Development of a Sampling Strategy and Sample Size Calculation to Estimate the Distribution of Mammographic Breast Density in Korean Women

Mammographic breast density is a known risk factor for breast cancer. To conduct a survey to estimatethe distribution of mammographic breast density in Korean women, appropriate sampling strategies forrepresentative and efficient sampling design were evaluated through simulation. Using the target populationfrom the National Cancer Screening Programme (NCSP) for breast cancer in 2009, we verified thedistribution estimate by repeating the simulation 1,000 times using stratified random sampling to investigatethe distribution of breast density of 1,340,362 women. According to the simulation results, using a samplingdesign stratifying the nation into three groups (metropolitan, urban, and rural), with a total sample size of4,000, we estimated the distribution of breast density in Korean women at a level of 0.01% tolerance. Basedon the results of our study, a nationwide survey for estimating the distribution of mammographic breastdensity among Korean women can be conducted efficiently.