Four weeks after the initial mailing, non-respondents were mailed a second cover letter and survey reiterating our interest in their participation.
About two weeks later, non-respondents are mailed a second survey along with a cover letter, a pen, and a postage paid return envelope.
A total of 146 eligible survivors were mailed a second copy of the SUNS; of these, 125 returned a completed survey (86%).
Non-responders were mailed a second questionnaire package approximately 4 weeks later, and contacted via telephone after a further 4 weeks.
At 6 months after consenting, all the women were mailed a second self-administered questionnaire; 51 (92.7%) and 56 (93.3%) women, respectively, in the Internet and control groups responded.
Nonrespondents were mailed a second questionnaire if they had not responded in one calendar month and then contacted by telephone if they had not returned this second questionnaire within a further month.
To assess test-retest reliability, on receipt of their completed questionnaire, patients in the first three month period of recruitment were mailed a second, identical copy of the questionnaire to complete two weeks later.
All women were mailed a self-administered second questionnaire, on average 3.1 (s.d., 1.9) years after recruitment, that updated information on a range of measures, including new questions on diet, based on a food-frequency questionnaire, and intakes of various types of beverages.
At two week intervals, non-respondents were mailed a post-card reminder, a second mailing of the survey, and a final mailing of the survey via overnight mail (Federal Express).
