--- imach/html/doc/imach.htm 2004/06/16 21:35:20 1.2 +++ imach/html/doc/imach.htm 2004/06/16 22:45:51 1.3 @@ -1,4 +1,4 @@ - + @@ -1008,7 +1008,7 @@ href="biaspar/vplrbiaspar.txt">biaspa

The period prevalence has to be compared with the cross-sectional prevalence. But both are statistical estimates and therefore have confidence intervals. -For the cross-sectional prevalence we generally need information on +
For the cross-sectional prevalence we generally need information on the design of the surveys. It is usually not enough to consider the number of people surveyed at a particular age and to estimate a Bernouilli confidence interval based on the prevalence at that