Changes

When cluster or multistage sampling techniques are used, the effect of clustering of the outcome of interest within clusters will have an effect on the required sample size, since animals within the same cluster would be expected to be more similar to each other than to those from other clusters. Therefore, formulas are available in order to calculate the 'design effect' (or DEFF), which indicates the factor by which the calculated sample size needs to be increased by in order to account for this.

When cluster or multistage sampling techniques are used, the effect of clustering of the outcome of interest within clusters will have an effect on the required sample size, since animals within the same cluster would be expected to be more similar to each other than to those from other clusters. Therefore, formulas are available in order to calculate the 'design effect' (or DEFF), which indicates the factor by which the calculated sample size needs to be increased by in order to account for this.

===Multivariate studies===

===Multivariable studies===

When the effect of confounding or interaction is to be accounted for in the study, the sample size needs to be increased accordingly.

When the effect of confounding or interaction is to be accounted for in the study, the sample size needs to be increased accordingly.

[[Category:Veterinary Epidemiology - General Concepts|F]]

[[Category:Veterinary Epidemiology - General Concepts|F]]