Ahern et al. BMC Public Health 2011, 11:434 http://www.biomedcentral.com/1471-2458/11/434 partnership with the NHS and is an important first step towards building an evidence base for primary care referral to a commercial weight loss provider. In this pragmatic analysis, the findings are limited by the data available and its quality. Weight measurements were made and recorded by WW group leaders, and were not collected for the purpose of research. Data is only available from PCTs with existing procurement contracts with WW and these are not necessarily nationally representative. In addition data is only avail- able for those participants who ‘activated’ their WW packs and not those who received a referral but chose not to attend. However, it is a strength of this study that data was collected in routine care and reflects the weight loss achieved across the UK by all PCTs utilising the scheme. There are currently 67 PCTs and 1311 GPs actively referring patients to WW through their NHS Referral scheme, and 100 primary care organisations have utilised the scheme since 2005. This represents more than half the PCTs in the UK at the time. Conclusions The weight loss achieved through the WW NHS Refer- ral Scheme is comparable to other treatment options available in primary care. This intervention can be deliv- ered on a scale that exceeds the capacity of current pro- grammes led by NHS staff and at modest cost to the NHS. Referral to WW offers a useful first line weight- loss intervention for selected patients who are willing and able to join such groups. However, previous research has shown that in many cases the weight lost with behavioural interventions is regained after treat- ment cessation and future research should examine the long term outcomes of patients referred to WW through this scheme and evaluate this treatment in direct comparison to other treatment options. Authors’ contributions All authors contributed to the design and analysis of the study and to the drafting and revision of the final manuscript. The authors take full responsibility for the conduct of the research and the analyses and interpretation of the data. The research team had full access to the data and had the right to publish any and all data, separate and apart from the attitudes of the sponsor. Competing interests This data analysis presented here was funded by Weight Watchers through a grant to the Medical Research Council. None of the authors has benefitted personally from this research or received remuneration from Weight Watchers. All authors have completed the Unified Competing Interest form at http:// www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: financial support for the submitted work from Weight Watchers; SAJ receives a fee for nutrition articles, lectures and interviews from businesses linked to the Rosemary Conley organisation and the conclusions of this study may have implications for the company; no other relationships or activities that could appear to have influenced the submitted work. Page 5 of 5 Received: 15 December 2010 Accepted: 6 June 2011 Published: 6 June 2011 References 1. The NHS Information Centre Lifestyle Statistics: Statistics on obesity, physical activity and diet: England, February 2009. London: The Health and Social Care Information Centre; 2009. 2. Foresight: Tackling Obesities: Future Choices - Project Report. Government Office for Science; 2007. 3. McCormick B, Stone I: Economic costs of obesity and the case for government intervention. Obes Rev 2007, 8(Suppl 1):161-164. 4. NICE: Obesity: guidance on the prevention, identification, assessment and management of overweight and obesity in adults and children. London: National Institute for Health and Clinical Excellence; 2006. 5. Franz MJ, VanWormer JJ, Crain AL, Boucher JL, Histon T, Caplan W, Bowman JD, Pronk NP: Weight-loss outcomes: a systematic review and meta-analysis of weight-loss clinical trials with a minimum 1-year follow-up. Journal of the American Dietetic Association 2007, 107(10):1755-1767. 6. Unit CGO: Healthy Weight, Healthy Lives: a Cross-Government Strategy for England.Edited by: Department of Health and Department of Children SaF 2008. 7. Heshka S, Anderson JW, Atkinson RL, Greenway FL, Hill JO, Phinney SD, Kolotkin RL, Miller-Kovach K, Pi-Sunyer FX: Weight loss with self-help compared with a structured commercial program: a randomized trial. Jama 2003, 289(14):1792-1798. 8. Laws R: A new evidence-based model for weight management in primary care: the Counterweight Programme. J Hum Nutr Diet 2004, 17(3):191-208. 9. Truby H, Baic S, deLooy A, Fox KR, Livingstone MB, Logan CM, Macdonald IA, Morgan LM, Taylor MA, Millward DJ: Randomised controlled trial of four commercial weight loss programmes in the UK: initial findings from the BBC “diet trials”. BMJ (Clinical research ed) 2006, 332(7553):1309-1314. 10. Inelmen EM, Toffanello ED, Enzi G, Gasparini G, Miotto F, Sergi G, Busetto L: Predictors of drop-out in overweight and obese outpatients. International journal of obesity (2005) 2005, 29(1):122-128. 11. Dansinger ML, Tatsioni A, Wong JB, Chung M, Balk EM: Meta-analysis: the effect of dietary counseling for weight loss. Annals of internal medicine 2007, 147(1):41-50. 12. Cooper Z, Doll HA, Hawker DM, Byrne S, Bonner G, Eeley E, O’Connor ME, Fairburn CG: Testing a new cognitive behavioural treatment for obesity: A randomized controlled trial with three-year follow-up. Behaviour research and therapy 2010, 48(8):706-713. 13. Dale KS, Mann JI, McAuley KA, Williams SM, Farmer VL: Sustainability of lifestyle changes following an intensive lifestyle intervention in insulin resistant adults: Follow-up at 2-years. Asia Pacific journal of clinical nutrition 2009, 18(1):114-120. 14. Cobiac L, Vos T, Veerman L: Cost-effectiveness of Weight Watchers and the Lighten Up to a Healthy Lifestyle program. Australian and New Zealand journal of public health 2010, 34(3):240-247. 15. Nanchahal K, Townsend J, Letley L, Haslam D, Wellings K, Haines A: Weight- management interventions in primary care: a pilot randomised controlled trial. Br J Gen Pract 2009, 59(562):e157-166. 16. Lavin JH, Avery A, Whitehead SM, Rees E, Parsons J, Bagnall T, Barth JH, Ruxton CH: Feasibility and benefits of implementing a Slimming on Referral service in primary care using a commercial weight management partner. Public health 2006, 120(9):872-881. 17. Evaluation of the Counterweight Programme for obesity management in primary care: a starting point for continuous improvement. Br J Gen Pract 2008, 58(553):548-554. Pre-publication history The pre-publication history for this paper can be accessed here: http://www.biomedcentral.com/1471-2458/11/434/prepub doi:10.1186/1471-2458-11-434 Cite this article as: Ahern et al.: Weight Watchers on prescription: An observational study of weight change among adults referred to Weight Watchers by the NHS. BMC Public Health 2011 11:434.