The equity impact of brief opportunistic interventions to promote weight loss in primary care: secondary analysis of the BWeL randomised trial

Abstract

Background Guidelines recommend that clinicians should make brief opportunistic behavioural interventions to patients who are obese to increase the uptake of effective weight loss programmes. The objective was to assess the effect of this policy on socioeconomic equity. Methods One thousand eight hundred eighty-two consecutively attending patients with obesity and who were not seeking support for weight loss from their GP were enrolled in a trial. Towards the end of each consultation, GPs randomly assigned participants to one of two 30-s interventions. In the active intervention (support arm), the GP offered referral to a weight management group. In the control intervention (advice arm), the GP advised the patient that their health would benefit from weight loss. Agreement to attend a behavioural weight loss programme, attendance at the programme and weight loss at 12 months were analysed by socioeconomic status, measured by postcode using the Index of Multiple Deprivation (IMD). Results Mean weight loss was 2.43 kg (sd 6.49) in the support group and 1.04 kg (sd 5.50) for the advice only group, but these effects were moderated by IMD ( p = 0.039 for the interaction). In the support arm, weight loss was greater in higher socioeconomic groups. Participants from lower socioeconomic backgrounds were more likely to accept the offer and equally likely to attend a weight loss referral but attended fewer sessions. Adjusting for these sequentially reduced the gradient for the association of socioeconomic status with weight loss from + 0.035 to − 0.001 kg/IMD point. In the advice only arm, 10% took effective action to promote weight loss. The decision to seek support for weight loss outside of the trial did not differ by socioeconomic status, but weight loss among deprived participants who used external support was greater than among more affluent participants ( p = 0.025). Conclusion Participants’ responses to GPs’ brief opportunistic interventions to promote weight loss differed by socioeconomic status and trial arm. In the support arm, more deprived people lost less weight because they attended fewer sessions at the programme. In the advice arm, more deprived people who sought and paid for support for weight loss themselves lost more weight than more affluent people who sought support. Trial registration This trial is registered with the ISRCTN registry, number ISRCTN26563137 . Date of registration: January 3, 2013; date of first participant recruited: June 4, 2014 Electronic supplementary material The online version of this article (10.1186/s12916-019-1284-y) contains supplementary material, which is available to authorized users.

Early Outcomes From the English National Health Service Diabetes Prevention Programme

“…People from more deprived areas were less likely to complete the program, lost less weight, and had smaller reductions in HbA 1c . Similarly, the Brief Interventions for Weight Loss trial found that participants from lower socioeconomic backgrounds attended fewer sessions, leading to less weight loss (25).…”

Brief interventions for obesity when patients are asked to pay for weight loss treatment: an observational study in primary care with an embedded randomised trial

“…Embedding a randomised trial allowed testing of two different ways of framing the cost of the weight loss programme. A limitation to the comparison of the two trials is that the population enrolled in the current study (BWeL-B) were in areas of greater deprivation and included a greater proportion of patients from ethnic minority groups compared with BWeL; however, in BWeL there was no association between deprivation score or ethnicity and the likelihood of patients attending the programme, 1,12 suggesting that these factors are unlikely to account for such large differences in uptake of the programme.…”

A systematic review examining socioeconomic factors in trials of interventions for men that report weight as an outcome

“…Inequalities can occur at any stage of trials (i.e., during recruitment, adherence, or outcomes) of weight management programs 106 . For example, in a large RCT of brief opportunistic primary care interventions, participants from lower socioeconomic backgrounds that were assigned to the behavioral weight management program referral group, on average, lost less weight than their counterparts from higher socioeconomic backgrounds 107 . This was attributed to those from lower socioeconomic backgrounds attending fewer program sessions (i.e., inequalities related to intervention adherence) 107 .…”

“… 106 For example, in a large RCT of brief opportunistic primary care interventions, participants from lower socioeconomic backgrounds that were assigned to the behavioral weight management program referral group, on average, lost less weight than their counterparts from higher socioeconomic backgrounds. 107 This was attributed to those from lower socioeconomic backgrounds attending fewer program sessions (i.e., inequalities related to intervention adherence). 107 Differential effectiveness was only examined in one of the studies included in this review, the FFIT trial.…”

“… 107 This was attributed to those from lower socioeconomic backgrounds attending fewer program sessions (i.e., inequalities related to intervention adherence). 107 Differential effectiveness was only examined in one of the studies included in this review, the FFIT trial. 98 In pre‐specified subgroup analysis, no significant predictors of the interventions effect on weight (the primary outcome) were observed, including for education level, area disadvantage, and employment status.…”