Statistical Analysis
SAS version 9.2k was used to analyze the data. To evaluate the effect of intervention over time within each treatment group, paired t tests were performed. The change in measurement from pre-training to post-training was compared between groups using an analysis of variance model with treatment as factor and the premeasure level as a covariate. Treatment differences were estimated from the model. Significant differences between groups are presented as mean change with 95% confidence intervals (CIs) and P values. All other values are presented as mean _ standard error of the mean (SEM). All tests were 2-tailed, and P values less than .05 were considered significant.