Objectives: The aim of this study was to identify the determinants of single heterosexuals' use of condoms during each sexual intercourse.
Design: Cohort of individuals followed over a period of 2 years.
Methods: Respondents were 574 single heterosexual individuals who answered questions during a telephone interview.
Results: Attitude, perceived behavioural control, self-efficacy and moral norm explained 65% of the variance in intentions to use condoms ( p, .0001). The determinants of condom use at 1 year follow-up (27% explained variance) were perceived behavioural control, past behaviour, and the interaction between intention and intention stability. At 2 years follow-up, the significant determinants were past behaviour and intention by intention stability. In the present study, intentions to use condoms which remained stable across time were strong predictors of condom use (at 1 year: beta = .42, p < .0001; at 2 years: beta = .39, p, < .003), while unstable intentions were not (at 1 year: beta = .02, ns; at 2 years: beta = .19, ns).
Conclusion: Intention stability is a major determinant of the accuracy of intention for the prediction of subsequent behaviour.