Breast self-examination: longitudinal predictors of intention and subsequent behaviour.

This study analysed in a longitudinal design the relationship between past breast self-examination (BSE) behaviour, determinants, intention and future BSE behaviour in a population of adult Dutch women. Past behaviour and psychosocial determinants were assessed at T1, followed 6 weeks later (T2) with the assessment of the intention to perform BSE monthly. Half a year after the first measurement the current BSE behaviour was assessed by means of a telephone survey (T3) (total end response 78%, n=364). The questionnaires included BSE behaviour, intention, attitude (pros and cons of BSE, anticipated regret, moral obligation), social influence (support, modelling) and self-efficacy. Other background variables assessed were past BSE behaviour, and demographics. Although 81% of the women stated that they performed BSE, only 41% of the women performed BSE correctly. Women who performed BSE correctly differed from women who did not on all psychosocial determinants assessed a half year earlier, with the exception of anticipated regret. Stepwise multiple regression analyses showed that the psychosocial determinants explained 51% of the variance in intention to perform BSE, assessed 6 weeks later; past behaviour accounted for 2% of extra explained variance. Logistic regression analyses showed that past behaviour, the psychosocial determinants and intention were significant predictors of correct BSE behaviour a half year later (Nagelkerke's total explained variance was 47%). It was concluded that misperceptions of correct BSE behaviour was highly prevalent. Both the psychosocial determinants as well as past behaviour were important predictors of intention to perform BSE and subsequent BSE behaviour.