%0 Journal Article
%T Scratch lottery tickets are a poor incentive to respond to mailed questionnaires
%A Vilhjalmur Finsen
%A Andreas H Storeheier
%J BMC Medical Research Methodology
%D 2006
%I BioMed Central
%R 10.1186/1471-2288-6-19
%X 1500 randomly selected Norwegians between the ages of 40 and 65 years were sent a short questionnaire. 250 received one lottery scratch ticket worth 20 Norwegian kroner (approximately 3 US$) together with the questionnaire, 250 received two scratch tickets, and 250 were promised two scratch tickets if they replied within one week. A fourth group of 250 persons received a 50 kroner banknote with the questionnaire. The remaining 500 letters served as controls.The overall response rate after 6 weeks was 77%. Logistic regression analysis showed that only the 50 kroner group had a response rate that was statistically significantly higher than the controls (p < 0.0001). It was also significantly higher than that in any of the other incentive groups (p < 0.0001, p < 0.004 and p < 0.0001 respectively). Female sex (p < 0.001) and age (p < 0.002) increased the response rate significantly.It is possible that the recipients scratched their cards before completing the questionnaire, and that it was a disincentive for the majority that they did not win anything. Lottery scratch tickets are no substitute for cash as an incentive to respond to a questionnaire.A great effort is usually made to induce as many as possible to reply in any study employing questionnaires. Many of the factors that influence the response rate, such as the interest to the recipient of the subject under investigation and the length of the questionnaire, can not easily be altered [1,2]. It has been shown that the response rate may be increased by incentives like using impressive postage stamps [3] offering participation in a lottery [4,5] and particularly by enclosing money [1,6-12]. However, sending cash in the mail is frowned upon by the postal authorities in many countries and some recipients might be offended by being offered money to participate in a scientific investigation.The purpose of this study was to test if scratch lottery tickets used in various ways might serve as a substitute for cash.A list o
%U http://www.biomedcentral.com/1471-2288/6/19