Predictors of dropping out in a weight loss intervention trial.
OBJECTIVE
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.
Unit for Nutrition Research, Landspítali University Hospital and University of Iceland, Reykjavík, Iceland. ingigun @ landspitali.is
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Gunnarsdóttir
G K
GK
Sigurgeirsdóttir
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Thórsdóttir
D000328:Adult; D000886:Anthropometry; D000928:Antidepressive Agents; D001628:Beverages; D015992:Body Mass Index; D003362:Cost-Benefit Analysis; D004032:Diet; D004435:Eating; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008019:Life Style; D016015:Logistic Models; D008297:Male; D050177:Overweight / Q000178:diet therapy*; D010352:Patient Dropouts; D018579:Patient Selection; D011237:Predictive Value of Tests; D055105:Waist Circumference; D015431:Weight Loss / Q000502:physiology*; D055815:Young Adult
D000928:Antidepressive Agents