https://communities.sas.com/t5/SAS-Programming/power-analysis-calculate-the-sample-size-needed/m-p/580436#M164885 <P>Use proc power with statement onesamplefreq.Specify PROPORTION=0.4 and NULLPROPORTION=0.5. Read the documentation.</P> Sun, 11 Aug 2019 22:09:19 GMT PGStats 2019-08-11T22:09:19Z https://communities.sas.com/t5/SAS-Programming/power-analysis-calculate-the-sample-size-needed/m-p/580427#M164883 <P>Could any one please provide me with the SAS code I should use for this task?</P><P>The rate of a type of disease in the general population is<SPAN>&nbsp;</SPAN><STRONG>50%</STRONG>, and I am giving a group of randomly selected people a type of vitamin to observe if the vitamin can decrease the rate of disease in this treatment group. I want to be able to identify the significant effect as long as there is<SPAN>&nbsp;</SPAN><STRONG>40%</STRONG><SPAN>&nbsp;</SPAN>rate of this disease in my treatment group at alpha .05 and power .80. What sample size minimally I should have?</P><P>Thank you so much!</P> Sun, 11 Aug 2019 20:43:21 GMT https://communities.sas.com/t5/SAS-Programming/power-analysis-calculate-the-sample-size-needed/m-p/580427#M164883 Lindy 2019-08-11T20:43:21Z https://communities.sas.com/t5/SAS-Programming/power-analysis-calculate-the-sample-size-needed/m-p/580436#M164885 <P>Use proc power with statement onesamplefreq.Specify PROPORTION=0.4 and NULLPROPORTION=0.5. Read the documentation.</P> Sun, 11 Aug 2019 22:09:19 GMT https://communities.sas.com/t5/SAS-Programming/power-analysis-calculate-the-sample-size-needed/m-p/580436#M164885 PGStats 2019-08-11T22:09:19Z