Statistical calculations were performed using MINITAB Statistical
Software, Release 13 for Windows, 2000 (Minitab
Inc., State College, PA, USA). To test for differences
between the intervention and control groups on key
variables at baseline, chi-squared or independent samples
t-test were used. To assess differences in the change over
the 4-month period between the two groups, general linear
model analysis was used to test the difference in the
mean individual change between baseline and follow-up
scores for each outcome variable, adjusted for age, sex,
years of education and baseline score for that variable. The
difference between the exercise and control groups on the
CIBIC-plus rating of change was analysed using Kruskall–
Wallis test, comparing median change scores at follow-up.