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

Considerations for the design and conduct of pediatric obesity pharmacotherapy clinical trials: Proceedings of expert roundtable meetings

Anti-obesity medications (AOMs) have emerged as one element of comprehensive obesity clinical care intended to improve long-term health outcomes for children and adolescents. The number of pediatric AOM clinical trials has burgeoned in recent years as new pharmacotherapeutics have been developed. Factors related to growth and development in children and adolescents can present unique challenges in terms of designing and conducting clinical trials investigating the safety and efficacy of AOMs. These barriers can delay the AOM development and evaluation process, increase the cost of performing trials, create challenges in the interpretation of results, influence the generalizability of the findings and present ethical dilemmas. In an effort to address these issues and provide guidance to streamline the process of designing and conducting pediatric AOM clinical trials, relevant key stakeholders convened a series of roundtable meetings to discuss, debate and achieve harmonization on design features. Stakeholder participants included a multidisciplinary group of international pediatric obesity experts, patient (parent) representatives and representatives from academic medicine, key regulatory agencies and industry. Topics of discussion included primary efficacy end-points, secondary end-points, eligibility criteria, trial run-in and follow-up phases, use of active comparators and guidelines for down-titration and/or stopping rules for excessive weight reduction. Consensus recommendations were agreed upon. Regarding end-points, emphasis was placed on moving away from BMI z-score as a primary outcome, incorporating multiple alternative BMI-related outcomes and measuring adiposity/body fat as a prominent secondary end-point. Trial eligibility criteria were carefully considered to maximize generalizability while maintaining safety. The limited value of trial run-in phases was discussed. It was also underscored that designing trials with extended follow-up periods after AOM withdrawal should be avoided owing to ethical issues (including possible psychological harm) related to weight regain without providing the opportunity to access other treatments. The panel emphasized the value of the randomized, placebo-controlled trial but recommended the thoughtful consideration of the use of active comparators in addition to, or instead of, placebo to achieve clinical equipoise when appropriate. Finally, the panel recommended that clinical trial protocols should include clear guidance regarding AOM down-titration to avoid excessive weight reduction when applicable.

A proposal from the liver forum for the management of comorbidities in non-alcoholic steatohepatitis therapeutic trials

The current document has been developed by the Liver Forum who mandated the NAFLD-Associated Comorbidities Working Group - a multistakeholder group comprised of experts from academic medicine, industry and patient associations - to identify aspects of diverse comorbidities frequently associated with non-alcoholic steatohepatitis (NASH) that can interfere with the conduct of therapeutic trials and, in particular, impact efficacy and safety results. The objective of this paper is to propose guidance for the management of relevant comorbidities in both candidates and actual participants in NASH therapeutic trials. We relied on specific guidelines from scientific societies, when available, but adapted them to the particulars of NASH trials with the aim of addressing multiple interacting requirements such as maintaining patient safety, reaching holistic therapeutic objectives, minimising confounding effects on efficacy and safety of investigational agents and allowing for trial completion. We divided the field of action into: first, analysis and stabilisation of the patient's condition before inclusion in the trial and, second, management of comorbidities during trial conduct. For the former, we discussed the concept of acceptable vs. optimal control of comorbidities, defined metabolic and ponderal stability prior to randomisation and weighed the pros and cons of a run-in period. For the latter, we analysed non-hepatological comorbid conditions for changes or acute events possibly occurring during the trial, including changes in alcohol consumption, in order to detail when specific interventions are necessary and how best to manage concomitant drug intake in line with methodological constraints. These recommendations are intended to act as a guide for clinical trialists and are open to further refinement when additional data become available.

Quantifying weight loss program preferences of men working in trade and labor occupations: A discrete choice experiment

Objective

Men who work in skilled and unskilled trades and labor occupations (i.e., blue-collar occupations), have high rates of obesity and associated comorbidities but are underrepresented in weight loss programs. A first step in engaging this group is to better understand their preferences for weight loss programs.

Methods

Respondents were men working in trade and labor occupations, with overweight/obesity, and an interest in losing weight. A discrete choice experiment was developed, and the data were analyzed using mixed logit model. Respondent characteristics were tested as effect modifiers.

