Sample Size and Statistical Analyses
The specified sample size of 32 subjects was based on the capacity
to detect a clinically significant change (0.5 points per item)
in HRQOL (activity limitation domain of the AQLQ) and a
54-metre change in 6MWD between groups with 80% power
( = 0.05) [23–26] . Data were analysed according to the intentionto-
treat principle. Three-month follow-up data were unavailable
for 3 subjects in the control group and missing data for these subjects
were replaced using the last observation carried forward
method [27] . Baseline equivalence of groups was tested using unpaired
t tests, Mann-Whitney tests and 2 analysis as appropriate.
Data for the primary and secondary outcome measures were analysed
using a 2 ! 3 repeated-measures ANOVA. Post hoc contrasts
were specified for differences between groups at the postintervention
assessment and at the 3-month follow-up. Data are
expressed as means 8 SD with differences between groups expressed
as means and 95% confidence intervals. All statistical
analyses were performed using SPSS software (version 16).