Psychosocial influences on older adults' interest in participating in bowel cancer screening

As part of a multicenter, randomized controlled trial of the efficacy of flexible sigmoidoscopy for the prevention of bowel cancer, an investigation of the predictors of screening interest was carried out in a subsample of older adults.

The aim of the study was to establish the predictive power of the Health Belief Model (HBM) and to evaluate the contribution of HBM elements in mediating the effect of other demographic and health variables which have been found to be associated with screening interest and participation. A total of 5,099 participants were sent a postal questionnaire which examined screening interest, attitudes toward screen ing (benefits and barriers), perceived bowel cancer risk, bowel cancer worry, bowel symptoms, health status, state anxiety, and optimism. A total of 3,648 questionnaires were returned completed, giving a response rate of 71.5%.

The results showed that threat, barriers, and benefits explained 47% of the variance in interest. Demographic and health variables were also associated with screening interest, although most of their effect was mediated by the HBM constructs.

This community study in older adults showed a high level of interest in participating in screening. The large sample size provided the opportunity to test the value of the HBM model and to examine mediation of demographic and health variables. The HBM proved to be a good model of screening interest. These results further our understanding of the decision processes in participating in cancer screening and point to directions to increase the level of participation in community samples.