Prioritising patients for bariatric surgery: building public preferences from a discrete choice experiment into public policy

Abstract

Objectives: To derive priority weights for access to bariatric surgery for obese adults, from the perspective of the public.

Setting: Australian public hospital system.

Participants: Adults (N=1994), reflecting the age and gender distribution of Queensland and South Australia.

Primary and secondary outcome measures: A discrete choice experiment in which respondents indicated which of two individuals with different characteristics should be prioritised for surgery in repeated hypothetical choices. Potential surgery recipients were described by seven key characteristics or attributes: body mass index (BMI), presence of comorbid conditions, age, family history, commitment to lifestyle change, time on the surgical wait list and chance of maintaining weight loss following surgery. A multinomial logit model was used to evaluate preferences and derive priority weights (primary analysis), with a latent class model used to explore respondent characteristics that were associated with variation in preference across the sample (see online supplementary analysis).

Results: A preference was observed to prioritise individuals who demonstrated a strong commitment to maintaining a healthy lifestyle as well as individuals categorised with very severe (BMI≥50 kg/m2) or (to a lesser extent) severe (BMI≥40 kg/m2) obesity, those who already have obesity-related comorbidity, with a family history of obesity, with a greater chance of maintaining weight loss or who had spent a longer time on the wait list. Lifestyle commitment was considered to be more than twice as important as any other criterion. There was little tendency to prioritise according to the age of the recipient. Respondent preferences were dependent on their BMI, previous experience with weight management surgery, current health state and education level.

Conclusions: This study extends our understanding of the publics' preferences for priority setting to the context of bariatric surgery, and derives priority weights that could be used to assist bodies responsible for commissioning bariatric services.

Keywords: HEALTH ECONOMICS; obesity.

Figure 1

Example choice set.

Figure 2

Priority weights for surgery according to criteria (from multinomial logit model model). Footnote to figure 2: Priority weights are relative to a score of zero for an individual who has obesity, is at risk of comorbid conditions rather than having developed them, has no family history, has not maintained a healthy lifestyle, has spent 6 months on the waiting list, and has a 30% chance of maintaining a substantial (at least 50%) reduction in excess weight. Priority points for time on wait list are per each month over 6 months and for change of maintaining weight loss are for each % over 30%.