Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Rigorous control conditions diminish treatment effects in weight loss-randomized controlled trials.

ABSTRACT:

Background

It has not been established whether control conditions with large weight losses (WLs) diminish expected treatment effects in WL or prevention of weight gain (PWG)-randomized controlled trials (RCTs).

Subjects/methods

We performed a meta-analysis of 239 WL/PWG RCTs that include a control group and at least one treatment group. A maximum likelihood meta-analysis framework was used to model and understand the relationship between treatment effects and control group outcomes.

Results

Under the informed model, an increase in control group WL of 1 kg corresponds with an expected shrinkage of the treatment effect by 0.309 kg (95% confidence interval (-0.480, -0.138), P=0.00081); this result is robust against violations of the model assumptions.

Conclusions

We find that control conditions with large WLs diminish expected treatment effects. Our investigation may be helpful to clinicians as they design future WL/PWG studies.

SUBMITTER: Dawson JA

PROVIDER: S-EPMC4826650 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Rigorous control conditions diminish treatment effects in weight loss-randomized controlled trials.

Dawson J A JA Kaiser K A KA Affuso O O Cutter G R GR Allison D B DB

International journal of obesity (2005) 20151009 6

<h4>Background</h4>It has not been established whether control conditions with large weight losses (WLs) diminish expected treatment effects in WL or prevention of weight gain (PWG)-randomized controlled trials (RCTs).<h4>Subjects/methods</h4>We performed a meta-analysis of 239 WL/PWG RCTs that include a control group and at least one treatment group. A maximum likelihood meta-analysis framework was used to model and understand the relationship between treatment effects and control group outcome ...[more]

PMID: 26449419

Similar Datasets

Weight change among people randomized to minimal intervention control groups in weight loss trials.

Project description:Evidence on the effectiveness of behavioral weight management programs often comes from uncontrolled program evaluations. These frequently make the assumption that, without intervention, people will gain weight. The aim of this study was to use data from minimal intervention control groups in randomized controlled trials to examine the evidence for this assumption and the effect of frequency of weighing on weight change.Data were extracted from minimal intervention control arms in a systematic review of multicomponent behavioral weight management programs. Two reviewers classified control arms into three categories based on intensity of minimal intervention and calculated 12-month mean weight change using baseline observation carried forward. Meta-regression was conducted in STATA v12.Thirty studies met the inclusion criteria, twenty-nine of which had usable data, representing 5,963 participants allocated to control arms. Control arms were categorized according to intensity, as offering leaflets only, a single session of advice, or more than one session of advice from someone without specialist skills in supporting weight loss. Mean weight change at 12 months across all categories was -0.8 kg (95% CI -1.1 to -0.4). In an unadjusted model, increasing intensity by moving up a category was associated with an additional weight loss of -0.53 kg (95% CI -0.96 to -0.09). Also in an unadjusted model, each additional weigh-in was associated with a weight change of -0.42 kg (95% CI -0.81 to -0.03). However, when both variables were placed in the same model, neither intervention category nor number of weigh-ins was associated with weight change.Uncontrolled evaluations of weight loss programs should assume that, in the absence of intervention, their population would weigh up to a kilogram on average less than baseline at the end of the first year of follow-up.

| S-EPMC4820081 | biostudies-other

Weight Loss Randomized Intervention Trials in Female Cancer Survivors.

Project description:Purpose Observational study evidence has associated overweight/obesity with decreased survival in women with breast cancer and with several other cancers. Although full-scale, definitive weight loss adjuvant intervention trials with cancer end points remain to be conducted, a number of randomized controlled trials have evaluated weight loss interventions in survivors of cancer in women. Findings from these trials in breast, endometrial, and ovarian cancer are reviewed. Methods A systematic review of randomized controlled clinical trials evaluating weight loss interventions was updated (for studies published 2013 to 2016), and clinical trials registers were searched for ongoing trials. Results Six new randomized trials in breast cancer survivors and two randomized trials in endometrial cancer survivors were identified. Evidence from these trials and the 10 earlier randomized trials in female cancer survivors provide support for the feasibility of recruiting women closer to the cancer diagnosis and efficacy for achieving weight loss, in particular with telephone-based interventions, and have identified the challenge of achieving significant weight loss in African American cancer survivors and of maintaining weight loss in any cancer survivor group. Seven ongoing randomized trials are evaluating the influence of weight loss interventions on cancer end points (five in breast cancer, one in ovarian cancer, and one in endometrial cancer). Conclusion After a decade of preliminary studies, ongoing randomized, controlled clinical trials will potentially provide definitive assessment of whether weight loss can improve breast cancer clinical outcome. Longer-term interventions (> 2 years' duration) may be needed to optimize weight loss maintenance and any potential benefits on cancer end points.

| S-EPMC5455319 | biostudies-other

Data integration for prediction of weight loss in randomized controlled dietary trials.

