Predictors of Dropping Out in a Weight Loss Intervention Trial

Abstract

Background/Aim: Dropouts in intervention trials can affect the statistical power of the study. The aim was to assess predictors of dropping out in a weight loss trial. Methods: Each subject (n = 114) was instructed to follow a diet, energy-restricted by 30% from estimated energy expenditure (approximately 600 kcal/day), for 8 consecutive weeks. A detailed meal plan as well as recipe booklets and instructions were provided by a nutritionist. Results: Antidepressants were used by 19.2% of the dropouts, compared with 1.8% of the completers (p < 0.001). Additionally, those dropping out consumed 35% more soft drinks in total and 44% more diet (artificially sweetened) soft drinks at baseline (habitual intake) than those completing the trial (p = 0.012). Dropouts (18.6%) were on average 1.9 years younger than those completing the study, but the difference was of borderline significance (p = 0.085). Conclusions: The use of antidepressants and heavy habitual soft drink consumption might be considered as exclusion criteria when preparing weight loss intervention trials including dietary restrictions.

Is drop-out from obesity treatment a predictable and preventable event?

“…The findings from our current study are generally in agreement with the majority of previous reports in the field [3,7-15,17,18] although the results were not always consistent [6,8,9,12] and sporadically even were at variance [5,11]. There are several potential reasons that may account for the discrepant findings across studies, including differences in the study settings, the number and characteristics of the subjects recruited, and the type of weight loss protocols.…”

“…To date, most studies focusing on attrition rates and/or its predictors have been based on pre-treatment data (e.g., weight and presence of comorbidities) routinely collected for other purposes (e.g., identifying predictors and correlates of weight loss) [3-8]. High drop-out rates from obesity treatment have been associated with baseline characteristics such as young age [3,9-11], low education levels [6,9,12], poor dieting behaviors [3,5,8,12,13], and unhealthy lifestyles [12-15].…”

“…High drop-out rates from obesity treatment have been associated with baseline characteristics such as young age [3,9-11], low education levels [6,9,12], poor dieting behaviors [3,5,8,12,13], and unhealthy lifestyles [12-15]. However, the literature on predictors of attrition in obesity treatment is limited by different study designs and inconsistencies across studies.…”

“…Because some results may be population-specific [24,25], we also sought to replicate in an Italian academic setting the previously identified predictors of drop-out [1,3-19]. …”

Factors associated with dropout in a group weight‐loss programme: a longitudinal investigation

“…To the best of our knowledge, this is the first study to include such intensive statistical analyses. Most previous studies used univariate analyses (Pekarik et al, 1984;Bennett & Jones, 1986;Sitton & Miller, 1991;Messier et al, 2010;Handjieva-Darlenska et al, 2011) or multiple logistic regression (Chang et al, 2009;Greenberg et al, 2009;Gunnarsdottir et al, 2010) to study the predictors of dropout in weight-loss interventions. Only a few separated early and late dropout (Pekarik et al, 1984;Bennett & Jones, 1986;Sitton & Miller, 1991;Yass-Reed et al, 1993;Chang et al, 2009).…”