OBJECTIVE: To validate two versions of a short self-completion questionnaire on time-to-pregnancy. DESIGN: Information from the questionnaire was compared with concurrently collected data from the same individuals. POPULATION: Questionnaires were sent to 1,647 women who continue to be followed up by the Oxford Family Planning Association Contraceptive Study. Replies were received from 1,498, a response rate of 91.0%. Successful matching was achieved with 1,392 pregnancies that met the study criteria and that had values of time-to-pregnancy in both data sources. Median recall time was 14 years (interquartile range, 11 to 16 years). MAIN OUTCOME MEASURES: At the group level, the frequency distributions of time-to-pregnancy from the two sources are presented as cumulative percentages. At the individual level, the distribution of discrepancies between the sources is tabulated separately for each value of time-to-pregnancy, and accuracy of detection of clinical subfertility is presented (sensitivity and specificity). RESULTS: At the group level, remarkably good agreement was found between the two sources of information. Digit preference was present to a limited degree. There were no important differences between the two questionnaire versions. At the individual level, some misclassification was evident. For the detection of clinical infertility, sensitivity was 79.9% and specificity was 94.9%. CONCLUSIONS: Short, self-completion questionnaires are remarkably accurate for assessing time-to-pregnancy at a group level. Individual-level misclassification is frequent, but detection of clinical subfertility is fairly accurate.
OBJECTIVE: To validate two versions of a short self-completion questionnaire on time-to-pregnancy. DESIGN: Information from the questionnaire was compared with concurrently collected data from the same individuals. POPULATION: Questionnaires were sent to 1,647 women who continue to be followed up by the Oxford Family Planning Association Contraceptive Study. Replies were received from 1,498, a response rate of 91.0%. Successful matching was achieved with 1,392 pregnancies that met the study criteria and that had values of time-to-pregnancy in both data sources. Median recall time was 14 years (interquartile range, 11 to 16 years). MAIN OUTCOME MEASURES: At the group level, the frequency distributions of time-to-pregnancy from the two sources are presented as cumulative percentages. At the individual level, the distribution of discrepancies between the sources is tabulated separately for each value of time-to-pregnancy, and accuracy of detection of clinical subfertility is presented (sensitivity and specificity). RESULTS: At the group level, remarkably good agreement was found between the two sources of information. Digit preference was present to a limited degree. There were no important differences between the two questionnaire versions. At the individual level, some misclassification was evident. For the detection of clinical infertility, sensitivity was 79.9% and specificity was 94.9%. CONCLUSIONS: Short, self-completion questionnaires are remarkably accurate for assessing time-to-pregnancy at a group level. Individual-level misclassification is frequent, but detection of clinical subfertility is fairly accurate.
Authors: M Joffe; L Bisanti; P Apostoli; P Kiss; A Dale; N Roeleveld; M-L Lindbohm; M Sallmén; M Vanhoorne; J P Bonde Journal: Occup Environ Med Date: 2003-10 Impact factor: 4.402
Authors: M Sallmén; M L Lindbohm; A Anttila; P Kyyrönen; H Taskinen; E Nykyri; K Hemminki Journal: Occup Environ Med Date: 1998-01 Impact factor: 4.402
Authors: Maureen A Cooney; Germaine M Buck Louis; Rajeshwari Sundaram; Bridget M McGuiness; Courtney D Lynch Journal: Epidemiology Date: 2009-01 Impact factor: 4.822