Validation of a susceptibility, benefits, and barrier scale for mammography screening among Peruvian women: a cross-sectional study

BACKGROUND Perceived beliefs about breast cancer and breast cancer screening are important predictors for mammography utilization. This study adapted and validated the Champion's scale in Peru. This scale measures perceived susceptibility for breast cancer and perceived benefits and barriers for mammography. METHODS A cross-sectional study was conducted among women ages 40 to 65 attending outpatient gynecology services in a public hospital in Peru. A group of experts developed and pre-tested a Spanish version of the Champion's scale to assess its comprehensibility (N=20). Factor analysis, internal consistency, and test-retest reliability analyses were performed (N=285). Concurrent validity compared scores from participants who had a mammogram and those who did not have it in the previous 15 months. T-test and multiple regression analysis adjusting for socio-demographic factors, mammography knowledge and other preventive behaviors were performed. RESULTS The construct validity and reliability were optimal. Cronbach-Alpha coefficients were 0.75 (susceptibility), 0.72 (benefits) and 0.86 (barriers). Concurrent validity analysis showed an association between barriers and mammography screening use in bivariate (22.3±6.7 vs. 30.2±7.6; p<0.001) and multiple regression analysis (OR=0.28, 95% CI=0.18-0.43). Ages 50-60 years (OR=2.35, 95% CI=1.19-4.65), history of prior Papanicolaou test (OR=3.69, 95% CI=1.84-7.40), and knowledge about breast cancer and mammography (OR=3.69, 95% CI=1.84-7.40) were also independently associated with mammography screening use. CONCLUSION Concurrent validity analysis showed that the Champion's scale has important limitations for assessing perceived susceptibility for breast cancer and perceived benefits for mammography among Peruvian women. There is still a need for developing valid and reliable instruments for measuring perceived beliefs about breast cancer and mammography screening among Peruvian women.