By Deborah Borfitz
September 13, 2021 | A street medicine program is employing point-of-care testing (POCT) to mitigate the heightened risk of chronic diseases and death among the homeless in Los Angeles, according to Allison Chambliss, Ph.D., director of clinical chemistry at the University of Southern California’s (USC) Keck School of Medicine, speaking at the recent Next Generation Dx Summit. Testing for glucose, hemoglobin, and hemoglobin A1c are currently available, but the menu will expand to include urine-based assays, she says.
The state is in a “homeless crisis,” Chambliss shares, and accounts for half of all unsheltered people in the Unites States. In Los Angeles, many of the newly displaced live in a 50-block area downtown known as Skid Row where 10,000 people rotate between living in shelters, in hotels, and on the street with a variety of physical and mental conditions.
The mortality rate of the unsheltered is three times greater than the sheltered homeless and 10 times greater than the general population, she says. They also have more chronic diseases and emergency department visits, and their 30-day hospital readmission rate and lengths of the stay are considerably longer.
POCT is intended to remove barriers to basic medical care for the homeless without any of the usual advantages of delivering those tests inside the hospital, including a controlled environment with connectivity, processes that overlap with other clinical operations, and pathology and POCT staff available for support, Chambliss says.
Any POCT done outside the hospital requires a CLIA (Clinical Laboratory Improvement Amendments) certificate and, in California at least, state registration, she continues. The CLIA certificate applies to tests approved by the Food and Drug Administration or waived through the agency’s Emergency Use Authorization process. As some facilities learned from cease-and-desist letters from the Centers for Medicare & Medicaid Services (CMS) last fall, the need for proper CLIA certification extends to community-based COVID-19 testing.
Unlike other out-of-hospital settings, street medicine requires a “go to the people” approach that happens on foot or, alternatively, by bike, horseback, or kayak, explains Chambliss. The founder and director of the program at USC is Brett Feldman, a physician assistant.
Poised For Expansion
The homeless are identified for street-based care when they present in the emergency department at USC Medical Center, Chambliss says. The street medicine program is now formally a division of the medical school’s family medicine department and is credited with a 10% drop in the hospital readmission rate.
To realize and maintain success means rendering full-service care that is “as close as possible” to in-clinic care, she says, in terms of physical exams and physician-patient dialogue. Labs are needed for monitoring blood glucose levels, given the high prevalence of diabetes among people living in the street, as well as creatinine and potassium levels, as many homeless people are on various therapeutics for heart failure.
Rapid results allow for immediate intervention and dispensing of needed medications, she adds. The thought of doing blood draws on the street was abandoned because of sample stability concerns, the fact that results wouldn’t be available in real time (running the risk that individuals would change their mind about seeking medical care), and anticipated difficulties in patient follow-up.
The street medicine team initially presented a POCT “wish list” to the lab team, which included items such as a urine test for pregnancy and whole blood creatinine and electrolyte tests, says Chambliss. They subsequently settled on the important considerations: small and easy to carry, durable and wireless, room temperature reagent stability, methods correlate well with hospital lab methods, and testing personnel are familiar with the devices from hospital use.
A lot of discussion ensued about regulatory considerations. Although CMS allows a mobile lab to operate under the certification of a main lab site, Chambliss says, the lab director felt the street medicine program had the wherewithal to secure its own CLIA certificate.
Test results are being reported in patients’ medical chart, albeit retrospectively, since many of the homeless being served by the street medicine program are already in the system by virtue of a previous visit to the emergency room and the same POCT devices used on the street are used at the hospital, she says. Testing personnel include physicians, physician assistants, and nurses (including one who oversees compliance).
A newly launched family medicine residency program at the Keck School of Medicine incudes a rotation through the street service, Chambliss notes.
Not all tests can be done on the street, but the program additions Chambliss hopes to see soon are venipuncture; transportation back to the hospital; an equipment van with centrifuge, on-site label printing, and refrigeration unit; and development of a critical value notification policy to define the potentially life-threatening test results requiring a prompt and appropriate care response from providers.
Plans call for expanding the patient population as the physician base grows as well as enlarging the POCT menu to include urine testing, she concludes.