Predictors of weight control advice in primary care practices: patient health and psychosocial characteristics

Abstract

Background. Past research has surveyed primary care physicians (PCP) about their attitudes and practices towards obese patients, yet less is known about the patients receiving advice.

Methods. The Primary Care Weight Control Project (PCWC) enrolled 18 PCPs in a randomized clinical trial and asked 255 of their patients who were either overweight or obese at baseline about past weight control advice.

Results. At baseline, 66.4% of patients reported that their physician previously told them they were overweight. Body mass index (BMI) was a strong predictor of being identified as obese. While 65.1% received information on the health benefits of weight loss, only 36.6% of patients were ever given specific weight control advice, and 28.2% were advised to increase their physical activity. A history of type 2 diabetes, high cholesterol, or hypertension was associated with physician-delivered weight control advice. Stages of change and number of prior visits with the PCP were also associated with physician advice.

Conclusions. Patients were more likely to receive education about weight loss than specific behavioral advice on how to lose weight. Physicians were more likely to provide weight control advice to their patients who had obesity-related comorbidities than to patients who were overweight or obese and without risk factors.

Introduction

Significant increases in the prevalence of obesity have occurred across geographic regions, gender, age, racial groups, and education levels [1]. Obesity-related health conditions include hypertension, type 2 diabetes, coronary heart disease (CHD), gallbladder disease, osteoarthritis, sleep apnea and respiratory problems, and some types of cancer [2]. In addition to the serious health consequences, adolescents and young adults who are obese may suffer from social stigmatization which can affect future educational attainment, professional opportunities, and earning potential [3]. Because obesity is associated with a number of serious and chronic health conditions, its economic costs in terms of morbidity and mortality are high. The direct costs alone associated with obesity are thought to represent 5.7% of the country's national health expenditure [4].

Although treatment guidelines for physicians are available, in practice, overweight and obesity are underrecognized and only a modest percentage of patients are counseled about their excess weight. For example, data from the (1995–1996) National Ambulatory Medical Care Survey indicated that physicians reported obesity in only 38% of their obese patients and provided weight counseling to only 36% of those identified as obese [5]. Similar findings based on the (1996) Behavioral Risk Factor Surveillance System (BRFSS) have been published showing that less than half of obese adults who visited their physician for a check-up during the 12-month time frame of the survey were advised to lose weight [6], [7].

Physicians may be more or less likely to identify patients as overweight or obese and discuss weight control depending on patients' health and sociodemographic characteristics.

Patient factors associated with being identified or diagnosed as obese by their physician include high body mass index (BMI) [8], [9], low education level [9], smoking status [5], and female gender [5], [8], [9]. BMI has been found to be a predictor not only of obesity identification, but also of who receives counseling [6], [7]. BMI, however, is highly correlated with type 2 diabetes, high cholesterol, and high blood pressure, and physicians may be more likely to discuss weight control with patients who are being treated for these chronic medical conditions [6], [7]. The finding that those patients whose health is compromised by their extra weight are more likely to receive weight counseling is consistent with studies in physical activity promotion [10].

Whereas having less education may be associated with being identified as obese by a physician [9], being more educated and having a higher income may be associated with being counseled about diet and exercise [11]. Regarding gender, physicians may tend to address weight control issues more often with women than men [6], [7], [8]. Studies are mixed, however, regarding the age of the patient with some finding younger patients more likely to be identified as obese [5] and counseled [9], and other studies finding middle-aged or older patients more likely to be counseled [6], [7].

While the research on patient factors and physician-delivered weight control counseling is evolving, studies have been limited by exclusive use of physician report, patient medical record, or patient recall. Details on the content of weight control counseling or advice given to patients who are obese are also lacking. Moreover, previous research tends not to statistically control for the potential clustering within a single physician's set of patients. In studies where the physician is the unit of analysis, one would expect the physician effect to be considerable.

The present study provides a detailed examination of baseline data from the Primary Care Weight Control Project (PCWC Project), a randomized clinical trial evaluating the efficacy of treating obesity in the primary care setting. This paper reports the prevalence of past physician-delivered weight control advice and identifies predictors of obesity identification and weight control advice. Predictors of interest included BMI, waist circumference, physical activity level, dietary intake, mood, motivational readiness for weight control, number of past visits with primary care physicians (PCP), patient self-reported medical history, and selected sociodemographic characteristics. History of weight control advice provided by the PCP was assessed by both patient self-report and by review of the patient's medical record.