Skip to main content
Fig. 1 | BMC Medical Research Methodology

Fig. 1

From: Recruitment into antibody prevalence studies: a randomized trial of postcards vs. letters as invitations

Fig. 1

Number and percent of individual households assigned to either letter or postcard invitations at each of the two mailings. Pink indicates randomization to a letter (L) or a postcard (P); numbers of responses (R) and response rates are bright yellow for the first mailing, bright blue for the second mailing and bright green for the combination of mailing types; numbers of non-respondents (NR) are in pale yellow for the first mailing and pale blue for the second mailing. Denominators for the combination mailing rates include those who responded to the first mailing in addition to those assigned to the category for the second mailing. (Note that in this figure the second mailing rate does not include the initial responses.)

Back to article page

BMC Medical Research Methodology

ISSN: 1471-2288

Contact us