Little is known, however, about patients’ willingness to take weight loss medications or the minimum weight loss they expect to lose to make pharmacotherapy worthwhile. Only a few studies have investigated patient willingness to adopt pharmacotherapy as part of a weight loss regimen, and only one investigated obese patients in the United States [8]. In this context, we surveyed a sociodemographically diverse group of primary care patients with moderate to severe obesity to examine patient characteristics associated with willingness to pursue weight loss pharmacotherapy. We also aimed to evaluate how much weight patients expected to lose in order to make taking a daily medication worth the effort. Characterizing patients seen in primary care who are willing to adopt pharmacotherapy to lose weight may guide weight loss counseling in the primary care setting. Furthermore, determining whether patients have realistic weight loss expectations can help clinicians better counsel their patients on weight loss goals.
Methods
Study Sample
We recruited 337 subjects from 4 diverse primary care practices in Boston, Massachusetts: a large hospital-based academic practice, a community practice in a working-class suburb, a community practice in an affluent suburb, and a health center serving a predominantly socially disadvantaged population. The primary goal of the parent study was to understand the preferences of patients for weight loss treatment, especially bariatric surgery. Therefore, to be included, patients needed to have a BMI ≥ 35 kg/m 2 at the time of recruitment, been seen in clinic within the past year, be aged 18–65 years, and be English or Spanish speaking. By design, African-American and Hispanic patients were oversampled from an electronic list of potentially eligible patient groups so that we could examine for racial differences in treatment preferences. Study details have been previously described [9].
Data Collection and Measures
Trained interviewers conducted a 45- to 60-minute telephone interview with each participant in either English or Spanish. To assess willingness to use a daily weight loss medication, subjects were asked, “If your doctor recommended it, would you be willing to take a pill or medication every day in order to lose weight?” Those who answered affirmatively were then asked the minimum amount of weight they would have to lose to make taking a pill everyday worthwhile.
Subjects were also asked about demographic information (age, race, education, marital status) and comorbid health conditions commonly associated with obesity (diabetes mellitus, hypertension, asthma, obstructive sleep apnea, GERD, depression, anxiety, back pain, and cardiovascular problems). We assessed quality of life (QOL) using the Impact of Weight on Quality of Life-Lite (IWQOL-Lite), a 31-item instrument designed specifically to assess the impact of obesity on QOL capturing 5 domains (physical function, self-esteem, sexual life, public distress, and work). Subjects were asked to rate a series of statements beginning with “Because of my weight…” as “always true,” “usually true,” “sometimes true,” “rarely true,” or “never true.” Global and domain scores ranged from 0 to 100; higher scores reflected better QOL [10].
Data Analysis
We used descriptive statistics to characterize the proportion of subjects willing to use a daily weight loss medication and the weight loss required for patients to be willing to consider pharmacotherapy. We used a stepwise logistic model to examine demographic, QOL, and clinical factors associated with the willingness to take a weight loss medication as the outcome, with an entry criteria of P value of 0.1 and an exit criteria of 0.05. Log-Poisson distribution using the sandwich estimator was used to obtain relative risks for each significant variable. Adjusted models included age, BMI, sex, and race and any significant comorbidities. We added overall QOL score and individual QOL scores in subsequent models to examine the relative influence of overall vs. domain-specific QOL. Statistical analyses were conducted with SAS (SAS Institute, Cary, NC). We considered the change in model C-statistic when specific variables were added to the model to determine the importance of these factors in contributing to patients’ willingness to consider pharmacotherapy; larger changes in model C-statistic signifies a greater contribution.