HELENA, Mont. - A Montana advocacy group is shutting down its traveling medical marijuana clinics amid criticism that the so-called cannabis caravans have added thousands of people to the state registry without conducting thorough patient screenings.

The Montana Caregviers Network has hosted the one-day clinics in hotels and conference centers across Montana for more than a year. For a $150 fee, the group brought together those seeking to become medical marijuana patients with doctors willing to prescribe pot.

Starting this week, the group will forgo the clinics and instead team up with medical marijuana distributors - called caregivers in Montana - to provide regular doctor's office hours in Billings, Bozeman and Helena, in addition to the group's base in Missoula.

"It is being changed partially because of the criticism of the traveling clinics. Also, from the business end, it's no longer sustainable," group spokesman Chris Arneson said. "The traveling clinics no longer allow us to serve our patients the best we can."

The clinics were a major factor in Montana's medical marijuana patient registry jumping from 842 people at the end of 2008 to just about 20,000 at the end of June. The clinics have also helped the Montana Caregivers Network make more than $1 million in the past year, according to founder Jason Christ.

The clinics often had lines stretching out the door, with hopefuls waiting hours for the chance to see a doctor for a recommendation.

But over the past few months, the clinics have come under criticism as being assembly lines that sees hundreds of people at a time, but at the expense of proper medical examinations.

An interim legislative committee drafting a bill to shore up the state's medical marijuana law has been hearing from people who say the pot boom goes against the aim of the law to provide care to people with the most debilitating illnesses or conditions.

"What did the voters think they were voting for and can we get back to those basic issues of providing limited, controlled access for people who the public thought really needed this as compassionate care?" said Chairwoman Diane Sands, D-Missoula, in outlining the committee's aim in drafting the bill.

Meanwhile, the state medical board tried to curtail the mass screenings with a position paper released at the end of May saying that doctors who recommend medical marijuana must follow the same standards as doctors prescribing other medicine.

The board fined a physician who had seen about 150 people in 14 hours at one of those clinics last year.

Arneson acknowledged that the medical board's actions factored into the change, but said it wasn't the only reason. The group is also anticipating more than 10,000 current patients will be seeking renewals to their one-year registration cards this fall.

The group's new model seeks to establish hubs in the state's largest cities that will service both new patients and renewing ones.

The Montana Caregivers Network has a doctor who now works full-time with the group in Missoula. He will go to Billings, Bozeman and Helena once a week to provide recommendations for new patients and for current ones seeking to renew their one-year eligibility, Arneson said.

The doctor will operate out of a caregiver's office in each of those cities. When there aren't any patients to see, the doctor will consult with would-be patients in other parts of the state through "teleclinics" conducted over the Internet via Skype, Arneson said.

The doctor will spend as much time as necessary with each patient, and the organization will not set a quota or limit the number of patients that can be seen in a day, Arneson said.

The Montana Caregivers Network will still handle the records and still charge $150 per recommendation.