Validation of a measurement tool to assess awareness of breast cancer.
Linsell L., Forbes LJ., Burgess C., Kapari M., Thurnham A., Ramirez AJ.
AIM: Until now, there has been no universally accepted and validated measure of breast cancer awareness. This study aimed to validate the new Breast Cancer Awareness Measure (BCAM) which assesses, using a self-complete questionnaire, knowledge of breast cancer symptoms and age-related risk, and frequency of breast checking. METHODS: We measured the psychometric properties of the BCAM in 1035 women attending the NHS Breast Screening Programme: acceptability was assessed using a feedback questionnaire (n=292); sensitivity to change after an intervention promoting breast cancer awareness (n=576), and test-retest reliability (n=167). We also assessed readability, and construct validity using the 'known-groups' method. RESULTS: The readability of the BCAM was high. Over 90% of women found it acceptable. The BCAM was sensitive to change: there was an increase in the proportion of women obtaining the full score for breast cancer awareness one month after receiving the intervention promoting breast cancer awareness; this was greater among those who received a more intensive version (less intensive version (booklet): 9.3%, 95% confidence interval (CI): 4.5-14.1%; more intensive version (interaction with health professional plus booklet): 30%, 95% CI: 23.4-36.6%). Test-retest reliability of the BCAM was moderate to good for most items. Cancer experts had higher levels of cancer awareness than non-medical academics (50% versus 6%, p=0.001), indicating good construct validity. CONCLUSIONS: The BCAM is a valid and robust measure of breast cancer awareness suitable for use in surveys of breast cancer awareness in the general population and to evaluate the impact of awareness-raising interventions.