Results

Respondents (N = 221, age (M ± SD) 45.0 ± 12.6, BMI 33.3 ± 6.3, 77% non-Hispanic white) working in a variety of occupations (construction 31%, manufacturing 30%, transportation 25%, maintenance/repair 14%) participated in this study. Results indicate preferences for programs that encourage making smaller dietary changes, are delivered online, and do not incorporate competition. Results were consistent across sensitivity analyses and most respondent groups.

Conclusions

The results suggest specific ways to make weight loss programs more appealing to men in trade and labor occupations. Using experimental methods to quantify preferences using larger, more representative samples would further assist in tailoring behavioral weight loss programs for under-reached populations.

Pre-Enrollment Steps and Run-Ins in Weight Loss Trials: A Meta-Regression

INTRODUCTION

The generalizability of study findings may be influenced by pre-enrollment trial procedures, including the use of behavioral run-in periods. The study goals were to determine whether behavioral run-in periods and other pre-enrollment processes affect outcomes in randomized trials of behavioral weight loss interventions that have contributed to clinical guidelines.

METHODS

The sample was behavioral weight loss intervention trials included in the 2018 U.S. Preventive Services Task Force systematic review. Information on pre-enrollment processes (total steps, in-person steps, behavioral run-in) was abstracted, and meta-regressions were conducted in 2022 to test whether pre-enrollment processes were associated with weight loss at 6 or 12 months and trial retention at 12 months.

RESULTS

Across 80 trials, the median number of total pre-enrollment steps was 2 (range=1-5), and that of in-person pre-enrollment steps was 1 (range=0-4). Almost one-third of the trials (k=24; 30%) used a behavioral run-in. The most common run-in tasks were self-monitoring physical activity (k=9) or both physical activity and diet (k=6). Greater weight loss was observed in trials with behavioral run-ins at 6 months (-2.33 kg; 95% CI= -3.72, -0.93) and, to an attenuated extent, at 12 months (-0.86 kg; 95% CI= -1.72, 0.01) compared to those without run-ins. The total number of pre-enrollment steps was also associated with greater 6-month weight loss (-0.85 kg; 95% CI= -1.59, -0.11). Higher retention was associated with total number of pre-enrollment steps and in-person steps and marginally with the presence of run-ins.

DISCUSSION

The use of more pre-enrollment processes is associated with greater weight loss in behavioral weight loss trials and may impact the generalizability of outcomes.

Effect of a Run-In Period on Estimated Treatment Effects in Cardiovascular Randomized Clinical Trials: A Meta-Analytic Review

Background A run-in period may increase adherence to intervention and reduce loss to follow-up. Whether use of a run-in period affects the magnitude of treatment effects is unknown. Methods and Results We conducted a meta-analysis comparing treatment effects from 11 systematic reviews of cardiovascular prevention trials using a run-in period with matched trials not using a run-in period. We matched run-in with non-run-in trials by population, intervention, control, and outcome. We calculated a ratio of relative risks (RRRs) using a random-effects meta-analysis. Our primary outcome was a composite of cardiovascular events, and the primary analysis was a matched comparison of clinical trials using a run-in period versus without a run-in period. We identified 66 run-in trials and 111 non-run-in trials (n=668 901). On meta-analysis there was no statistically significant difference in the magnitude of treatment effect between run-in trials (relative risk [RR], 0.83 [95% CI, 0.80-0.87]) compared with non-run-in trials (RR, 0.88 [95% CI, 0.84-0.91]; RRR, 0.95 [95% CI, 0.90-1.01]). There was no significant difference in the RRR for secondary outcomes of all-cause mortality (RRR, 0.97 [95% CI, 0.91-1.03]) or medication discontinuation because of adverse events (RRR, 1.05 [95% CI, 0.85-1.21]). Post hoc exploratory univariate meta-regression showed that on average a run-in period is associated with a statistically significant difference in treatment effect (RRR, 0.94 [95% CI, 0.90-0.99]) for cardiovascular composite outcome, but this was not statistically significant on multivariable meta-regression analysis (RRR, 0.95 [95% CI, 0.90-1.0]). Conclusions The use of a run-in period was not associated with a difference in the magnitude of treatment effect among cardiovascular prevention trials.

