sample size calcuation

[May Hassan]

using the command here : power twoproportions 0.2 0.55, test(chi2) effect(ratio) nratio(0.66666666666) continuity . my sample size is 72
N1 = 43
N2 = 29
N2/N1 = 0.6744 .
However I expect 20% loss to follow in the whole sample ,, so how to perform the analysis in Stata 18 ?

Thank you!

[Joseph Coveney]

. . . I expect 20% loss to follow in the whole sample ,, so how to perform the analysis in Stata 18 ?

Are you looking for something like this?

display in smcl as text "Accommodating 20% attrition: " as result ceil(43 / 0.8)
display in smcl as text "Accommodating 20% attrition: " as result ceil(29 / 0.8)

[May Hassan]

[QUOTE=Joseph Coveney;n1750543]Are you looking for something like this?

display in smcl as text "Accommodating 20% attrition: " as result ceil(43 / 0.8)
display in smcl as text "Accommodating 20% attrition: " as result ceil(29 / 0.8)

[/QUOTE

Yes , Thank you!