2.5. Sample Size Estimation
The total sample size of 106 women was estimated for an expected effect size of 0.55 and power of 0.8 at an alpha of 0.05 [22]. This would be sufficient to detect a five point difference between groups in the PCS score of SF-36v2 on completion of the intervention, assuming a SD of 9.1 [16]. Taking into consideration possible dro- pouts, we recruited 120 women for the study.