Sample size calculation:Sample size was calculated using minimum 95% confidence interval and 95% power of the study for one group in which observation will be taken in six times as repeated design. Assuming 0.28 standard deviation of the effect size of the mean difference, calculated sample size came out to be 23. Finally for this study, sample size has been taken 25. PASS-8 (Power and sample size) software version 8 have been used to calculate sample size.