Sample size calculations:

The research question is whether there is a difference in the efficacy of Study drug A and Study drug B (which is the standard of care) for the treatment of type 2 diabetes. The investigator has planned a quadruple blind randomized clinical trial to study whether the study drug Ais effective in reducing glycosylated hemoglobin (HbA1c) as compared to study drug B (standard of care ) in participants with Type 2 Diabetes after 12 weeks.

A previous study has reported the mean HbA1C level in subjects treated for diabetes is 8 %(% here is a unit of measure)with a standard deviation of2%(% here is a unit of measure).The investigator would like to be able to detect a difference of20%or more in the mean HbA1C levels between the two groups

Please note: HbA1c is measured and expressed in percentage as units and not as a percentage of proportions.

Use a two-sided = 0.05

And power 0.80.

Calculate the sample size (Answer points 1 - 6)

Now, considering a10% dropout ratewhat would be the increased sample size. (Answer point 7)

State in details:

1. The null hypothesis
2. The alternative hypothesis
3. Type of test to be used and justification for its use
4. The information provided
5. Steps for calculating the sample size
6. Final answer
7. Calculations for sample size considering the dropout rate