Both the p-value and the reported 95% confidence intervals were adjusted for the multistage stratified cluster sample
design of the study.
Here we report the incidence rate of leprosy in this multistage random cluster sample
from the general population over a 6-year observation period and describe the main characteristics of the patients found.
A simple means of ascertaining the required sample size for a cluster sample
is to calculate the required sample size based on simple random sampling and then inflate this figure by the design effect, obtaining an adjusted sample size with the power required for the study.
The TIMSS 2007 assessment employed a two-stage stratified cluster sample
design (Joncas, 2008).
Mortality Before and After the 2003 Invasion of Iraq: Cluster Sample
Survey," The Lancet, October 29, 2004, 364 (9448), pp.
The survey used a three-stage cluster sample
design to obtain cross-sectional data representative of the nation's high school students.
This means that the number of subjects needed for a cluster sample
is larger than for a study of the same power in which individual subjects are randomly sampled (2,3).
Using this method, in addition to a cluster sample
counting technique, we conducted exit count surveys at a reasonable cost, and we obtained statistical confidence values.
A common study design in health services research is the multistage cluster sample
(Kish 1965) to abstract data from medical records.
A two-stage cluster sample
was used to select a representative sample of 97 schools.
A cross-sectional survey of a cluster sample
of primary care patients in California and Canada revealed patients' requests for medicines are a powerful influence on prescribing decisions.
In stage 1, a stratified random cluster sample
of 60 primary care clinicians was selected, 15 in each of the strata.