Participants who were difficult to recruit at baseline are less likely to complete a follow-up questionnaire - results from the German National Cohort.

摘要: With declining response proportions in population-based research the importance of evaluating effectiveness measures aimed at improving increases. We investigated whether an additional flyer with information about study influences participation a follow-up questionnaire and time participants take to send back filled questionnaire. In trial embedded within German National Cohort we compared responses invitations for either including cohort or not it. Outcomes interest were (yes vs. no) (in days). analyzed paradata from baseline recruitment account differences history between participants. Adding did neither influence likelihood (OR 0.94, 95% CI: 0.80, 1.11), nor it took return completed questionnaires (β = 1.71, − 1.01, 4.44). Subjects who, baseline, needed be reminded before eventually participating examinations subjects who scheduled three more appointments until completing less likely complete and, if they did, questionnaires. Evaluating increasing can help improve allocation usually limited resources. Characteristics studies therefore (i.e., paradata) might prove useful tailor recruitments those difficult recruit during baseline. To this end, however, is necessary routinely meticulously collect recruitment.