At U.S. clinics advertising unproven stem cell treatments, roughly two-thirds of the clinicians may be physicians, but a new study suggests these doctors are often trained in specialties unrelated to the services they provide.

“About half of the companies we examined offer unproven stem cell treatments for conditions (for) which they do not have a physician with the appropriate residency and fellowship training,” said senior study author Zubin Master, of the Biomedical Ethics Research Program at the Mayo Clinic in Rochester, Minnesota.

“As regenerative medicine advances and potential therapies become available, it is important for patients to be treated by clinicians who are appropriately qualified to provide such care,” Master said by email.

More than 700 U.S. clinics advertise unproven stem cell treatments, Master and colleagues note in JAMA.

All too often, these treatments involve approaches that aren’t approved in the U.S. and aren’t backed by solid evidence of effectiveness from well-designed clinical trials.

Insurance typically doesn’t cover these unproven therapies, and patients may spend thousands of dollars out-of-pocket on stem cell therapies that don’t deliver promised benefits and may even leave patients worse off than before.

When clinics advertising unproven stem cell therapies promise that U.S.-trained physicians are providing these treatments, patients may be lulled into a false sense of security even when these doctors aren’t trained to provide the advertised services.

For the current study, researchers examined the training background of 608 clinicians at 166 companies advertising unproven stem cell therapies in California, Florida, and Texas.

Overall, 401 clinicians, or 66per cent, were physicians.

Out of 157 companies with a physician on staff, only about half had at least one doctor with training in the specialty needed for the type of services offered to patients.

Among orthopedic-focused practices, 77per cent had one or more physicians with the appropriate training in this specialty.

For other types of unproven stem cell therapies, only 19per cent of companies advertising services appeared to have physicians on staff with the appropriate training.

Many clinics were also staffed by other types of clinicians like nurses, physician assistants, podiatrists, physical therapists, dentists, and scientists.

The study focused on unproven treatments that might be ineffective and dangerous regardless of physicians’ training. It wasn’t a controlled experiment designed to prove whether or how clinician training might directly impact patient outcomes.

“Reports of serious harms, including septicemia, blindness, paralysis and death, have been increasing in recent years,” said Douglas Sipp, a researcher at RIKEN Center for Developmental Biology in Kobe, Japan, who wasn’t involved in the study.

“But even when such treatments are performed without incident, the main risk is that the patient will receive no more than an expensive, medically useless placebo,” Sipp said by email.

Unproven stem cell injections aren’t in the best interest of patients and stem cells really are not at present advisable for any medical conditions besides those already established related to blood cancers and immune disorders, said Paul Knoepfler, a professor of cell biology and human anatomy at the University of California Davis School of Medicine in Sacramento.

“Even so, the potential profits and/or illusions about the purported magic of ‘stem cells’ is clearly luring some doctors into dangerous territory outside their expertise,” Knoepfler said by email.

“Injecting unproven stem cells into patients who have health conditions outside the doctors’ area of expertise (e.g. say a dermatologist treating a brain condition) is riskier for the patient, but a surprising number of physicians are willing to do it anyway,” Knoepfler added. “They’re rolling the stem cell dice with their patients because these doctors either have unrealistic notions about the “alternative medicine” power of stem cells or the extra profit is attractive.”