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I am healthcare professional with minimal knowledge on statistics.
I am comparing 2 anti-hypertensives for their efficacy in lowering blood pressure, Drug A is the current standard treatment and Drug B is a new drug which was expected to be more effective in lowering blood pressure.
Therefore, my null hypothesis will be there is no difference between efficacy of Drug A and Drug B in lowering BP. Alternative hypothesis will be drug B is more effective than Drug A in lowering blood pressure.
I know I have to use Kolmogorov-Smirnov Test to test for normality before using t-test or Mann-Whitney to test for significance.
The question here is, from what i understand is that the p-value should be halved for t-test or Mann-Whitney as my hypothesis is one-tailed, but how about p-value for Kolmogorov-Smirnov? Do we keep with p<0.05 or halved it to p<0.025? (I think i supposed to run one-sample KS test using blood pressure to test for normality)
Thanks, if can please explain in layman terms as I do not have statistical background.