Table 2:
Sample size calculations
§
.
Measure
Instrument
Definition
Hypothesized mean (SD) control group
Hypothesized mean (SD) intervention group
Sample size (total)
Anxiety
HADS
Mean differences between baseline and postintervention
3.0
5.1
42
§
Null hypothesis Ho = mean difference in pre- /post-HADS score in intervention group = mean difference in pre- /post-HADS score in control group;
α
(two-tailed) = 0.05 and 1−
β
= 0.8.