“…With reference to results from a previous study [19], a total sample size of 80 participants, 40 per arm, are required to detect 2 points difference in HFNS mean score at 6 weeks using regression analysis controlling for baseline level of the outcome, with a 90% power at 2 tailed significance 0.05 level, assuming equal SD (3.0) for both groups and correlation between baseline and follow up RUNNING HEAD: MENOS@WORK 8 measures at 0.4 for the purpose of being conservative. After taking into account 20% loss to follow up rate, a sample size of 100 is required.…”