Statistical analysis
Power calculations were performed based on data
from prior published studies, using an alpha level
of 0.05 and power of 0.8.21–25 Accounting for attrition,
each group was estimated to need approximately
50 participants.14
Coded data for all outcome measures and relevant
independent measures were transferred by the
blinded evaluators to data management and analysis
personnel. These data were then transferred
from hardcopy recordings to a menu-driven webbased
SQL data entry system (PTClinResNet), and
then exported to SAS version 8.2 (SAS Institute
Inc., Cary, NC, USA) for statistical analysis.14
A two-group, pretest-posttest (repeated measure)
design was originally planned. However, some
of the participants did not adhere with the random