Pretreatment and During-Treatment Weight Trajectories in Black and White Women

INTRODUCTION

Black participants often lose less weight than White participants in response to behavioral weight-loss interventions. Many participants experience significant pretreatment weight fluctuations (between baseline measurement and treatment initiation), which have been associated with treatment outcomes. Pretreatment weight gain has been shown to be more prevalent among Black participants and may contribute to racial differences in treatment responses. The purpose of this study was to (1) examine the associations between pretreatment weight change and treatment outcomes and (2) examine racial differences in pretreatment weight change and weight loss among Black and White participants.

METHODS

Participants were Black and White women (n=153, 60% Black) enrolled in a 4-month weight loss program. Weight changes occurring during the pretreatment period (41 ± 14 days) were categorized as weight stable (±1.15% of baseline weight), weight gain (≥+1.15%), or weight loss (≤-1.15%). Recruitment and data collection occurred from 2011 to 2015; statistical analyses were performed in 2021.

RESULTS

During the pretreatment period, most participants (56%) remained weight stable. Pretreatment weight trajectories did not differ by race (p=0.481). At 4-months, those who lost weight before treatment experienced 2.63% greater weight loss than those who were weight stable (p<0.005), whereas those who gained weight before treatment experienced 1.91% less weight loss (p<0.01).

CONCLUSIONS

Pretreatment weight changes can impact weight outcomes after initial treatment, although no differences between Black and White participants were observed. Future studies should consider the influence of pretreatment weight change on long-term outcomes (e.g., weight loss maintenance) along with potential racial differences in these associations. This study is registered (retrospectively registered) at ClinicalTrials.gov (NCT02487121) on June 26, 2015.

Effectiveness of "run-ins" at predicting adherence in a behavioral weight loss efficacy trial

There is limited research on whether run-in procedures predict participant adherence during behavioral efficacy trials. This study examined whether information from behavioral run-ins (food diary completion, questionnaire completion, and staff interview) predict intervention adherence, trial retention, and trial outcomes in a behavioral weight loss trial. Using run-in data, trial staff predicted which participants would have high, moderate, or low trial adherence. Participants with predicted high or moderate adherence were randomized. Results showed that predicted high adherers had better intervention adherence (session attendance and completion of self-monitoring records) and superior trial outcomes (i.e. weight loss). Run-in data did not predict trial retention. Results suggest that run-ins may be effective at identifying participants adherent to intervention protocols, thereby enhancing internal validity of behavioral efficacy trials.

Similar weight loss and maintenance in African American and White women in the Improving Weight Loss (ImWeL) trial

Objective: African Americans (AA) are often underrepresented and tend to lose less weight than White participants during the intensive phase of behavioral obesity treatment. Some evidence suggests that AA women experience better maintenance of lost weight than White women, however, additional research on the efficacy of extended care programs (i.e. continued contacts to support the maintenance of lost weight) is necessary to better understand these differences.Methods: The influence of race on initial weight loss, the likelihood of achieving ≥5% weight reduction (i.e. extended care eligibility), the maintenance of lost weight and extended care program efficacy was examined in 269 AA and White women (62.1% AA) participating in a 16-month group-based weight management program. Participants achieving ≥5% weight reduction during the intensive phase (16 weekly sessions) were randomized to a clustered campaign extended care program (12 sessions delivered in three, 4-week clusters) or self-directed control.Results: In adjusted models, race was not associated with initial weight loss (p = 0.22) or the likelihood of achieving extended care eligibility (odds ratio 0.64, 95% CI [0.29, 1.38]). AA and White women lost -7.13 ± 0.39 kg and -7.62 ± 0.43 kg, respectively, during initial treatment. There were no significant differences in weight regain between AA and White women (p = 0.64) after adjusting for covariates. Clustered campaign program participants (AA: -6.74 ± 0.99 kg, White: -6.89 ± 1.10 kg) regained less weight than control (AA: -5.15 ± 0.99 kg, White: -4.37 ± 1.04 kg), equating to a 2.12 kg (p = 0.03) between-group difference after covariate adjustments.Conclusions: Weight changes and extended care eligibility were comparable among all participants. The clustered campaign program was efficacious for AA and White women. The high representation and retention of AA participants may have contributed to these findings.

