CPH Exam questions with correct answers

It is well recognized that one of the easiest ways to increase statistical power is to increase the sample size. Which of the following could also be used to increase power in a study. - correct answer Reduce error through using appropriate methods **Power is primarily influenced by two things, sample size and variability. Power increases as sample size increases or variability decreases. Variability includes two parts, true variability and error varibility. We collected 100 samples of size thirty of household income in Arkansas with population mean, mu=50 (in thousands). the sample mean, X and sample standard deviation, s, were recorded and the 95% confidence interval for mu was taken for each sample. Given the 100 confidence intervals, how many do you expect to cover the population mean mu=50? - correct answer 95 **A 95% confidence interval implies that were the estimation process repeated again and again, the 95% of the calculated intervals would be expected to contain the true parameter value mu=50. Randominzation, stratified analysis, and matching - correct answer minimize confounding Which of the following about the stage of change from the Transtheoretical Model is true - correct answer Action refers to behavior change for less than 6 months The best time to prepare an evaluation plan for a health intervention program is: - correct answer During the program planning period **An evaluation perspective when applied during planning can assure that the program intervention is specific enough to support rigorous evaluation A major obstacle to risk communication effectiveness is that most risks are derived from uncertainty, complexity, and incompleteness of environmental data. Which of the following are