Cluster Sample Size Calculator Aberdeen. If cost savings can be used to increase sample size and improve precision cluster samples may be a good choice. The Optimal Sample Sizes for Two-Stage Cluster Sampling in Demographic and Health Surveys Alfredo Aliaga and Ruilin Ren ORC Macro July 2006 Corresponding author.
You are interested in the average reading level of all the seventh-graders in your city. Jun 30 2011 Cluster randomised controlled trials CRCTs are frequently used in health service evaluation. Mar 01 2004 Reflecting these issues the sample size calculator was developed to both.
To achieve 90 power with seven clusters in each arm cluster size should be 1383 yielding a total sample size of 19362 table 1.
T-value21962times the original sample size and then recalculates the total sample size and number of clusters. A sample size calculator is presented for calculating appropriate sample sizes for cluster trials whilst allowing the implications of both methods of inflation to be considered. 1n-1ρ where n is the average cluster size and ρ is the ICC for the desired outcome to accommodate for the lack of independence in the data. Sometimes though cluster samples are less costly to administer.