Assessing risk of bias: a proposal for a unified framework for observational studies and randomized trials

BACKGROUND

Evidence based medicine aims to integrate scientific evidence, clinical experience, and patient values and preferences. Individual health care professionals need to appraise the evidence from randomized trials and observational studies when guidelines are not yet available. To date, tools for assessment of bias and terminologies for bias are specific for each study design. Moreover, most tools appeal only to methodological knowledge to detect bias, not to subject matter knowledge, i.e. in-depth medical knowledge about a topic. We propose a unified framework that enables the coherent assessment of bias across designs.

METHODS

Epidemiologists traditionally distinguish between three types of bias in observational studies: confounding, information bias, and selection bias. These biases result from a common cause, systematic error in the measurement or common effect of the intervention and outcome respectively. We applied this conceptual framework to randomized trials and show how it can be used to identify bias. The three sources of bias were illustrated with graphs that visually represent researchers' assumptions about the relationships between the investigated variables (causal diagrams).

RESULTS

Critical appraisal of evidence started with the definition of the research question in terms of the population of interest, the compared interventions and the main outcome. Next, we used causal diagrams to illustrate how each source of bias can lead to over- or underestimated treatment effects. Then, we discussed how randomization, blinded outcome measurement and intention-to-treat analysis minimize bias in trials. Finally, we identified study aspects that can only be appraised with subject matter knowledge, irrespective of study design.

CONCLUSIONS

The unified framework encompassed the three main sources of bias for the effect of an assigned intervention on an outcome. It facilitated the integration of methodological and subject matter knowledge in the assessment of bias. We hope that graphical diagrams will help clarify debate among professionals by reducing misunderstandings based on different terminology for bias.

Standardisation of diet and exercise in clinical trials of NAFLD-NASH: Recommendations from the Liver Forum

Lifestyle modification is the foundation of treatment recommendations for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The design of clinical trials in NASH may be impeded by the lack of a systematic approach to identify and evaluate how lifestyle changes and/or modifications influence clinical trial outcomes and associated endpoints. Furthermore, there are additional uncertainties regarding the methods that can be utilised to better characterise and quantify lifestyle variables - which can influence disease activity and alter trial endpoints - to allow for comparisons of trial outcomes across different phases of research and/or within drug-classes. This summary by the Liver Forum's Standard of Care Working Group reviews currently available clinical data, identifies the barriers and challenges associated with the standard of care in NAFLD/NASH clinical trials, defines available assessments of lifestyle changes, and proposes approaches to better understand and define the influence of diet and exercise on NASH treatment in the context of different pharmacologic interventions. The ultimate objective is to propose tangible solutions which enable investigators, sponsors, and regulatory authorities to meaningfully interpret clinical trial outcomes and the impact of lifestyle modification on such outcomes as they pertain to phase I-IV clinical trials.

Placebo run-in periods in anticholinergic trials are not associated with treatment effect size or risk of attrition: an empirical evaluation

OBJECTIVES

We aimed to explore the impact of run-in periods on the magnitude of treatment effect and the risk of attrition in a sample of randomized trials.

STUDY DESIGN AND SETTING

We identified randomized trials from a published systematic review examining the effects of anticholinergics for the treatment of overactive bladders. We fitted meta-analytic mixed-effects models to assess whether the type of run-in (placebo run-in vs. no run-in) was associated with the magnitude of the effect estimates for the following outcomes: the number of voids per day, number of leakages per day, presence of dry mouth, cure/improvement, patient withdrawal from the trial, compliance with the trial protocol, and/or adherence to study drug. We adjusted for potential confounders.

RESULTS

A total of 96 trials met the eligibility criteria; 59 trials had no run-in (which included those with a screening or withdrawal period), 37 trials had a placebo run-in, and no trials had a drug run-in. The magnitude of the effect estimates for all outcomes did not importantly differ between trials with a placebo run-in and trials with no run-in. Adjustment for the confounding variables did not materially change the estimates.

CONCLUSION

The hypothesized benefits of placebo run-in periods were not observed in our sample of anticholinergic randomized trials for the treatment of overactive bladders. Designing future trials of anticholinergics with more pragmatic intentions is likely to result in evidence that more directly informs clinical decision-making.

Outcome of a psychosocial health promotion intervention aimed at improving physical health and reducing alcohol use in patients with schizophrenia and psychotic disorders (MINT)

BACKGROUND

Life expectancy is reduced by 19 years in men and 17 in women with psychosis in Sweden, largely due to cardiovascular disease.

