In a study designed to determine the incidence of hypertension (high blood pressure) in an inner‐city community, a sample of residents is selected for examination.Which
Of the following sampling methods is likely to lead to the least bias?

Question

Quizplus · Accepted Answer

You would definitely not want to use a call for volunteers in a local paper (A), this
will give a highly selected sample as it won't include people who don't get or don't read the
local paper.Similarly shoppers eager to get home will refuse, and those who don't use the
supermarket won't be included so D is not ideal.GP records (C) in most countries won't give
population coverage, so you would only get those who have presented because of illness and
have no idea of the prevalence in the rest of the population.B is the ideal sampling frame,
although it too is challenging because if you don't get a high participation rate your findings
may still be misleading.

In a Study Designed to Determine the Incidence of Hypertension