The Stroke Prevention in Young Adults Study was a population-based, case-control study of people in the Baltimore-Washington area aged 15-49 years who either had a first ischemic stroke between 1992 and 2008 or were age-matched controls without stroke who were contacted by random-digit dialing
. Investigators collected data through a standardized interview.
The 460-question survey is being administered to 500 respondents identified through random-digit dialing
The Bureau also conducts contract survey research and offers a random-digit dialing
program for survey organizations in need of random telephone samples.
English-speaking Seattle residents aged 18-39 were contacted by telephone through random-digit dialing
. Census blocks where blacks represented 40% or more of the population were oversampled, to ensure sufficient black respondents.
identified two matched control subjects per patient.
using industry standard random-digit dialing
techniques from a representative sampling provided by Survey Sampling Inc.
The NPF survey used random-digit dialing
to query 27,000 Americans 18 years of age or older during November through December 2001.