AIM

Assess whether a psychosocial health promotion intervention improves cardiometabolic risk factors, quality of life, and severity of illness in patients with psychotic disorders more than treatment as usual.

METHODS

A pragmatic intervention trial testing a manual-based multi-component health promotion intervention targeting patients with psychosis. The Swedish intervention was adapted from IMPaCT therapy, a health-promotion program based on motivational interviewing and cognitive behavioral therapy, designed to be incorporated into routine care. The intervention group consisted of 119 patients and the control group of 570 patients from specialized psychosis departments. Outcome variables were assessed 6 months before intervention during the run-in period, again at the start of intervention, and 12 months after the intervention began. The control group received treatment as usual.

RESULTS

The intervention had no significant effect on any of the outcome variables. However, BMI, waist circumference, systolic BP, heart rate, HbA1c, general health, and Clinical Global Impressions Scale score improved significantly during the run-in period before the start of the active intervention (observer effect). The multi-component design meant that treatment effects could only be calculated for the intervention as a whole.

CONCLUSION

The results of the intervention are similar to those of the U.K. IMPaCT study, in which the modular health-promotion intervention had little effect on cardiovascular risk indicators. However, in the current study, the run-in period had a positive effect on cardiometabolic risk factors.

Randomized clinical trials with run-in periods: frequency, characteristics and reporting

Background

Run-in periods are occasionally used in randomized clinical trials to exclude patients after inclusion, but before randomization. In theory, run-in periods increase the probability of detecting a potential treatment effect, at the cost of possibly affecting external and internal validity. Adequate reporting of exclusions during the run-in period is a prerequisite for judging the risk of compromised validity. Our study aims were to assess the proportion of randomized clinical trials with run-in periods, to characterize such trials and the types of run-in periods and to assess their reporting.

Materials and methods

This was an observational study of 470 PubMed-indexed randomized controlled trial publications from 2014. We compared trials with and without run-in periods, described the types of run-in periods and evaluated the completeness of their reporting by noting whether publications stated the number of excluded patients, reasons for exclusion and baseline characteristics of the excluded patients.

Results

Twenty-five trials reported a run-in period (5%). These were larger than other trials (median number of randomized patients 217 vs 90, P=0.01) and more commonly industry trials (11% vs 3%, P<0.01). The run-in procedures varied in design and purpose. In 23 out of 25 trials (88%), the run-in period was incompletely reported, mostly due to missing baseline characteristics.

Conclusion

Approximately 1 in 20 trials used run-in periods, though much more frequently in industry trials. Reporting of the run-in period was often incomplete, precluding a meaningful assessment of the impact of the run-in period on the validity of trial results. We suggest that current trials with run-in periods are interpreted with caution and that updates of reporting guidelines for randomized trials address the issue.

Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation

BACKGROUND

Adults with severe obesity [body mass index (BMI) of ≥ 35 kg/m2] have an increased risk of comorbidities and psychological, social and economic consequences.

OBJECTIVES

Systematically review bariatric surgery, weight-management programmes (WMPs) and orlistat pharmacotherapy for adults with severe obesity, and evaluate the feasibility, acceptability, clinical effectiveness and cost-effectiveness of treatment.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials and the NHS Economic Evaluation Database were searched (last searched in May 2017).

REVIEW METHODS

Four systematic reviews evaluated clinical effectiveness, cost-effectiveness and qualitative evidence for adults with a BMI of ≥ 35 kg/m2. Data from meta-analyses populated a microsimulation model predicting costs, outcomes and cost-effectiveness of Roux-en-Y gastric bypass (RYGB) surgery and the most effective lifestyle WMPs over a 30-year time horizon from a NHS perspective, compared with current UK population obesity trends. Interventions were cost-effective if the additional cost of achieving a quality-adjusted life-year is < £20,000-30,000.

