Читать книгу Applied Biostatistics for the Health Sciences - Richard J. Rossi - Страница 20

In a study designed to determine the percentage of obese adults in the United States, the BMI of 500 adults was measured at several hospitals across the country. The resulting percentage of the 500 adults classified as obese was 24%.

In this study, the target population was adults in the United States, 500 adults constitute a sample of the adults in the United States, the parameter of interest is the percentage of obese adults in the United States, and 24% is a statistic since it was computed from the sample, not the target population.

In designing a biomedical research study, the statistical protocol used in the study is usually determined by the research team in conjunction with the biostatistician. The statistical protocol should include the identification of the target population, the units in the population, the response variable and explanatory variables, the parameters of interest, the treatments or subpopulations being studied, the sample size, and models that will be fit to the observed data.