TY - JOUR
T1 - The challenge of a 2-year follow-up after intervention for weight loss in primary care
AU - Holzapfel, C.
AU - Cresswell, L.
AU - Ahern, A. L.
AU - Fuller, N. R.
AU - Eberhard, M.
AU - Stoll, J.
AU - Mander, A. P.
AU - Jebb, S. A.
AU - Caterson, I. D.
AU - Hauner, H.
N1 - Funding Information:
We thank participants and the staff of participating primary care practices for their contribution to the trial. The authors had full access to all the data in the study, and the corresponding author had the final responsibility for the decision to submit for publication. Weight Watchers International, through a grant to the UK Medical Research Council. The CP intervention was delivered by an employee of the sponsor, but the sponsor had no role in the study design, data collection, data analysis, data interpretation or writing of the report.
Funding Information:
All authors declare financial support to their institutions for the submitted work from Weight Watchers. LC has received payment from LighterLife Ltd. for consultancy services. SAJ has received research grants for other clinical trials from Sanofi-Aventis and Coca Cola. IDC and NRF have received research grants for other clinical trials funded by Sanofi-Aventis, Allergan, Roche Products, MSD, Novo Nordisk and GlaxoSmithKline. NRF has received conference travel expenses from Allergan. HH has received a travel grant from Roche. SAJ is a member of the Tanita Medical Advisory Board and has received payment for nutrition articles and lectures for Rosemary Conley Enterprises. HH is on the Advisory Board for Weight Watchers International and has received payment for lectures from Sara Lee, Lilly, Novartis, Sanofi-Aventis and Bristol-Myers Squibb. IDC was a board member for the SCOUT trial and has received payment for lectures from iNova Pharmaceuticals, Eisai Pharmaceuticals, Pfizer Australia and Servier Laboratories (Australia).
PY - 2014/6
Y1 - 2014/6
N2 - Background: Many weight loss programmes show short-term success, but long-term data in larger studies are scarce, especially in community settings. Attrition is common and complicates the interpretation of long-term outcomes. Objective: To investigate 2-year outcomes and explore issues of attrition and missing data. Subjects: A total of 772 overweight and obese adults recruited by primary care practices in Australia, Germany and the UK and randomised to a 12-month weight loss intervention delivered in a commercial programme (CP) or in standard care (SC).Measurement: Weight change from 0-24 and 12-24 months including measured weights only and measured and self-reported weights, using last observation carried forward (LOCF), baseline observation carried forward (BOCF), completers-only and missing-at-random (MAR) analyses. Results: A total of 203 participants completed the 24-month visit. Using measured weights only, there was a trend for greater 24-month weight loss in CP than in SC, but the difference was only statistically significant in the LOCF and BOCF analyses: LOCF: -4.14 vs -1.99 kg, difference adjusted for centre -2.08 kg, P<0.001; BOCF: -1.33 vs -0.74 kg, adjusted difference -0.60 kg, P=0.032; completers: -4.76 vs -2.99 kg, adjusted difference -1.53 kg, P=0.113; missing at random: -3.00 vs -1.94 kg, adjusted difference -1.04 kg, P=0.150. Both groups gained weight from 12-24 months and weight regain was significantly (P<0.001) greater for CP than for SC in all analysis approaches. Inclusion of self-reported weights from a further 138 participants did not change the interpretation of the findings. Conclusion: Initial weight loss was poorly maintained during the no-intervention follow-up, but both groups did have lower weight over the 24 months. Attrition was high in both groups, and assumptions about missing data had considerable impact on the magnitude and statistical significance of treatment effects. It is vital that trials on weight loss interventions consider the plausibility of these differences in an analytical approach when interpreting research findings and comparing data between studies.
AB - Background: Many weight loss programmes show short-term success, but long-term data in larger studies are scarce, especially in community settings. Attrition is common and complicates the interpretation of long-term outcomes. Objective: To investigate 2-year outcomes and explore issues of attrition and missing data. Subjects: A total of 772 overweight and obese adults recruited by primary care practices in Australia, Germany and the UK and randomised to a 12-month weight loss intervention delivered in a commercial programme (CP) or in standard care (SC).Measurement: Weight change from 0-24 and 12-24 months including measured weights only and measured and self-reported weights, using last observation carried forward (LOCF), baseline observation carried forward (BOCF), completers-only and missing-at-random (MAR) analyses. Results: A total of 203 participants completed the 24-month visit. Using measured weights only, there was a trend for greater 24-month weight loss in CP than in SC, but the difference was only statistically significant in the LOCF and BOCF analyses: LOCF: -4.14 vs -1.99 kg, difference adjusted for centre -2.08 kg, P<0.001; BOCF: -1.33 vs -0.74 kg, adjusted difference -0.60 kg, P=0.032; completers: -4.76 vs -2.99 kg, adjusted difference -1.53 kg, P=0.113; missing at random: -3.00 vs -1.94 kg, adjusted difference -1.04 kg, P=0.150. Both groups gained weight from 12-24 months and weight regain was significantly (P<0.001) greater for CP than for SC in all analysis approaches. Inclusion of self-reported weights from a further 138 participants did not change the interpretation of the findings. Conclusion: Initial weight loss was poorly maintained during the no-intervention follow-up, but both groups did have lower weight over the 24 months. Attrition was high in both groups, and assumptions about missing data had considerable impact on the magnitude and statistical significance of treatment effects. It is vital that trials on weight loss interventions consider the plausibility of these differences in an analytical approach when interpreting research findings and comparing data between studies.
KW - primary care
KW - weight loss
KW - weight maintenance
UR - http://www.scopus.com/inward/record.url?scp=84902247490&partnerID=8YFLogxK
U2 - 10.1038/ijo.2013.180
DO - 10.1038/ijo.2013.180
M3 - Article
C2 - 24030517
AN - SCOPUS:84902247490
SN - 0307-0565
VL - 38
SP - 806
EP - 811
JO - International Journal of Obesity
JF - International Journal of Obesity
IS - 6
ER -