RESULTS

A total of 131 randomised controlled trials (RCTs), 26 UK studies, 33 qualitative studies and 46 cost-effectiveness studies were included. From RCTs, RYGB produced the greatest long-term weight change [-20.23 kg, 95% confidence interval (CI) -23.75 to -16.71 kg, at 60 months]. WMPs with very low-calorie diets (VLCDs) produced the greatest weight loss at 12 months compared with no WMPs. Adding a VLCD to a WMP gave an additional mean weight change of -4.41 kg (95% CI -5.93 to -2.88 kg) at 12 months. The intensive Look AHEAD WMP produced mean long-term weight loss of 6% in people with type 2 diabetes mellitus (at a median of 9.6 years). The microsimulation model found that WMPs were generally cost-effective compared with population obesity trends. Long-term WMP weight regain was very uncertain, apart from Look AHEAD. The addition of a VLCD to a WMP was not cost-effective compared with a WMP alone. RYGB was cost-effective compared with no surgery and WMPs, but the model did not replicate long-term cost savings found in previous studies. Qualitative data suggested that participants could be attracted to take part in WMPs through endorsement by their health-care provider or through perceiving innovative activities, with WMPs being delivered to groups. Features improving long-term weight loss included having group support, additional behavioural support, a physical activity programme to attend, a prescribed calorie diet or a calorie deficit.

LIMITATIONS

Reviewed studies often lacked generalisability to UK settings in terms of participants and resources for implementation, and usually lacked long-term follow-up (particularly for complications for surgery), leading to unrealistic weight regain assumptions. The views of potential and actual users of services were rarely reported to contribute to service design. This study may have failed to identify unpublished UK evaluations. Dual, blinded numerical data extraction was not undertaken.

CONCLUSIONS

Roux-en-Y gastric bypass was costly to deliver, but it was the most cost-effective intervention. Adding a VLCD to a WMP was not cost-effective compared with a WMP alone. Most WMPs were cost-effective compared with current population obesity trends.

FUTURE WORK

Improved reporting of WMPs is needed to allow replication, translation and further research. Qualitative research is needed with adults who are potential users of, or who fail to engage with or drop out from, WMPs. RCTs and economic evaluations in UK settings (e.g. Tier 3, commercial programmes or primary care) should evaluate VLCDs with long-term follow-up (≥ 5 years). Decision models should incorporate relevant costs, disease states and evidence-based weight regain assumptions.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016040190.

FUNDING

The National Institute for Health Research Health Technology Assessment programme. The Health Services Research Unit and Health Economics Research Unit are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.

A Feasible and Efficacious Mobile-Phone Based Lifestyle Intervention for Filipino Americans with Type 2 Diabetes: Randomized Controlled Trial

BACKGROUND

Filipino Americans have a high prevalence of obesity, type 2 diabetes (T2D), and cardiovascular disease compared with other Asian American subgroups and non-Hispanic whites. Mobile health (mHealth) weight loss interventions can reduce chronic disease risks, but these are untested in Filipino Americans with T2D.

OBJECTIVE

The objective of this study was to assess feasibility and potential efficacy of a pilot, randomized controlled trial (RCT) of a culturally adapted mHealth weight loss lifestyle intervention (Pilipino Americans Go4Health [PilAm Go4Health]) for overweight Filipino Americans with T2D.

METHODS

This was a 2-arm pilot RCT of the 3-month PilAm Go4Health intervention (phase 1) with an active waitlist control and 3-month follow-up (phase 2). The waitlist control received the PilAm Go4Health in phase 2, whereas the intervention group transitioned to the 3-month follow-up. PilAm Go4Health incorporated a Fitbit accelerometer, mobile app with diary for health behavior tracking (steps, food/calories, and weight), and social media (Facebook) for virtual social support, including 7 in-person monthly meetings. Filipino American adults ≥18 years with T2D were recruited from Northern California. Feasibility was measured by rates of recruitment, engagement, and retention. Multilevel regression analyses assessed within and between group differences for the secondary outcome of percent weight change and other outcomes of weight (kg), body mass index (BMI), waist circumference, fasting plasma glucose, HbA1c, and steps.

RESULTS

A total of 45 Filipino American adults were enrolled and randomized. Mean age was 58 (SD 10) years, 62% (28/45) were women, and mean BMI was 30.1 (SD 4.6). Participant retention and study completion were 100%, with both the intervention and waitlist group achieving near-perfect attendance at all 7 intervention office visits. Groups receiving the PilAm Go4Health in phase 1 (intervention group) and phase 2 (waitlist group) had significantly greater weight loss, -2.6% (-3.9 to -1.4) and -3.3% (-1.8 to -4.8), respectively, compared with the nonintervention group, resulting in a moderate to small effect sizes (d=0.53 and 0.37, respectively). In phase 1, 18% (4/22) of the intervention group achieved a 5% weight loss, whereas 82% (18/22) maintained or lost 2% to 5% of their weight and continued to maintain this weight loss in the 3-month follow-up. Other health outcomes, including waist circumference, BMI, and step counts, improved when each arm received the PilAm Go4Health, but the fasting glucose and HbA1c outcomes were mixed.

