A study recently published in JAMA Dermatology looked into telemedicine companies, and the Wall Street Journal reports that researchers found many physicians failed to ask important questions, and subsequently misdiagnosed and mistreated certain conditions.

The study covered 16 companies—nine of which were specific to dermatology while the remaining seven were general medicine websites—totaling in 62 visits. According to the American Telemedicine Association (ATA), there are 200 networks and 3,500 service sites in the U.S., and the group is expecting more than 1 million online consultations this year.

Researchers created six scenarios, including detailed medical histories, and used stock photos to pose as patients. Of 62 visits, 48 patients were diagnosed and 31 were prescribed medication. Only 10 were warned about potential risks and side effects, 13 were asked about their primary care physician, and six were offered to have records of the consultation sent to their doctor, according to the study.

Diagnoses tended to be correct when a condition was identifiable based on photos alone. Clinicians were less successful when it was a more complex condition that required additional information.

“The services failed to ask simple, relevant questions of patients about their symptoms, leading them to repeatedly miss important diagnoses,” dermatologist and lead author Jack Resneck told the Journal. The study admitted it couldn’t say whether visits would have been more successful had patients seen a doctor in person, though Resneck said, “The usual give-and-take that occurs between a physician and a patient wasn’t happening.”

ATA CEO Jonathan Linkous agreed with the study’s conclusions that quality control is necessary. However, telemedicine is a fairly new practice and, as he told the Journal, the group only began an accreditation program last year. Of the 500 companies that have applied, just seven have been approved so far.