Pairwise statistical comparisons between baseline parameters at diagnosis (Dx) and BL-Ilo were performed using a t-test if the data were normally distributed according to the Kolmogorov-Smirnov-test. Otherwise a nonparametric U-test was carried out.
The aim of this study was to examine in patients with clinically stable complex COPD the relationship between functional baseline parameters and exercise response to PR and to ascertain whether or not baseline lung function could predict a benefit in terms of a significant change in 6MWT after PR.
Associations between baseline parameters will be examined.
After testing normality by the Kolmogorov-Smirnov test, significance of differences between baseline parameters in the two groups was tested by unpaired t-test, when normality test succeeded, and by Mann-Whitney test, when normality test failed.
To evaluate potential differences between baseline parameters in unpaired groups, we used a 2-level linear mixed regression model with a patient as a random effect to control for the correlation of measurements made in the same patient with adjustment for age and sex.
Potential correlations amongst baseline parameters and between baseline parameter values and reproducibility values were assessed using Spearman's rho coefficient test (two-sided).
As all of our study subjects were without cardiovascular complications at baseline and gender was well matched between groups, it was likely that the baseline parameters and drug treatment affected the outcomes.
The association between each baseline parameter and radiographic progression was tested using unadjusted logistic regression (table 2).
First, a large prospective study in older adults with SVD [18] reported a relation between baseline diffusion parameters and decline in executive function, memory and speed after a follow-up period of 3 years, after adjustment for age, sex, education, TBV, WMH and lacunes.
The third study (n = 84) in middle-aged community dwelling individuals found no correlations between baseline DTI parameters and changes in working memory, but showed that decline in working memory was correlated to decline in DTI parameters after 2 years [16].