CONCLUSIONS

The PilAm Go4Health was feasible and demonstrated potential efficacy in reducing diabetes risks in overweight Filipino Americans with T2D. This study supports the use of mHealth and other promising intervention strategies to reduce obesity and diabetes risks in Filipino Americans. Further testing in a full-scale RCT is warranted. These findings may support intervention translation to reduce diabetes risks in other at-risk diverse populations.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02290184; https://clinicaltrials.gov/ct2/show/NCT02290184 (Archived by WebCite at http://www.webcitation.org/6vDfrvIPp).

Interventions that cause weight loss and the impact on cardiovascular risk factors: a systematic review and meta-analysis

Overweight and obesity increase the risks of diabetes and cardiovascular disease (CVD). This has been shown to be reversed with weight loss. A systematic review and meta-analysis were performed to determine the effect of weight loss in the primary prevention of CVD. PubMed, Embase and the Cochrane Library databases were searched electronically through to May 2013. Randomized controlled trials assessing weight loss and cardiovascular risk factors and outcomes were included. A random effects meta-analysis, with sub-group analyses for degree of weight loss, and age were performed. Because few studies reported clinical outcomes of CVD, analyses were limited to cardiovascular risk factors (83 studies). Interventions that caused any weight loss significantly reduced systolic blood pressure (-2.68 mmHg, 95% CI -3.37, -2.11), diastolic blood pressure (-1.34 mmHg, 95% CI -1.71, -0.97), low-density lipoprotein cholesterol (-0.20 mmol L(-1) , 95% CI -0.29, -0.10), triglycerides (-0.13 mmol L(-1) , 95% CI -0.22, -0.03), fasting plasma glucose (-0.32 mmol L(-1) , 95% CI -0.43, -0.22) and haemoglobin A1c(-0.40%, 95% CI -0.52, -0.28) over 6-12 months. Significant changes remained after 2 years for several risk factors. Similar results were seen in sub-group analyses. Interventions that cause weight loss are effective at improving cardiovascular risk factors at least for 2 years. © 2016 World Obesity.

Randomized controlled trials: who fails run-in?

BACKGROUND

Early identification of participants at risk of run-in failure (RIF) may present opportunities to improve trial efficiency and generalizability.

METHODS

We conducted a partial factorial-design, randomized, controlled trial of calcium and vitamin D to prevent colorectal adenoma recurrence at 11 centers in the United States. At baseline, participants completed two self-administered questionnaires (SAQs) and a questionnaire administered by staff. Participants in the full factorial randomization (calcium, vitamin D, both, or neither) received a placebo during a 3-month single-blinded run-in; women electing to take calcium enrolled in a two-group randomization (calcium with vitamin D, or calcium alone) and received calcium during the run-in. Using logistic regression models, we examined baseline factors associated with RIF in three subgroups: men (N = 1606) and women (N = 301) in the full factorial randomization and women in the two-group randomization (N = 666).

RESULTS

Overall, 314/2573 (12 %) participants failed run-in; 211 (67 %) took fewer than 80 % of their tablets (poor adherence), and 103 (33 %) withdrew or were uncooperative. In multivariable models, 8- to 13-fold variation was seen by study center in odds of RIF risk in the two largest groups. In men, RIF decreased with age (adjusted odds ratio [OR] per 5 years 0.85 [95 % confidence interval, CI; 0.76-0.96]) and was associated with being single (OR 1.65 [95 % CI; 1.10-2.47]), not graduating from high school (OR 2.77 [95 % CI; 1.58-4.85]), and missing SAQ data (OR 1.97 [1.40-2.76]). Among women, RIF was associated primarily with health-related factors; RIF risk was lower with higher physical health score (OR 0.73 [95 % CI; 0.62-0.86]) and baseline multivitamin use (OR 0.44 [95 % CI; 0.26-0.75]). Women in the 5-year colonoscopy surveillance interval were at greater risk of RIF than those with 3-year follow-up (OR 1.91 [95 % CI; 1.08-3.37]), and the number of prescription medicines taken was also positively correlated with RIF (p = 0.03). Perceived toxicities during run-in were associated with 12- to 29-fold significantly increased odds of RIF.

