 The study investigates the variation in exposure outcome relationships in studies of the same population with different response rates and designs by comparing estimates from the 45 and up study, self-administered postal questionnaire, response rate 18%, and the New South Wales Population Health Survey, computer-assisted telephone interview, response rate 60%. The study found that for highly comparable questionnaire items, exposure outcome relationship patterns were almost identical between the two studies and ours for eight of the 10 relationships examined did not differ significantly. However, for questionnaire items that were only moderately comparable, the nature of the observed relationships did not differ materially between the two studies, although many ours differed significantly. The findings suggest that for a broad range of risk factors, two studies of the same population with varying response sampling frame and mode of questionnaire administration yielded consistent estimates of exposure outcome relationships. However, ours varied between the studies where they did not use identical questionnaire items. This article was authored by John Louisa, Banks Emily, Mealing Nicole M and others. We are article.tv, links in the description below.