Results Summary
What was the research about?
Obesity can lead to serious health problems such as high blood pressure, diabetes, and heart disease. Doctors offering different treatment choices may help patients with obesity lose weight.
In this study, the research team wanted to see if giving patients a choice of one or more weight-loss treatments helped them lose weight. The team offered five options:
- Meal replacements
- Weight-loss medicines
- Weight Watchers® vouchers
- Recreation center passes
- Group lifestyle classes
Patients could choose one option at the start of the study and change or add options after six months. The research team compared the results for patients who used a weight-loss treatment to those who did not.
What were the results?
Over the course of the study, more patients who used a weight-loss treatment lost weight than patients who didn’t use a treatment. A total of 35 percent of patients who used a weight-loss treatment lost at least 5 percent of their weight. Only 16 percent of the patients getting usual care lost that much.
Patients who used a weight-loss treatment were more likely to lose at least 5 percent of their weight if they
- Went to more of their monthly doctor visits
- Added a second weight-loss treatment
- Chose to take a weight-loss medicine
Of the patients selecting a treatment
- 35 percent chose meal replacements
- 28 percent chose weight-loss medicines
- 22 percent chose recreation center passes
- 7 percent chose Weight Watchers® vouchers
- 5 percent chose group lifestyle classes
- 2 percent wanted only monthly clinic visits
During the study, 55 percent of patients who selected a treatment changed that treatment at least once. As the study went on, more patients changed to medicines. More patients switched from meal replacements or recreation center passes than the other choices.
Who was in the study?
The study included 3,049 patients with obesity and at least one related health problem. Patients attended any of eight clinics serving patients with low incomes in the Denver, Colorado, area. Of the patients offered the choice of a treatment, 82 percent were white, 17 percent were black, and 1 percent were Native Indian or Alaskan. A total of 55 percent of patients identified as Hispanic or Latino. The average age was 50 and 70 percent were women.
What did the research team do?
Using health records, the research team created a list of patients with obesity from the eight healthcare clinics. The team assigned patients to one of two groups by chance. Patients in one group chose from a set of weight-loss treatments that the team had already found to work well. Of these 309 patients, 119 chose at least one treatment. During the one-year study, these patients visited a clinic and got weighed once a month. Patients choosing a treatment had to pay a $5 or $10 copay each month.
Patients in the second group received usual care and visited their doctors at least once during the study. The doctors gave patients information about a weight-loss treatment only if they asked for it. Of these patients, 12 percent asked their doctor for information about a weight-loss treatment, and the doctors provided it.
The research team collected weight information from patients’ health records. In addition, the team looked at health records to see what weight-loss program choices patients in the treatment group made.
What were the limits of the study?
The study included patients from only one healthcare system. The results may be different for patients in other places.
Future studies could look at whether patients’ health conditions improve because of their weight-loss choices.
How can people use the results?
Doctors can use the results when considering similar ways to help patients lose weight. Health insurance companies could include these weight-loss-treatment choices in their plans.
Professional Abstract
Objective
To examine weight loss in patients with obesity who chose among five research-based weight-loss treatments in a primary care setting, compared with weight loss in patients with obesity who received usual primary care services
Study Design
| Design Element | Description |
|---|---|
| Design | Randomized controlled trial |
| Population | 3,049 adult patients with obesity receiving care at 8 clinics |
| Interventions/ Comparators |
|
| Outcomes |
Primary: loss of at least 5% of initial body weight Secondary: use of specific weight-loss treatments |
| Timeframe | 1 year follow-up for primary outcome |
This registry-based pragmatic randomized controlled trial compared outcomes from a multioption weight-loss program integrated into primary care with outcomes from usual primary care.
Researchers created a registry of 3,049 patients with obesity from eight primary care clinics within a healthcare organization in Denver, Colorado. Patients had a body mass index of 30–45, had at least one weight-related comorbidity, and were ages 18–80. Researchers randomly selected 309 patients from the registry and recruited them to participate in the intervention group. Of these, 119 patients, or 39% of the group, selected at least one weight-loss intervention.
Primary care doctors offered patients the choice among five treatment options: replacement meals, pharmacotherapy using phentermine or phentermine/topiramate extended release, recreation center passes, Weight Watchers® vouchers, and group behavioral weight-loss classes. Patients could switch treatments at a monthly office visit or add an additional treatment after six months. Treatment options required a $5 or $10 copay at each monthly visit.
The usual care group included 2,640 patients from the registry. Of these patients, 12% requested information about a weight-loss treatment, and the doctors provided it.
In the intervention group, 82% of the patients were white, 17% were black, and 1% were Native Indian/Alaskan. In addition, 55% identified as Hispanic or Latino. The average age was 50, and 70% were female.
Researchers collected body weights monthly for patients in the intervention group and at regularly occurring office visits for the usual care group. The researchers used medical records to determine patients’ weight loss and treatment selections.
Before and during the trial, researchers obtained input about the study from patients and primary care doctors. Researchers used the input to improve their interactions with patients and clinic personnel.
Results
Weight loss. Of the patients who selected one of the five treatments, 35% lost at least 5% of their body weight, compared with 16% in the usual care group (p<0.001). Patients who attended more office visits, added a second weight-loss treatment, or used pharmacotherapy were more likely to lose weight than those who selected other treatments.
Selection of weight-loss options. Among the five options, approximately 35% of patients chose meal replacements, 28% chose weight-loss medications, 22% chose recreation center passes, 7% chose Weight Watchers® vouchers, and 5% chose behavioral weight-loss classes. Another 2% wanted to attend monthly clinic visits only.
Throughout the study, 42% of patients chose only one treatment option, 44% selected two options, and 13% chose three or more options. After six months, 29% of the patients in the intervention added an additional treatment to their original choice. During the study, the choice of weight-loss medications increased, and the choice of meal replacements and recreation center passes decreased.
Limitations
The study included patients from eight primary care clinics in a single healthcare system. Results may not be generalizable to other populations.
Conclusions and Relevance
Compared with usual care, a choice of research-based weight-loss treatments for patients with obesity and at least one weight-related comorbidity in the primary care setting resulted in more patients achieving a loss of at least 5% of their body weight after 12 months.
Future Research Needs
A longer study may reveal the effects of weight loss on comorbid health problems and cardiovascular risk factors. Future studies may also offer information about predictors of success for certain patient subpopulations with respect to specific treatments or treatment combinations.
Final Research Report
View this project's final research report.
Journal Citations
Results of This Project
Related Journal Citations
Peer-Review Summary
Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.
The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.
Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:
- The reviewers asked for more information about the weight-management interventions that were already being used in the comparison group and how those were assessed. The researchers explained in their revision that they used chart review to identify what interventions were used in the comparison group.
- Given the pragmatic, not-randomized nature of this trial, the reviewers asked for more detail on how the researchers accounted for potentially confounding variables. The researchers added information to describe how they used generalized linear mixed models to address confounders.
- In a related comment, the reviewers expressed concern that the researchers did not adequately address differences among the study sites and differences in the number of observations and number of clinic visits per patient. The researchers described how they addressed these concerns. They also stated that they had looked for any differences in non-study-related visits between groups and found none.
- The reviewers asked for more information on how the researchers measured patient adherence to the treatment modality. The researchers explained that they measured adherence based on visits to the weight clinic, group weight-loss classes, and the recreational center. They were unable to use other types of adherence measures because clients were inconsistent in their use of reporting tools.
- The reviewers stressed the importance of addressing the PCORI Methodology Standards related to data registries in the final report. The researchers provided this information, noting in their response that they had added information about how they dealt with patients who dropped out, were excluded, or were lost to follow-up.