The HIV care continuum has become the main tool for measuring medical care outcomes for people living with HIV -- from diagnosis to retention in care and, ultimately, to viral suppression. Since the advent of the HIV care continuum, the portion of people living with HIV who are engaged in care has been used as a basic proxy for the health care system's ability to keep individuals and populations healthy.
According to the Centers for Disease Control & Prevention (CDC), young people aged 13-24 who are living with HIV are less likely to be linked to care than HIV-positive people of all other age groups, and Latinx and blacks of any age are less likely to be linked to care than whites.
For public health experts, categorizing groups of people who are at risk of falling out of the care continuum is only part of the issue. Little research explains why some people are maintained in care while others are not. However, new data presented at IDWeek 2017 shed light on this question and offer new insights that might help end disparities in the HIV care continuum.
Specifically, two study abstracts presented by Jessica Ridgway, M.D., assistant professor, Section of Infectious Diseases and Global Health, University of Chicago Medicine, looked at patient and provider issues that impact retention in care.
Ridgway's research studies, both conducted in Chicago, asked whether crime levels and/or the distance to a health care facility matter for patients' ability to keep medical appointments, as well as how electronic data sharing could streamline clinicians' efforts to locate patients who have fallen out of care.
Travel Time and Crime Rates
People who live below the poverty line are more at risk for HIV and have worse health outcomes overall. But why? By examining retention data from Chicago's South Side, Ridgway and her colleagues explored two possible factors: crime rate and distance to a clinic.
"People don't live their lives in a vacuum," said Ridgway. "Besides people's individual factors that influence retention, their neighborhood and community context can also impact their health along the HIV care continuum. For example, if clients live in a high-crime area or have poor access to transportation, they might find it unsafe or difficult to come to clinic."
"We aimed to determine whether crime rate, travel time, or travel distance to clinic were associated with retention in care ... among people living with HIV at the largest provider of HIV care on the South Side of Chicago," Ridgway said.
To answer this question, they queried publicly available data from the Chicago Open Data Portal, measuring travel time to an HIV clinic, both by car and by public transportation, and then matching that transport route to crime rates within a two-block radius. Then, they sorted patients into three categories: continuously retained, intermittently retained, or lost to follow up.
Of the 780 patients included in the analysis, 35% were continuously retained, 50% were intermittently retained, and 15% were lost. However, the reasons cited for lack of retention were mixed.
"Interestingly, we did not find an association between neighborhood crime rate and retention," Ridgway said. Instead, the biggest factor associated with retention was distance to the clinic. Patients who were continuously engaged in care lived an average of 3.6 miles from a clinic, while those intermittently engaged and lost to follow up lived an average of 3.9 miles away.
In addition, the average travel time was longer for those who were intermittently engaged or lost to follow up. By car, travel time averaged 15.9 minutes for those retained in care and 17.1 and 17.5 minutes, respectively, for the other groups. By public transport, average travel time was 37.2 minutes for the continuously engaged group and 42.9 minute for the other two groups.
Ridgway notes that, while the results were not statistically significant (P < .05), there was a trend toward a shorter distance (P = .07) and shorter car travel time (P = 0.06) among continuously engaged versus intermittently engaged.
"This suggests that providers should consider how to ease travel burden for their patients, whether that be through scheduling visits for clients who live far away when traffic is lighter, spacing out visits, or even considering telemedicine," Ridgway said.
Related: Better Use of Electronic Health Records Might Help Close HIV Testing Gap in U.S.
Finding Patients Lost to Follow Up
Although the Affordable Care Act created federal mandates around electronic medical records (EMRs) seven years ago, implementation challenges remain.
When it comes to the HIV care continuum, the myriad of existing EMR systems (for providers, pharmacists, public health systems, etc.) that don't communicate with one another makes it difficult for providers to know whether their patients have stopped seeking care and require additional outreach or have merely switched over to a new clinic.
EMR data is often "not shared due to lack of infrastructure and privacy concerns," said Ridgway. Therefore, "we often do not know whether patients are really lost to follow up or whether they are actually dead or transferred."
Better electronic data sharing could improve the accuracy of retention data and prioritize resources for patients who are no longer engaged in care. To address this issue, Ridgway and her colleagues received funding from the CDC to conduct a project called Data to Care (D2C) within the Chicago health department. Their objective was to analyze how many patients marked as "lost" within an adult HIV clinic at the University of Chicago Medicine were actually retained in care elsewhere in a different medical network.
"As an HIV clinic, we have certain patients who are lost to follow-up," Ridgway said. "However, all clinics are required to report HIV labs to the health department. Therefore, the health department may have more recent information about some of our patients who are lost to follow-up from our clinic. If they received lab reports from other care providers for those patients, then they can assure us that they are in care elsewhere. Then, we know that we do not have to keep trying to contact those patients to re-engage them in care."
Of the 780 patients who received care at Ridgway's clinic over the past five years, only 360 were still retained in care by March 2017. Ridgway's group shared data with the Chicago Department of Public Health for 492 names and were able to find matching data for 294 people by searching alternative spellings, phonetics, and birth dates, as well as by cross-referencing with the CDC's national enhanced HIV-AIDS Reporting System (eHARS) database.
The sharing ultimately improved the accuracy of the clinic's data. Ridgway's team learned that 13.4% of patients previously thought to be lost to follow up had either transferred to another clinic or had died, according to health department data.
"I think the regional health information organizations are going to be really important in the future," said Jason Zucker, M.D., Columbia University Medical Center, who was not involved in the research.
"In large cities, like Chicago and like New York, [there] are multiple providers in a small geographic area, and patients often frequent multiple, different emergency rooms, different health systems, who may not be sharing records," Zucker said.
By applying a model similar to what Ridgway's team did in Chicago, HIV providers can better "understand whether our patients are really in care, just at a different site," added Zucker.