Screening and brief intervention for obesity in primary care: cost-effectiveness analysis in the BWeL trial

Research output: Contribution to journalArticlepeer-review


  • Lise Retat
  • Laura Pimpin
  • Laura Webber
  • Abbygail Jaccard
  • Amanda Lewis
  • Sarah Tearne
  • Kathryn Hood
  • Anna Christian-Brown
  • Rachna Begh
  • Alecia Nickless
  • Ly-Mee Yu
  • Susan Jebb
  • Paul Aveyard

Colleges, School and Institutes

External organisations

  • University of Bristol
  • University of Oxford


The Brief Intervention for Weight Loss Trial enrolled 1882 consecutively attending primary care patients who were obese and participants were randomised to physicians opportunistically endorsing, offering, and facilitating a referral to a weight loss programme (support) or recommending weight loss (advice). After one year, the support group lost 1.4kg more (95%CI 0.9 to 2.0): 2.4 kg versus 1.0 kg. We use a cohort simulation to predict effects on disease incidence, quality of life, and healthcare costs over 20 years.

Randomly sampling from the trial population, we created a virtual cohort of 20 million adults and assigned baseline morbidity. We applied the weight loss observed in the trial and assumed weight regain over four years. Using epidemiological data, we assigned the incidence of 12 weight-related diseases depending on baseline disease status, age, gender, body mass index. From a healthcare perspective, we calculated the quality adjusted life years (QALYs) accruing and calculated the incremental difference between trial arms in costs expended in delivering the intervention and healthcare costs accruing. We discounted future costs and benefits at 1.5% over 20 years.

Compared with advice, the support intervention reduced the cumulative incidence of weight-related disease by 722/100,000 people, 0.33% of all weight-related disease. The incremental cost of support over advice was £2.01million/100,000. However, the support intervention reduced health service costs by £5.86 million/100,000 leading to a net saving of £3.85 million/100,000. The support intervention produced 992 QALYs/100,000 people relative to advice.

A brief intervention in which physicians opportunistically endorse, offer, and facilitate a referral to a behavioural weight management service to patients with a BMI of at least 30kg/m2 reduces healthcare costs and improves health more than advising weight loss.


Original languageEnglish
Pages (from-to)2066-2075
Number of pages10
JournalInternational Journal of Obesity
Issue number10
Early online date31 Jan 2019
Publication statusPublished - Oct 2019