Project description:Diet is an important component in weight management strategies, but heterogeneous responses to the same diet make it difficult to foresee individual weight-loss outcomes. Omics-based technologies now allow for analysis of multiple factors for weight loss prediction at the individual level. Here, we classify weight loss responders (N = 106) and non-responders (N = 97) of overweight non-diabetic middle-aged Danes to two earlier reported dietary trials over 8 weeks. Random forest models integrated gut microbiome, host genetics, urine metabolome, measures of physiology and anthropometrics measured prior to any dietary intervention to identify individual predisposing features of weight loss in combination with diet. The most predictive models for weight loss included features of diet, gut bacterial species and urine metabolites (ROC-AUC: 0.84-0.88) compared to a diet-only model (ROC-AUC: 0.62). A model ensemble integrating multi-omics identified 64% of the non-responders with 80% confidence. Such models will be useful to assist in selecting appropriate weight management strategies, as individual predisposition to diet response varies.

| S-EPMC7674420 | biostudies-literature

Association of run-in periods with weight loss in obesity randomized controlled trials.

Project description:Study-level design characteristics that inform the optimal design of obesity randomized controlled trials (RCTs) have been examined in few studies. A pre-randomization run-in period is one such design element that may influence weight loss. We examined 311 obesity RCTs published between 1 January 2007 and 1 July 2009 that examine d weight loss or weight gain prevention as a primary or secondary end-point. Variables included run-in period, pre-post intervention weight loss, study duration (time), intervention type, percent female and degree of obesity. Linear regression was used to estimate weight loss as a function of (i) run-in (yes/no) and (ii) run-in, time, percent female, body mass index and intervention type. Interaction terms were also examined. Approximately 19% (18.6%) of the studies included a run-in period, with pharmaceutical studies having the highest frequency. Although all intervention types were associated with weight loss (Mean = 2.80 kg, SD = 3.52), the inclusion of a pre-randomization run-in was associated with less weight loss (P = 0.0017) compared with studies that did not include a run-in period. However, this association was not consistent across intervention types. Our results imply that in trials primarily targeting weight loss in adults, run-in periods may not be beneficial for improving weight loss outcomes in interventions.

| S-EPMC3885242 | biostudies-literature

Commercial Programs' Online Weight-Loss Claims Compared to Results from Randomized Controlled Trials.

Project description:ObjectiveTo characterize weight-loss claims and disclaimers present on websites for commercial weight-loss programs and compare them with results from published randomized controlled trials (RCTs).MethodsA content analysis of all home pages and testimonials available on the websites of 24 randomly selected programs was performed. Two team members independently reviewed each page and abstracted information from text and images to capture relevant content, including demographics, weight loss, and disclaimers. A systematic review was performed to evaluate the efficacy of these programs by searching MEDLINE and the Cochrane Database of Systematic Reviews, and the mean weight change from each RCT included was abstracted.ResultsOverall, the amount of weight loss portrayed in the testimonials was extreme across all programs examined (range median weight loss 10.7-49.5 kg). Only 10 out of the 24 programs had eligible RCTs. Median weight losses reported in testimonials exceeded that achieved by trial participants. Most programs with RCTs (78%) provided disclaimers stating that the testimonial's results were nontypical and/or gave a range of typical weight loss.ConclusionsWeight-loss claims within testimonials were higher than results from RCTs. Future studies should examine whether commercial programs' advertising practices influence patients' expectations or satisfaction with modest weight-loss results.

| S-EPMC5678966 | biostudies-literature

Can attention control conditions have detrimental effects on behavioral medicine randomized trials?

