Passive imputation and parcel summaries are both valid to handle missing items in studies with many multi-item scales

Previous studies showed that missing data in multi-item scales can best be handled by multiple imputation of item scores. However, when many scales are used, the number of items will become too large for the imputation model to reliably estimate imputations. A solution is to use passive imputation or a parcel summary score that combine and...

The effects of physical activity and fitness in adolescence on cognition in adulthood and the role of insulin-like growth factor I

Background: Physical activity and fitness in adolescence may improve cognition in adulthood by increasing insulin-like growth factor I (IGF-I). Methods: As part of the Amsterdam Growth and Health Longitudinal Study, following subjects from age 13 to 42 years, physical activity and fitness of 303 subjects were assessed annually between the ages...

Sensitivity to coffee and subjective health

The question was whether health complaints are associated with coffee consumption and self reported sensitivity to coffee. Participants were 89 men and 107 women, all coffee drinkers. Questionnaires were used at 2 points of time with an interval of 3.7 years. The correlations among coffee consumption, sensitivity and health complaints were...