlieb had tools, however imperfect, to address her patients’ direct and immediate medical needs. She could prescribe insulin for diabetes, inhalers for asthma, and statins for high cholesterol. What she couldn’t do was ensure that the people she treated had a safe place to live, enough food to eat, and reliable transportation. As time passed, Gottlieb came to understand that it was these factors — what scientists call social determinants of health, or SDoH — that were playing the largest role in her patients’ health, not anything she did or didn’t do.

Gottlieb couldn’t prescribe a visit to the food pantry nor could she assist with finding Section 8 housing or rent assistance. Lots of physicians were finding themselves in Gottlieb’s shoes, but no one had any way to figure out just how many patients had unmet social needs that were affecting their health — a key step in developing programs to meet those needs. Although many physicians like Gottlieb tried to provide that assistance as part of what they felt was their sacred duty, if they didn’t have any way to bill for these services rendered, it would be impractical to provide them to large numbers of people over long periods of time.

Now a health policy scientist at the University of California, San Francisco, Gottlieb has become an advocate for a little-used set of diagnostic codes that could help address some of the deepest disparities in medicine. The codes, nicknamed Z-codes due to the letter assigned to them in the 10th edition of the International Statistical Classification of Diseases (ICD-10), allow physicians to document the social factors in their patients’ lives that are contributing to their health. Z-codes can be used to detail everything from difficulty affording nutritious foods (Z59.4) to absence of a family member due to military deployment (Z63.31).

What makes using Z-codes such a brilliant hack is how they can provide a universal shorthand to summarize complex social issues and provide a ready way for social services and the medical industry to communicate with each other.

“These codes create a common medical vocabulary that is really, really important for things that health care systems are now starting to do around identifying and addressing social conditions as a strategy for improving health,” Gottlieb said.

By itself, a Z-code simply provides information — hardly enough to address the vast health disparities that exist in the United States and elsewhere. What makes using Z-codes such a brilliant hack, Gottlieb explains, is how they can provide a universal shorthand to summarize complex social issues and provide a ready way for social services and the medical industry to communicate with each other. If someone is diagnosed with homelessness or food insecurity, that could open the doors to greater access to housing, SNAP benefits, and other supports. Studies show that addressing these conditions not only alleviates immediate suffering, it can also improve overall health. And policymakers can use information about how many people in a given area have Z-code diagnoses as a way to target larger, more structural efforts geared toward tackling these issues.

Although the usage of Z-codes isn’t without limitations and critics, health disparities experts say they could prove to be society’s best option for taking action on these deeply rooted issues.

“We need a way to systematically identify and provide proactive care,” says Alex Krist, chair of the U.S. Preventive Services Task Force. “These social determinants have a bigger impact on health than nearly anything else.”

In the 1990s and 2000s, studies began to accumulate indicating that not only were social circumstances and physical health inextricably linked, the former was the strongest driver of the latter, more important than genes and even behaviors like diet and exercise. For decades, the ICD has tried to provide a comprehensive compendium of the factors impacting health, including a section devoted to “factors that influence health status and contact with health services.” But it wasn’t until a 2015 revision to the ICD-10 clinical diagnosis codes that formal codes to diagnose the range of social and environmental factors that impact health first appeared.

By the mid-2010s, SDoH had become one of medicine’s top buzzwords, with nearly every conference and physician gathering having at least one session devoted to the topic, says Rachel Gold, lead researcher at the Oregon Community Health Information Network. The issue had become so pressing that in 2016, the Centers for Medicare and Medicaid Services (CMS) officially added Z-codes to their Medicare fee-for-service claims, she said.

“Nothing happens in the health care sector unless there’s a code for it, unless you can document it.”

For the medical industry, the ICD-10 is more than just a compendium of diagnoses for patients. The listing of alphanumeric codes documents the precise nature of a person’s medical issues (including everything from T87.43, infection of amputation stump, right lower extremity; to Y93.D1, injury resulting from knitting and crocheting) both for their medical record and for billing purposes. This latter use is what drives most of the ICD-10 code usage among physicians, explains Gottlieb.

“Nothing happens in the health care sector unless there’s a code for it, unless you can document it,” Gottlieb said.

Due to the scattershot nature of American health care, which is spread over a panoply of providers, payers, and facilities, many of which use different systems to document patient needs, obtaining a comprehensive view of SDoH was nearly impossible. So another enormous potential benefit of coding for SDoH is creating a streamlined, standardized, extensive set of research-ready patient data.

Carly Hood-Ronick, social determinants of health manager at the Oregon Primary Care Association, says, “Right now we collect a lot of medical information about patients, and we’re able to look at the burden of disease, but we don’t have a lot of information on education level or income or neighborhood and that kind of thing needs to be standardizing also.”

“We use standard coding for diseases so that we can study their epidemiology. We need to do the same for social needs, otherwise it’s like the Tower of Babel.”

ICD-10 Z-codes provided a ready solution, since anyone remotely involved in the health care system was familiar with the document itself. It also gave physicians and researchers a standardized vocabulary to use when describing SDoH.