CONCLUSIONS

There were few common baseline predictors of run-in failure in the three randomization groups. However, heterogeneity in run-in failure associated with study center, and missing SAQ data reflect potential opportunities for intervention to improve trial efficiency and retention.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00153816 . Registered September 2005.

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

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.

Identifying Factors Associated With Dropout During Prerandomization Run-in Period From an mHealth Physical Activity Education Study: The mPED Trial

Background

The mobile phone-based physical activity education (mPED) trial is a randomized controlled trial (RCT) evaluating a mobile phone-delivered physical activity intervention for women. The study includes a run-in period to maximize the internal validity of the intervention trial, but little is known about factors related to successful run-in completion, and thus about potential threats to external validity.

Objective

Objectives of this study are (1) to determine the timing of dropout during the run-in period, reasons for dropout, optimum run-in duration, and relevant run-in components, and (2) to identify predictors of failure to complete the run-in period.

Methods

A total of 318 physically inactive women met preliminary eligibility criteria and were enrolled in the study between May 2011 and April 2014. A 3-week run-in period was required prior to randomization and included using a mobile phone app and wearing a pedometer. Cross-sectional analysis identified predictors of dropout.

Results

Out of 318 participants, 108 (34.0%) dropped out prior to randomization, with poor adherence using the study equipment being the most common reason. Median failure time was 17 days into the run-in period. In univariate analyses, nonrandomized participants were younger, had lower income, were less likely to drive regularly, were less likely to have used a pedometer prior to the study, were generally less healthy, had less self-efficacy for physical activity, and reported more depressive symptoms than randomized participants. In multivariate competing risks models, not driving regularly in the past month and not having used a pedometer prior to the study were significantly associated with failure to be randomized (P=.04 and .006, respectively), controlling for age, race/ethnicity, education, shift work, and use of a study-provided mobile phone.

Conclusions

Regular driving and past pedometer use were associated with reduced dropout during the prerandomization run-in period. Understanding these characteristics is important for identifying higher-risk participants, and implementing additional help strategies may be useful for reducing dropout.

Trial Registration

ClinicalTrials.gov NCT01280812; https://clinicaltrials.gov/ct2/show/NCT01280812 (Archived by WebCite at http://www.webcitation.org/6XFC5wvrP).

Effect of a 4-week weight maintenance diet on circulating hormone levels: implications for clinical weight loss trials

The majority of weight loss studies fail to standardize conditions such as diet and exercise via a weight maintenance period prior to commencement of the trial. This study aimed to determine whether a weight stabilization period is necessary to establish stable baseline hormone concentrations. Fifty-one obese male participants with a body mass index of 30-40 kg m(-2) and aged 25-54 years underwent 4 weeks on an energy balance diet that was designed to achieve weight stability. Blood samples were collected in the fasting state at commencement and completion of the 4-week period, and circulating concentrations of 18 commonly measured hormones were determined. During the 4-week weight maintenance period, participants achieved weight stability within -1.5 ± 0.2 kg (-1.4 ± 0.2%) of their initial body weight. Significant reductions in serum insulin (by 18 ± 6.5%) and leptin (by 21 ± 6.0%) levels occurred, but no significant changes were observed for gut-derived appetite-regulating hormones (ghrelin and peptide YY), nor thyroid, adrenal, gonadal or somatotropic hormones. There were no significant correlations between the change in body weight and the change in circulating concentrations of insulin or leptin over the 4-week period, indicating that the observed changes were not due to weight loss, albeit significant negative correlations were observed between the changes in body weight and plasma ghrelin and peptide YY levels. This study demonstrates the need for baseline weight maintenance periods to stabilize serum levels of insulin and leptin in studies specifically investigating effects on these parameters in the obese. However, this does not apply to circulating levels of gut-derived appetite-regulating hormones (ghrelin and peptide YY), nor thyroid, adrenal, gonadal or somatotropic hormones.