Characteristics and Scope of Training of Clinicians Participating in the US Direct-to-Consumer Marketplace for Unproven Stem Cell Interventions

More than 700 US clinics advertise unproven stem cell treatments.¹ Hematopoietic stem cell transplants to treat various hematologic disorders are evidence-based whereas most other stem cell interventions are investigational. This study examined the characteristics and scope of training of clinicians performing unproven stem cell procedures.

Through systematic internet searches and content analysis, a 2016 study identified 351 US companies marketing unproven stem cell procedures provided at 570 clinics. The largest concentrations of companies were in California, Florida, and Texas.² Focusing on companies in these 3 states and identified in the 2016 study,² we excluded companies that ceased marketing stem cell procedures by January 2018. From company websites, we extracted information related to characteristics and training of all identified professionals. For physicians, we examined state medical board licensing databases to confirm qualifications and compared information obtained from the Federation of State Medical Board (FSMB) Physician Data Center (PDC). The PDC contains specialty board certifications from the American Board of Medical Specialties (ABMS), whereas most information in state medical board databases is self-reported. When discrepancies were found, information from the PDC was used.

To determine scope of training, 2 coders with medical expertise (W.F. and J.F.) used their judgment to independently review conditions each company claimed to treat and determined whether at least 1 physician at the company had the appropriate residency or fellowship training required to treat such conditions. Given the prevalence of companies treating orthopedic indications with stem cells, we compared orthopedic with nonorthopedic facilities using a 2-sided χ² test calculated using JMP Pro14 (SAS Institute Inc), with a P < .05 considered statistically significant. Companies were classified as orthopedic if they exclusively treated orthopedic conditions based on the ABMS Guide to Medical Specialties³ and the judgment of both coders. Coders recognized that different specialists could treat the same conditions. Generalists were considered not to have specialty training to administer advanced stem cell procedures. Coders were in all cases able to reach agreement concerning company classification and scope of training.

Of 183 identified companies, 166 continued to advertise in 2018. In total, 608 clinicians were identified, of whom 401 (66%) were physicians. Physician assistants, nurses, and complementary and alternative medicine practitioners were the most common nonphysicians (Table 1). Five companies were staffed completely by podiatrists, 2 by naturopaths, 1 by dentists, and 1 by practitioners with unclear qualifications. Forty percent of companies were solo practices; 27% had 2 to 3 practitioners; 14%, 4 to 5 practitioners; and 19%, 6 or more practitioners.

Among the 401 physicians, 91.5% were male and 80.5% completed medical training in the United States. Physicians represented 20 different types of residencies, including orthopedics (30.8%), anesthesiology (15.9%), physical medicine and rehabilitation (10.8%), and family medicine (10.4%) (Table 2). Physicians completed training in 25 different fellowships, including orthopedics (28.5%), sports medicine (24.3%), and pain medicine (21.8%) (Table 2).

Of the 157 companies with a physician, 81 companies (52%) that advertised stem cell treatments had at least 1 physician with formal training matching the conditions claimed to treat. Among orthopedic-focused practices, 68 (77%) had 1 or more physicians with appropriate specialty training. Only 13 companies (19%) that marketed stem cells for nonorthopedic indications had physicians practicing within their scope of training (P < .001).

Many clinicians provided stem cell interventions for conditions outside their scope of training. Unlicensed stem cell interventions pose risks.⁴ Clinicians practicing beyond their scope of training could increase risks to patients.⁵

This study has several limitations. The analysis was limited to clinicians from 3 states and did not include clinicians who entered the marketplace after 2016. Assessing scope of training relied on coders’ judgment based on residency and fellowship training and did not consider that some physicians may have additional training. Scope of training was underestimated because it was defined at the company level.

In 2018, the FSMB⁶ reported that 17 of 51 boards investigated complaints, and 8 took disciplinary actions related to physicians’ performing unlicensed stem cell procedures. State medical boards should consider investigating licensees suspected of violating professional standards when providing unproven stem cell interventions, especially those advertising treatment outside their scope of training.

Accepted for Publication: April 17, 2019.

Corresponding Author: Zubin Master, PhD, Biomedical Ethics Research Program, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (master.zubin@mayo.edu).

Author Contributions: Drs Fu and Master had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Fu, Smith, Turner, Master.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Fu, Turner, Master.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Pacyna.

Obtained funding: Master.

Administrative, technical, or material support: Fu, Fojtik.

Supervision: Master.

Conflict of Interest Disclosures: Dr Fojtik reported that he was part of the FSMB Workgroup to Study Regenerative and Stem Cell Therapy Practices. Dr Master reported that he was part of the FSMB Workgroup to Study Regenerative and Stem Cell Therapy Practices and received nonfinancial support and grants from the FSMB during the conduct of the study. No other disclosures were reported.

Funding/Support: This research was supported through an FSMB Foundation grant (Dr Master). Dr Fu received support from the Richard T. Beebe, MD, Fellowship.

Role of the Funder/Sponsor: The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: We thank the FSMB’s research team for providing information from the PDC. For helpful discussion, we thank Scott Steingard, DO, and Gregory B. Snyder, MD, of the FSMB and Shane Shapiro, MD, of the Mayo Clinic Florida, none of whom were compensated for their feedback.