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.
Gunnarsdóttir
I
I
Unit for Nutrition Research, Landspítali University Hospital and University of Iceland, Reykjavík, Iceland. ingigun @ landspitali.is
Sigurgeirsdóttir
G K
GK
Thórsdóttir
I
I
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