Project description:ObjectiveAttention control (AC) conditions are used to balance nonspecific attention in randomized trials of behavioral interventions. Very little guidance about which behavioral interventions and outcomes merit AC is available in the literature. The primary aim of the present study is to demonstrate a scenario in which use of AC in a behavioral randomized trial was unnecessary and possibly detrimental.MethodsExploratory analyses were performed in a randomized controlled trial that tested whether a patient-centered counseling intervention reduced low-density lipoprotein cholesterol levels in 355 participants with peripheral arterial disease, compared with AC and usual care (UC) conditions. The patient-centered counseling intervention was designed to activate participants to ask their physician for lipid-lowering medication and/or increase dose intensity, increase medication adherence, and reduce fat intake. The AC condition involved attention-matched telephone-delivered health education, and the UC condition consisted of an educational pamphlet.ResultsAt 12-month follow-up, the mean low-density lipoprotein cholesterol changes were -11.1 and -6.8 mg/dL in the UC and AC conditions, respectively (p=.17). The proportion of participants who increased the use or dose intensity of medication was significantly lower in AC than in UC: 17.5% versus 30.5% (p=.03). No significant difference in other outcomes was observed between AC and UC.ConclusionsAC has significantly worse medication outcomes, and there is no indication of a therapeutic effect on other end points. Implications for the use of AC in behavioral randomized trials are discussed.Trial registrationclinicaltrials.gov Identifier: NCT00217919.

| S-EPMC3570637 | biostudies-literature

Randomized controlled trial testing the effects of weight loss on nonalcoholic steatohepatitis.

Project description:Nonalcoholic steatohepatitis (NASH) is a chronic progressive liver disease that is strongly associated with obesity. Currently, there is no approved therapy for NASH. Weight reduction is typically recommended, but efficacy data are lacking. We performed a randomized controlled trial to examine the effects of lifestyle intervention using a combination of diet, exercise, and behavior modification, with a goal of 7% to 10% weight reduction, on clinical parameters of NASH. The primary outcome measure was the change in NASH histological activity score (NAS) after 48 weeks of intervention. Thirty-one overweight or obese individuals (body mass index [BMI], 25-40 kg/m(2)) with biopsy-proven NASH were randomized in a 2:1 ratio to receive intensive lifestyle intervention (LS) or structured education (control). After 48 weeks of intervention, participants assigned to LS lost an average of 9.3% of their weight versus 0.2% in the control group (P = 0.003). A higher proportion of participants in the LS group had a reduction of NAS of at least 3 points or had posttreatment NAS of 2 or less as compared with the control group (72% versus 30%, P = 0.03). NAS improved significantly in the LS group (from 4.4 to 2.0) in comparison with the control group (from 4.9 to 3.5) (P = 0.05). Percent weight reduction correlated significantly with improvement in NAS (r = 0.497, P = 0.007). Participants who achieved the study weight loss goal (>or=7%), compared with those who lost less than 7%, had significant improvements in steatosis (-1.36 versus -0.41, P < 0.001), lobular inflammation (-0.82 versus -0.24, P = 0.03), ballooning injury (-1.27 versus -0.53, P = 0.03) and NAS (-3.45 versus -1.18, P < 0.001).Weight reduction achieved through lifestyle intervention leads to improvements in liver histology in NASH.

| S-EPMC2799538 | biostudies-literature

What matters for weight loss in behavioral trials in the Latinx community: Learnings from three randomized controlled trials.

Project description:BackgroundNearly half of Latinx adults in the US are obese, making effective weight loss interventions crucial to prevent associated chronic conditions.ObjectiveTo identify factors associated with increased session attendance and clinically significant weight loss among Latinx adults.ParticipantsLatinx participants from the Vivamos Activos (n = 207), Vida Sana (n = 191), and HOMBRE (n = 424 Latinx men) randomized clinical trials.DesignPost-hoc analysis of randomized controlled trial data.InterventionCulturally-adapted behavioral weight loss interventions based on the Diabetes Prevention Program among Latinx adults over 12 months.Main outcome measureDemographic, clinical, and psychosocial predictors of session attendance and 5% weight loss at 12-months.Statistical analysis performedBi-variable associations between baseline characteristics and outcomes were tested with chi-square and t-tests. Those with p-value< 0.15 were then included in stepwise logistic regressions.ResultsParticipants (N = 822) were middle age with diverse socioeconomic backgrounds. Older age in the Vivamos Activos and Vida Sana trials, and lower acculturation in the HOMBRE trial were significant predictors of increased session attendance. Factors associated with 5% weight loss varied by trials. These included younger age (OR 0.96 95% CI 0.92, 0.99) in Vivamos Activos, higher acculturation (OR 1.88 95% CI 1.05, 3.37) in Vida Sana, and higher education (OR 3.20 95% CI 1.3, 7.03) and greater body image dissatisfaction (OR 1.29, 95% CI 1.04, 1.6), and lower acculturation (0.69 95% CI 0.5, 0.96) in HOMBRE.ConclusionsFew and conflicting baseline characteristics were associated with session attendance and clinically significant weight loss, suggesting that alternative approaches to optimizing interventions are needed.

