Effect of computer-assisted self-interviews on reporting of sexual HIV risk behaviours in a general population sample: a methodological experiment.

OBJECTIVES

To develop methods to maximize the accuracy of reporting HIV risk behaviours in a general population survey. We assessed the feasibility of using a computer-assisted self-completion interview (CASI) in comparison with pen-and-paper self-completion interview (PAPI).

DESIGN

A probability sample survey of residents aged 16-44 years in Britain, with alternate assignment of addresses to interview by CASI (462) or PAPI (439).

METHODS

Personal interviews exploring demographic and sexual behaviour variables. Principal outcome measures were the impact of CASI in relation to PAPI on data quality and rates of reporting a range of behaviours.

RESULTS

A total of 901 interviews were completed; 829 individuals were eligible for and accepted the self-completion module. Internal consistency of data items was greater with CASI than PAPI and item non-response was lower. Overall, there was no significant difference in rates of reporting between CASI and PAPI. The main effect for CASI compared with PAPI in a generalized estimating equation (GEE) analysis was an OR (95% CI) of 1.04 (0.92-1.17). Variables were also examined individually, including homosexual partnership (adjusted OR 1.26 95%, CI 0.69-2.29), payment for sex (adjusted OR 0.68 95% CI 0.29-1.59), masturbation (adjusted OR 0.89 95% CI 0.66 1.22) and five or more partners in the past 5 years (OR 0.85 95% CI 0.61 -1.19).

CONCLUSION

We found no evidence of a consistent effect of CASI on rates of reporting sexual HIV risk behaviours in this sample. CASI resulted in improvement in internal consistency and a reduction in missed questions.