HIV-protection through condom use: Testing the theory of planned behaviour in a community sample of heterosexual men in a high-income country

Abstract

Given the increasing importance of heterosexual HIV-transmission in Europe and Switzerland, the present study tested the theory of planned behaviour (TPB) in a prospective study on the HIV-protection behaviour in a community sample of heterosexual men. The study focused on condom use in sexual encounters with new partners. Participants were 982 Swiss men between the ages of 25 and 65 who were surveyed using standardised questionnaires in two computer-assisted telephone interviews that took place in autumn 2002 and spring 2003. The TPB was able to predict condom use in sexual encounters with new and casual partners. In accordance with the theory, condom use was predicted by intention. Perceived behavioural control and attitude were significant predictors of intention, whereas subjective norm was not. Thus, in line with other studies, the present study highlighted the somewhat limited explanatory power of the theory. Further theoretical and empirical work is needed to develop extensions to the theory.

Keywords:

• Socio-cognitive models
• theory of planned behaviour
• HIV-protection behaviour
• HIV/AIDS
• heterosexual men

Acknowledgements

We acknowledged the referred study at the University of Applied Sciences Aargau Northwestern Switzerland, Department Social Work from October 2001 till October 2003. The study was sponsored by the Swiss National Science Foundation. Thanks are also due to the Swiss Aids Federation and Professor Dr Reinhard Fatke, Institute of Pedagogic at the University of Zurich for their support.

Notes

Notes

[1] The situation in question is the first sexual encounter with a person, with whom the man has not been intimate before. This can turn out to be the first intercourse of a longer relationship or to be a casual sexual encounter.

[2] This is a translation of the original German formulation.

[3] As rating technique, we used an unipolar 11-point-scale ranging from 0 to 10. This type of scale is often called a “number production scale”. As a rule, the rating scales usually employed in attitude research constitute a variety of the Likert scale, with verbally labelled response categories ranging from “not at all” to “completely”, and with either an even or an uneven number of possible responses. In order to be able to treat such an ordinal scale as a numerical scale, it is best to offer response scales with a greater number of categories. On the other hand, a number of (e.g., seven) verbal categories might make it difficult for respondents to understand the content of the categories and the differences between them. Such a gradation is therefore not very useful. At the same time, various studies have shown that it is the number of response categories or scale points that has the strongest influence on the quality of the data (Alwin & Krosnick, 1991; Andrews, 1984; Költringer, 1993; Rodgers, Andrews, & Herzog, 1992). Thus, the rule is: the more categories, the higher the validity and reliability of the scales and the fewer the random errors. Number production scales are to be preferred to verbally labelled response categories (Andrews, 1984). Number production scales have the added advantage of saving time during the interview, since the interviewer only has to read out the end figures of the scale over the telephone. Moreover, with CATI number production scales are easy to handle (House & Nicholls II, 1988). Furthermore, number production scales prevent response-order effects, such as primacy or recency effects (Scherpenzeel, 2002).