sample size calculation for surveys


I am wondering if anyone knows how the sample size for HCAHPS mode study completed in 2007 ( were calculated?

The standard errors for the mode adjustments are presented on the last page here: of Mode Adj_122106.pdf

I am wondering oh how I should go about to calculating the sample size to revalidate the study and mode adjustment point estimates. If the standard errors are presented at the hospital level, can I use that to calculate the number of patients I need. It seems like the standard errors are also quite large compared to the point estimates. Is the concern the precision of the mode adjustment or precision of the scores after mode adjustments.

If anyone can help that would be great. Thanks