NY Times, October 25, 2010
By NICHOLAS BAKALAR
People who are overweight are often counseled by their physicians to lose the extra pounds. But does such advice do any good? A new study suggests that it depends on the way it is offered Cajoling and coaxing, scolding and reproach are all ineffective, the researchers found. But collaborative discussion may actually work.
The researchers recorded conversations between 40 primary-care doctors and 461 of their overweight or obese patients over an 18-month period ending in June 2008. They noted whether any of three weight-related subjects came up: nutrition, physical activity, or weight and body mass index. Then they followed up three months later to see if the talk about weight actually resulted in any weight loss.
Most of the doctors brought up the subject of weight, and 320 of the 461 patients listened to at least some discussion of the problem. Then, after noting the amount of time the doctors spent on the subject, the researchers used a well-tested scale to rate the conversation’s motivational content.
Motivational interviewing is an approach that enlists patients’ own drive for change, and emphasizes that change can come only from the patient, not from the doctor. It accepts patients’ weaknesses, praises success and puts the doctor and patient in a collaborative effort.
A nonmotivational talk, by contrast, typically includes confronting, judging, persuading and offering advice without having been asked for it. According to background information in the article, which appears in the October issue of The American Journal of Preventive Medicine, motivational interviewing has been found effective for reducing alcohol use and smoking, and has shown some promise in weight loss.
Statistical analysis showed no significant difference between the patients who had discussed the weight problem with their doctors and those who had not. Three months later, most patients were almost exactly the same weight or heavier.
But looking only at the 320 patients who had discussed weight, they found that a motivational interview was associated with a significant weight loss — 3.5 pounds more than those who had had a nonmotivational conversation. The difference persisted even after controlling for age, race, sex, economic status, educational level, general health and other factors.
Dr. Nicolas Rodondi, an assistant professor of medicine at the University of Lausanne in Switzerland, who has published widely on weight and health but was not involved in the current work, called the study “good and interesting.” But he hesitated when asked about the enduring effect of motivational interviewing.
“The timing of three months is instructive,” he said, “but it remains to be proven whether it will translate to long-term weight loss.”
The lead researcher, Kathryn I. Pollak, an associate professor of community and family medicine at Duke, pointed out that most of what doctors say to patients is expert advice, offered prescriptively: take this pill, rest in bed, call me in the morning. But this kind of direction does not work to change behavior.
“When it comes to behavior change, the patient is the expert, not the doctor,” she said. “The whole point is to help the patient solve the problem himself. Doctors have to see the difference between behavioral counseling and the rest of their job.”
Neither patients nor doctors knew at the outset that the study was about weight, and the sample was fairly large — two factors that lend strength to the conclusions. On the other hand, the observational design, the fact that medication use was not tracked, and the lack of younger and lower-income patients limit the conclusions that can be drawn.
Also, the authors acknowledge that a three-month study says nothing about the effectiveness of motivational interviewing over the long term.
Dr. Pollak said there was no question that doctors paid attention to the problem — in this study, the doctors who mentioned weight spent almost 15 percent of their time on the subject.
“Doctors are hearing the message that they need to do something,” she said. “They’re trying, but they’re not doing it right.”