“We use standard coding for diseases so that we can study their epidemiology. We need to do the same for social needs, otherwise it’s like the Tower of Babel,” Gold said.

Integrating these questions into a primary care visit might seem straightforward, but when you also account for the vast number of screenings and procedures that must take place in a visit that can last just several minutes, it’s not surprising that doctors struggle, Gold says. And if doctors don’t have ready access to community resources that can provide these services to their patients, many won’t bother asking.

A September 2019 paper in JAMA Network Open by Gold, Gottlieb, and colleagues showed just how challenging this integration can be. Of the 2,190 physician practices and 739 hospitals the researchers queried, only 24% of hospitals and 16% of physician practices asked their patients about social needs. A January 2020 report from CMS about the first year of Z-code usage in their billing codes was even more grim: Only 1.4% of Medicare’s 33.7 million fee-for-service members had Z-code diagnoses in their charts. Nearly three-quarters of those with Z-codes had hypertension, and 53% had major depression, the report showed.

Whatever the reason for low Z-code usage, it isn’t that patients don’t want to be asked. When California’s Kaiser Permanente asked its members about the issue, it found unmet social needs to be a major concern among its members, even those in the highest income brackets. Four in 10 said they regularly worried about meeting their family’s food needs, and 35% worried about housing. Over 90% of respondents said they thought their doctor should ask about food security, and 83% wanted to be asked about stable housing. The issue, then, according to what Gold found in her JAMA study, was that many hospitals reported a lack of time and financial ability to ask social needs questions.

It’s a problem Jacob Reider was faced with when he took the helm of Alliance for Better Health in 2016. At the time, the network of community health organizations was midway through a new program to improve health and reduce Medicaid spending on New York’s neediest patients. Alliance saw that many of those on Medicaid and without health insurance overwhelmingly relied on hospital emergency rooms for basic medical care. Not only was it expensive, it also left these Albany-area residents — overwhelmingly low-income minorities — markedly less healthy. So Alliance developed a plan to focus on improving health while preventing unnecessary ER visits.

There was only one minor problem: Reider found it didn’t work. The issue was straightforward.

“The problem isn’t at the hospital. The problem is upstream of the hospital,” Reider said.

Adding Z-codes to medical records might document a patient’s needs, but that didn’t connect them with the required services for their diagnoses. Reider wanted to streamline that process by organizing local nonprofits that addressed community needs such as food, shelter, and transportation into a single network called an Independent Practice Association (IPA). In medicine, most IPAs are groups of independent physicians who band together to negotiate contracts with insurance companies and other businesses, but Reider realized that community-based organizations offering social services could form an IPA to contract services with Medicaid health plans called Managed Care Organizations (MCOs), and the nonprofits would be able to one day see shared savings. Physicians would be able to screen their patients for social needs and then refer them to a local food pantry or housing organization, just like they would provide referrals to medical specialists. The Z-code diagnoses would also allow researchers to aggregate the data and identify whole communities that could benefit from help. It was a way of reducing health care costs by addressing these issues before they interfere with health.

The Gravity Project, launched in 2018 with funding from the Robert Wood Johnson Foundation, is gathering information from eight sites nationwide to obtain large datasets on SDoH using Z-codes to enable researchers to get a broader view of what the needs are and how they intersect with the health care system.

“The health plans are starting to get it. If they spend $3 upstream, they’ll save $6 downstream,” Reider said.

Is all this too good to be true? To Arrianna Planey, a social scientist at the University of North Carolina, Chapel Hill, the issue isn’t that doctors are connecting patients to community resources. It’s that Z-codes are, by their nature, individual assessments, and these solutions, however well intentioned and seemingly revolutionary, are geared toward finding individual answers. Fixing systemic problems like racism, affordable housing, and not enough food needs more than a single person’s diagnosis with homelessness. As long as the U.S. continues to eschew investment in social services, the country will continue to pay more in health care no matter how useful Z-codes prove to be.

“You’re just putting a Band-Aid on the problem,” Planey said. “It’s too little, too late.”

Karina Davidson, senior vice president of research at New York’s Northwell Health, says that even if frontline physicians take on the responsibility to help fix some of these social problems, they don’t have the authority to make the kinds of broad-scale policy changes that will make a lasting difference, such as expanding Medicaid or lowering thresholds to qualify for housing and food assistance.

“And responsibility without authority is a recipe for disaster,” Davidson said.

Although Gold and Gottlieb agree that drivers of SDoH are more complex than any Z-code can address, they say that the codes themselves provide a unique and useful starting point for the medical community to begin to assess the social needs of the communities they serve.

“When we have the power of data, when I can say that these patients who don’t have access to food in my neighborhood are more likely to have uncontrolled diabetes, I can then act as an advocate at the policy level or the community level and say we need more resources here. And that makes me a more powerful advocate,” Gottlieb says.

Just your friendly neighborhood public health reporter, covering the intersection of health and environment. Lover of coffee, knitting, cycling, and cats.

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