Objective In order to determine if easy–difficult item measures attitude or perceived behavioural control (PBC), we used structural equation modelling of 10 cross-sectional data sets.
Design Cross-sectional design was used.
Method. Ten studies that examined health-related behaviours and used the theory of planned behaviour as a theoretical framework were analysed. Samples totalling N = 4,552 participants were employed. All studies involved multi-item measures of attitude (Aact) and PBC items derived from pilot testing.
Results Confirmatory factor analysis confirmed the discriminant validity of Aact and PBC. Structural equation modelling of relevant path indicated that in three studies, easy–difficult item is an indicator of both Aact and PBC. In the other seven studies, easy–difficult item belongs to PBC. The indexes of meta-analysis suggest that overall, easy–difficult item is an indicator of PBC.
Conclusion. Findings from 10 studies converged toward the conclusion that the easy–difficult item is an indicator of perceived PBC. However, since the easy–difficult item is sometimes classified as both Aact and PBC, and only the perceived difficulty dimension of PBC captures a significant increment in the variance of intention, it appears important to develop and validate a set of items devoted to measure the perceived difficulty dimension adequately.