title: Randomised controlled trial and economic analysis of an internet-based weight management programme: POWeR+ (Positive Online Weight Reduction).
abstract: Behavioural counselling with intensive follow-up for obesity is effective, but in resource-constrained primary care settings briefer approaches are needed.
  
  
  
  To estimate the clinical effectiveness and cost-effectiveness of an internet-based behavioural intervention with regular face-to-face or remote support in primary care, compared with brief advice.
  
  
  
  Individually randomised three-arm parallel trial with health economic evaluation and nested qualitative interviews.
  
  
  
  Primary care general practices in the UK.
  
  
  
  Patients with a body mass index of ≥ 30 kg/m2(or ≥ 28 kg/m2with risk factors) identified from general practice records, recruited by postal invitation.
  
  
  
  Positive Online Weight Reduction (POWeR+) is a 24-session, web-based weight management intervention completed over 6 months. Following online registration, the website randomly allocated participants using computer-generated random numbers to (1) the control intervention (n= 279), which had previously been demonstrated to be clinically effective (brief web-based information that minimised pressure to cut down foods, instead encouraging swaps to healthier choices and increasing fruit and vegetables, plus 6-monthly nurse weighing); (2) POWeR+F (n= 269), POWeR+ supplemented by face-to-face nurse support (up to seven contacts); or (3) POWeR+R (n= 270), POWeR+ supplemented by remote nurse support (up to five e-mails or brief telephone calls).
  
  
  
  The primary outcome was a modelled estimate of average weight reduction over 12 months, assessed blind to group where possible, using multiple imputation for missing data. The secondary outcome was the number of participants maintaining a 5% weight reduction at 12 months.
  
  
  
  A total of 818 eligible individuals were randomised using computer-generated random numbers. Weight change, averaged over 12 months, was documented in 666 out of 818 participants (81%; control,n= 227; POWeR+F,n= 221; POWeR+R,n= 218). The control group maintained nearly 3 kg of weight loss per person (mean weight per person: baseline, 104.4 kg; 6 months, 101.9 kg; 12 months, 101.7 kg). Compared with the control group, the estimated additional weight reduction with POWeR+F was 1.5 kg [95% confidence interval (CI) 0.6 to 2.4 kg;p= 0.001] and with POWeR+R was 1.3 kg (95% CI 0.34 to 2.2 kg;p= 0.007). By 12 months the mean weight loss was not statistically significantly different between groups, but 20.8% of control participants, 29.2% of POWeR+F participants (risk ratio 1.56, 95% CI 0.96 to 2.51;p= 0.070) and 32.4% of POWeR+R participants (risk ratio 1.82, 95% CI 1.31 to 2.74;p= 0.004) maintained a clinically significant 5% weight reduction. The POWeR+R group had fewer individuals who reported doing another activity to help lose weight [control, 47.1% (64/136); POWeR+F, 37.2% (51/137); POWeR+R, 26.7% (40/150)]. The incremental cost to the health service per kilogram weight lost, compared with the control group, was £18 (95% CI -£129 to £195) for POWeR+F and -£25 (95% CI -£268 to £157) for POWeR+R. The probability of being cost-effective at a threshold of £100 per kilogram was 88% and 98% for POWeR+F and POWeR+R, respectively. POWeR+R was dominant compared with the control group. No harms were reported and participants using POWeR+ felt more enabled in managing their weight. The qualitative studies documented that POWeR+ was viewed positively by patients and that health-care professionals generally enjoyed supporting patients using POWeR+.
  
  
  
  Maintenance of weight loss after 1 year is unknown.
  
  
  
  Identifying strategies for longer-term engagement, impact in community settings and increasing physical activity.
  
  
  
  Clinically valuable weight loss (> 5%) is maintained in 20% of individuals using novel written materials with brief follow-up. A web-based behavioural programme and brief support results in greater mean weight loss and 10% more participants maintain valuable weight loss; it achieves greater enablement and fewer participants undertaking other weight-loss activities; and it is likely to be cost-effective.
  
  
  
  Current Controlled Trials ISRCTN21244703.
  
  
  
  This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full inHealth Technology Assessment; Vol. 21, No. 4. See the NIHR Journals Library website for further project information.
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Little
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Beth
authors.initials: B
authors.lastname: Stuart
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
authors.forename: Fd Richard
authors.initials: FR
authors.lastname: Hobbs
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Jo
authors.initials: J
authors.lastname: Kelly
authors.affiliation: Centre for Applications of Health Psychology (CAHP), Faculty of Social and Human Sciences, University of Southampton, Southampton, UK.
authors.forename: Emily R
authors.initials: ER
authors.lastname: Smith
authors.affiliation: Centre for Applications of Health Psychology (CAHP), Faculty of Social and Human Sciences, University of Southampton, Southampton, UK.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Bradbury
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Hughes
authors.affiliation: Southampton Statistical Sciences Research Institute, University of Southampton, Southampton, UK.
authors.forename: Peter Wf
authors.initials: PW
authors.lastname: Smith
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Moore
authors.affiliation: Human Nutrition, School of Medicine, University of Glasgow, Glasgow, UK.
authors.forename: Mike Ej
authors.initials: ME
authors.lastname: Lean
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Barrie M
authors.initials: BM
authors.lastname: Margetts
authors.affiliation: National Institute for Health Research (NIHR) Southampton Biomedical Research Centre, University Hospital Southampton, Southampton, UK.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Byrne
authors.affiliation: Medical Research Council (MRC) Epidemiology Unit, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus, Cambridge, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Griffin
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
authors.forename: Mina
authors.initials: M
authors.lastname: Davoudianfar
authors.affiliation: Primary Care and Population Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Hooper
authors.affiliation: Health Economic Analyses Team (HEAT), Primary Care and Population Sciences Unit, University of Southampton, Southampton, UK.
authors.forename: Guiqing
authors.initials: G
authors.lastname: Yao
authors.affiliation: Health Economic Analyses Team (HEAT), Primary Care and Population Sciences Unit, University of Southampton, Southampton, UK.
authors.forename: Shihua
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Health Economic Analyses Team (HEAT), Primary Care and Population Sciences Unit, University of Southampton, Southampton, UK.
authors.forename: James
authors.initials: J
authors.lastname: Raftery
authors.affiliation: Centre for Applications of Health Psychology (CAHP), Faculty of Social and Human Sciences, University of Southampton, Southampton, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Yardley
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose; D001794:Blood Pressure; D015992:Body Mass Index; D003362:Cost-Benefit Analysis; D000072001:Diet, Healthy; D015444:Exercise; D005260:Female; D006801:Humans; D020407:Internet; D008055:Lipids / Q000097:blood; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000628:therapy*; D011320:Primary Health Care / Q000379:methods*; D019057:Quality-Adjusted Life Years; D016037:Single-Blind Method; D013222:State Medicine / Q000191:economics; D006113:United Kingdom; D015431:Weight Loss; D061217:Weight Reduction Programs / Q000191:economics* / Q000379:methods*
chemical_list: D001786:Blood Glucose; D008055:Lipids