Effect sizes (ES) were also determined to explore
the degree to which the PR program was responsible
for changes in activities limitation resulting from
breathlessness, HRQOL, muscle strength, exercise tolerance,
and functional balance. ESs were calculated as
the mean difference in values before and after PR
divided by the mean standard deviation (ie, mean ±
SD before and after PR) using G*Power Software 3.1.1
(Kiel, Germany). The magnitudes of the ES were
interpreted as ≥ 0.2 small effect, ≥ 0.5 medium effect,
and ≥ 0.8 large effect. 14 The level of significance considered
was 0.05.