Several months ago, a pharmaceutical company salesman told Dr. Mario Motta something that surprised him. The salesman, who had scheduled a 15-minute appointment with Motta, said he knew that the doctor had been prescribing a competitor's cardiac drugs - and he wanted Motta to switch.

Motta had never discussed his personal prescribing habits with the salesman. "I said, 'How would you know that?' " Motta recalled. "I couldn't get it out of him, so I told him to leave."

Drug makers, in a level of detail unknown to many physicians, are spending millions of dollars to develop secret reports about individual doctors and their patients, according to consultants to the drug companies.

Most physicians know drug companies collect some information about which medications they prescribe. But they are often surprised by the depth of detail pharmaceutical makers now are buying about almost every US physician, mostly from large pharmacy chains. The details include whether doctors are switching specific patients from one drug to a competitor within days of it happening, and whether they treat many poor patients and may want free samples.

With many doctors now holding sales representatives to strict time limits when they visit, these "prescriber profiles" allow reps to tailor their pitches to individual physicians. They are an increasingly important tool in drug company marketing to doctors, which accounts for the largest portion, $16 billion, of the $19 billion that pharmaceutical companies spent on marketing in 2001, according to IMS Health, a Connecticut-based compmany that collects prescriber data.

"Average sales calls are shorter, and physicians are seeing fewer sales reps," said E.M. "Mick" Kolassa, a professor at the University of Mississippi and managing partner of Medical Marketing Economics, which provides consulting services to drug companies. "Because of this, the sales call has become a more precious commodity and companies need to make sure they're putting their resources in the right place."

But even though patient names are removed from the data, some doctors believe these secret reports - which they say sales reps almost never discuss openly with them - are an unwelcome intrusion into the doctor-patient relationship. Doctors worry that the reports allow sales reps to push expensive drugs more effectively in a health care system that already is struggling with soaring costs.

"The amount of information they have about us and our prescribing is staggering," said Dr. Mark Rohrer, an internist and geriatrician at St. Elizabeth's Medical Center in Boston. "The important thing is how it's used. If it's used by a rep to pressure me to provide a different drug than the one I'm prescribing, especially if there's a generic alternative, I don't think that's right."

Several drug makers, including Eli Lilly and Wyeth, and the Pharmaceutical Research and Manufacturers of America, the industry trade group, would not comment on prescriber profiling.

Michael Barnes, vice president of business intelligence solutions at Dendrite International Inc., which provides prescription data to drug companies, said the data are used to promote safety.

For instance, the Food and Drug Administration buys Dendrite's prescribing data, which allows the agency to monitor cases in which large groups of patients are taking drugs that could have dangerous interactions, he said. The agency can then direct the company to educate doctors about the potential harm.

Prescriber profiles, albeit in a more rudimentary form, are a key element in the whistle-blower lawsuit David Franklin filed against his former employer, Parke-Davis, now part of Pfizer, alleging illegal and off-label marketing of the company's top-selling epilepsy drug, Neurontin. Federal investigators are in settlement talks with Pfizer, which declines to discuss the case.

Franklin, who worked as a medical liaison for Parke-Davis from April to July 1996, said his supervisors would provide him with a doctor's prescribing record for the previous month before he went on a sales call.

A month later, they would send him the physician's new prescriptions, so he could see if the information he gave to the doctor led him to prescribe more Neurontin or other Parke-Davis drugs. Now sales reps can see within days if a doctor is responding to a pitch, he said.

If a doctor was prescribing a competitor's product, Franklin knew that his presentation should focus on undermining that product, he said.

Sales people also reviewed doctors' prescribing habits to determine who was loyal and should receive trips and gifts. The industry has since put in place voluntary guidelines discouraging lavish trips and gifts.

"The doctors it didn't work on didn't get the gifts anymore because it was throwing money away," he said. "Your physician would be stunned to find out what pharmaceutical reps know about them before they walk into the office. We were trained in how to use this information without letting the doctor know we had it. It was absolutely imperative that you never referred to the report."

Documents recently unsealed in Franklin's lawsuit in US District Court in Boston also show Parke-Davis conducted prescriber profiling to determine whether dinner meetings, lectures, and teleconferences persuaded physicians who attended to prescribe more Parke-Davis drugs. Sometimes it worked, according to the company's analyses, and sometimes it didn't.

Since the mid-1990s, drug companies have hired outside firms that purchase data on physicians from pharmacies and used the information in marketing. It's legal in the United States as long as patients are not identified. However, the Canadian province of British Columbia outlawed the practice in 1996. But in the last two years, the data have gotten more sophisticated.

"What's really changed in the last year or two is the speed at which they can get it," Kolassa said.

Companies that buy data and sell it to drug makers are creating and advertising new products.

Verispan, based in Pennsylvania, promises on its website that a new product called Market Mover will deliver changes in doctor prescribing behavior four days after the close of the week. It's "the fastest available indicator of changes in individual prescribing behavior," the company says. The company now sends these prescriber "alerts" directly to the sales rep's laptop. Verispan executives would not discuss prescriber profiling.

Companies such as IMS Health purchased computer records or tap directly into the pharmacy computer and extract information on the 3 billion prescriptions US pharmacies fill annually, according to industry specialists. They combine this information with biographies on nearly 850,000 physicians compiled by the American Medical Association, which earns $30 million annually licensing detailed reports on physicians, including where they went to medical school, their fax numbers, and their specialties. About 20,000 doctors have opted to be removed from the list.

AMA past president Dr. Richard Corlin said the list serves an important safety function: It allows drug companies to immediately alert doctors to a problem with a drug or change in how a medication should be used. But after some of its own members began criticizing the AMA for providing the list for marketing purposes, the organization a year ago adopted guidelines for drug companies that license the data, saying they should not use it to pressure doctors to change drugs.

AMA officials said they would consider suspending a licensing agreement with any drug company that violated these guidelines, but that they haven't received any complaints from doctors to that effect.

Verispan, IMS, and other companies also now buy data not just on individual doctors, but on individual patients and the medications they're taking. Executives at CVS and Walgreens, as well as Dendrite's Barnes, said pharmacies remove patient names and identifying details from the data and assign each person a non-traceable number. But the data include information such as a patient's insurance provider, all the drugs a patient takes, and the doses. Pharmacies would not say how much they charge for the data.

Barnes said the patient data are crucial because they follow individual patients, so drug companies can see whether doctors are merely placing new patients on a competitor's drug or whether they're actually switching existing patients off one drug and onto another - a greater cause for alarm.

If a drug company, for example, finds doctors are switching patients off of its cholesterol-lowering drug after they don't respond to a 40-milligram dose, the company can direct its sales force to focus on telling doctors to increase the dose.

With doctor-specific data, drug companies could tell only if a doctor was writing more prescriptions for a particular medication, but nothing about who was getting the drugs. The patient-specific data allow drug companies to see changes in physician prescribing behavior eight months sooner, "which could save tens of millions of dollars for the company," Barnes said.

Barnes said the more advanced data also are used to promote safety. The FDA buys Dendrite's prescribing data, for example; this allows the agency to monitor cases in which large groups of patients are taking drugs that could have dangerous interactions. The agency can then direct the company to educate doctors about the potential harm.

But even when it comes to pure marketing, Kolassa said he doesn't believe prescriber profiling is unethical. "It's done throughout business. Frito-Lay knows a lot more about you than Merck knows about individual physicians. They know whether you bought beer or Diet Coke with your corn chips. Besides, physicians can always tell sales reps to take a hike."