Randomized Trial of a Patient Decision Aid for Bariatric Surgery

Purpose

The specific aims of this randomized control trial are to formally evaluate the impact of the “Weight loss surgery: Is it right for you?” Shared Decision-Making® program on decision quality in primary care and bariatric specialty practice settings, following the approach recommended in the Cochrane CREDIBLE Criteria for Decision Aids among morbidly obese adults enrolled at Group Health.

For the past year, the specific aims were to:

Specific aim 1: Determine if the bariatric decision aid resulted in superior bariatric surgery decision quality than an NIH booklet on weight loss surgery (“usual care”).

Specific aim 2: Determine if the bariatric decision aid resulted in less decisional conflict and superior decisional self-efficacy than usual care.

Specific aim 3: Determine whether the effect of the interventions on decision quality differed among treatment seekers and non-treatment seekers.

Specific aim 4: Investigate medical, psychological and behavioral factors as mediators of treatment choice.

The secondary aims of this study were to:

Secondary aim 1: Understand the current weight control attitudes and practices among morbidly obese patients who are not actively seeking bariatric surgical treatment.

Secondary aim 2: Assess the rates of bariatric surgery, health care costs, health care use and outcomes, and changes in BMI over time across the intervention groups, as well as across study subgroups such as those who did and did not choose to have bariatric surgery.

Findings

Overall, both of the bariatric surgery decision aids (Shared Decision-Making® program and NIH booklet) were each associated with improved decision quality and a decrease in uncertainty about treatment choices at three months follow-up.

At three month follow-up, it does not appear that there was a significant differential impact of the two decision aids on subjects’ decisions to have surgery; however, it will be important to continue to follow subjects in both groups to see what their ultimate treatment decisions will be. The trial has IRB approval to follow the individuals in the study for three years to observe their health care use, to conduct follow-up analyses at the end of this period to explore the impact of our interventions on subjects’ ultimate decisions whether or not to have surgery.

The Shared Decision-Making® program appeared to have a greater impact on patient knowledge, decisional conflict and outcome expectancies than the NIH booklet. Overall, these outcomes suggest that the video decision aid has a superior effect on decision quality. Notably, however, there was no difference in values concordance between our two decision aids at three months. It is unclear why the video was unable to outperform the booklet in this domain. The results suggest that the video group experienced a more rapid, early improvement in value concordance immediately after the intervention, but that the intervention groups had similar gains in value concordance at three-months.