The clinical effectiveness and cost-effectiveness of long-term weight management schemes for adults: a systematic review.

OBJECTIVE: To assess the long-term clinical effectiveness and cost-effectiveness of multicomponent weight management schemes for adults in terms of weight loss and maintenance of weight loss.

DATA SOURCES: Bibliographic databases were searched from inception to December 2009, including the Cochrane Library, MEDLINE (Ovid), EMBASE (Ovid), and MEDLINE In-Process & Other Non-Indexed Citations. Bibliographies of related papers were screened, key conferences and symposia were searched and experts were contacted to identify additional published and unpublished references.

REVIEW METHODS: For the clinical effectiveness review, two reviewers independently screened titles and abstracts for eligibility. Inclusion criteria were applied to the full text of retrieved papers by one reviewer and checked by a second reviewer using a pre-piloted inclusion flow chart. The studies were long-term randomised controlled trials (RCTs) of adult participants who were classified by body mass index as overweight or obese. Interventions were multicomponent weight management programmes (including diet, physical activity and behaviour change strategies) that assessed weight measures. Programmes that involved the use of over-the-counter medicines licensed in the UK were also eligible. For the cost-effectiveness review two reviewers independently screened studies for inclusion. Cost-effectiveness, cost-utility, cost-benefit or cost-consequence analyses were eligible. Data were extracted using a standardised and pre-piloted data extraction form. The quality of included studies was assessed using standard criteria. Studies were synthesised through a narrative review with full tabulation of results.

RESULTS: A total of 3358 references were identified, of which 12 were included in the clinical effectiveness review. Five RCTs compared multicomponent interventions with non-active comparator groups. In general, weight loss appeared to be greater in the intervention groups than in the comparator groups. Two RCTs compared multicomponent interventions that focused on the diet component. In these studies there were no statistically significant differences in weight loss between interventions. Four RCTs compared multicomponent interventions that focused on the physical activity component. There was little consistency in the pattern of results seen, in part owing to the differences in the interventions. In one RCT the intervention focused on the goal-setting interval and it appeared that weight loss was greatest in those given daily goals compared with weekly goals. Overall, where measured, it appeared that most groups began to regain weight at further follow-up. Of the 419 studies identified in the cost-effectiveness searches, none met the full inclusion criteria. Two economic evaluations are described in our review; however, caution is required in their interpretation, as they did not meet all inclusion criteria. Lifetime chronic disease models were used in these studies and the models included the costs and benefits of avoiding chronic illness. Both studies found the interventions to be cost-effective, with estimates varying between -£473 and £7200 (US$12,640) per quality-adjusted life-year gained; methodological omissions from these studies were apparent and caution is therefore required in the interpretation of these results.

CONCLUSIONS: Long-term multicomponent weight management interventions were generally shown to promote weight loss in overweight or obese adults. Weight changes were small however and weight regain was common. There were few similarities between the included studies; consequently an overall interpretation of the results was difficult to make. There is some evidence that weight management interventions are likely to be cost-effective, although caution is required as there were some limitations in the two cost-evaluation studies described.

FUNDING: The National Institute for Health Research Health Technology Assessment programme.