| S-EPMC10810045 | biostudies-literature

Randomized controlled trial of financial incentives during weight-loss induction and maintenance in online group weight control.

Project description:ObjectiveThis study examined the impact of a financial incentive scheme integrating process and outcome incentives across weight-loss induction and weight maintenance on 18-month weight outcomes.MethodsThis was a randomized controlled trial. Participants with overweight or obesity (n = 418; 91% female; 28% racial/ethnic minority) were randomized to an 18-month, online, group-based behavioral weight-control program (Internet-Only) or the same program with financial incentives provided for 12 months, contingent on self-regulatory weight-control behaviors (self-weighing, dietary self-monitoring, and physical activity) and weight-outcome benchmarks (Internet+Incentives). No financial incentives were provided from Months 13 to 18 to examine the durability of weight-control behaviors and outcomes without incentives.ResultsWeight-loss induction at Month 6 was significantly greater for Internet+Incentives than Internet-Only (6.8% vs. 4.9%, respectively, p = 0.01). Individuals receiving incentives were significantly more likely to maintain weight loss ≥ 5% at Month 12 (45% in Internet+Incentives vs. 32% in Internet-Only, p < 0.02) and remain weight stable (39% vs. 27%, respectively, p < 0.01). Internet+Incentives participants also reported significantly greater behavioral engagement through Month 12. However, once incentives ceased, there were no differences in sustained weight outcomes (Month 18), and engagement declined dramatically.ConclusionsDespite promoting greater treatment engagement and initial weight loss, financial incentives as offered in this study did not promote better extended weight control.

| S-EPMC10519100 | biostudies-literature

Effects of Ephedrine-Containing Products on Weight Loss and Lipid Profiles: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Project description:Ephedrine, the main active ingredient of mahuang, may lead to weight loss; however, it can also induce cardiovascular side effects. As ephedrine use remains controversial, this study aimed to systematically review previous studies on ephedrine-containing products and perform meta-analysis of the existing evidence on weight, blood pressure (BP), heart rate, and lipid change effects of ephedrine-containing products. We searched for placebo-controlled randomized studies in PubMed, Web of Science, and EMBASE until July 2021 using the following search terms: (ephedr* OR mahuang) AND ("weight loss" OR obes* OR overweight). Mean differences (MDs) and 95% confidence intervals (CIs) were calculated to evaluate the effects of ephedrine-containing products on weight, BP, heart rate, and lipid profiles. A total of 10 articles were included. Compared with the placebo group, the ephedrine-containing product group was associated with greater weight loss, with an MD of -1.97 kg (95% CI: -2.38, -1.57). In the ephedrine-containing product group, the mean heart rate was 5.76 beats/min higher than in the placebo group (95% CI: 3.42, 8.10), whereas intergroup differences in systolic and diastolic BP were not statistically significant. The ephedrine-containing product group had a significantly higher mean high-density lipoprotein cholesterol level (MD: 2.74 mg/dL; 95% CI: 0.94, 4.55), lower mean low-density lipoprotein cholesterol level (MD: -5.98 mg/dL; 95% CI: -10.97, -0.99), and lower mean triglyceride level (MD: -11.25 mg/dL; 95% CI: -21.83, -0.68) than the placebo group. Compared with placebo, the ephedrine-containing products showed better effects on weight loss and lipid profiles, whereas they caused increased heart rate. The ephedrine-containing products may be beneficial to obese or overweight patients; however, close monitoring is needed, especially heart rate monitoring.

| S-EPMC8618781 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data