Asking semi-literate adolescents about sexual behaviour: the validity of assisted self-completion questionnaire (ASCQ) data in rural Tanzania.

OBJECTIVES: To develop and test a sexual behaviour survey method for semi-literate populations, combining the privacy of a self-completion questionnaire (SCQ) with the clarity of a face-to-face questionnaire (FFQ). METHODS: In 1998, 6079 Tanzanian primary school students (mean age 15.1 years) were surveyed using an innovative assisted self-completion questionnaire (ASCQ). The format of the questionnaire was simple, all responses were closed, and conceptually complex questions such as those involving ranking or multiple answers were avoided. The ASCQ was administered to groups of 20 by a research assistant who read questions and answers aloud in two languages so pupils could tick or write responses independently. A total of 4958 of respondents from the 1998 ASCQ Cohort also participated in a 1998 FFQ interview and, in 2000, 4424 again completed an ASCQ. RESULTS: In the 1998 ASCQ survey, 55.0% of males and 21.1% of females reported they had had vaginal intercourse, of whom 71.5% and 66.0%, respectively reported their first sexual relationship lasted for a week or less, and 49.5% and 59.6%, respectively reported they had had sex in the last 4 weeks. After adjustment for age, reported sex was associated with alcohol use in both males (OR = 1.57) and females (OR = 1.69), earning money for males (OR = 1.32) and not living with a mother for females (OR = 0.77). The vast majority of respondents did not appear to have difficulty completing the ASCQ, but 7.4% of 1998 respondents and 2.9% of 2000 respondents selected all first or all last answers in a section for which this was inconsistent. This bias was associated with female, less educated and more geographically remote respondents. Of those respondents who reported sex in the 1998 ASCQ survey, 32.1% reported fewer total partners in the 2000 ASCQ survey, 25.2% reported having had sex fewer times than originally reported, and 61.9% of those who reported having used a condom in 1998 reported never having used one in 2000. While the proportions reporting sex were very similar in the 1998 ASCQ and FFQ surveys, 37.9% of males and 59.2% of females reporting sex only did so on one of the two questionnaires. Higher proportions of respondents reported sensitive information in the ASCQ than the FFQ, although in some cases this may have related to answer order bias. CONCLUSION: The results suggest that an ASCQ may be useful in assessing sexual behaviour in African adolescents, particularly for older, male and/or educated respondents. However, triangulation with data from other surveys raises questions about the validity of self-reported sexual behaviour in general.