Introduction: Breast cancer is the second leading cause of cancer death among women in the United States. Although mammography screening is supported by the U.S. Preventive Services Task Force and has been found to effectively reduce mortality, only about 65% of women over 40 years of age are adherent to mammography screening guidelines, a rate far below the 81.1% goal proposed for Healthy People 2020. Screening rates are even lower among smokers compared to non-smokers; however, the reasons for this disparity remain unclear. Overall, knowledge, barriers, benefits, self-efficacy, and perceived risk play a role in decision making and may influence cancer screening behavior. Therefore, the purpose of this study was to examine the association between smoking status and mammography adherence, and to determine whether differences in knowledge, barriers, benefits, self-efficacy, and perceived risk could account for screening disparities between smokers and non-smokers.
Methods: A prospective, randomized screening intervention of women aged 50-75 (n=1,196) was conducted in Indiana from 2013-2015. A total of 846 women had complete smoking and mammography data for use in this analysis. Women were surveyed at baseline to ascertain current smoking status and mammography history, as well as knowledge, barriers, self-efficacy, benefits, and perceived risks for mammography. Binary logistic regression was used to estimate multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between smoking and mammography adherence. T-tests were used to evaluate differences between current smokers and non-smokers with regard to knowledge, barriers, benefits, self-efficacy, and perceived risk. Regression analyses were adjusted for age, education, income, insurance coverage, ever receiving a physician recommendation for mammography, and family history of breast cancer.
Results: Smokers were significantly younger, less educated, and had lower income relative to non-smokers. Smokers were less likely to be adherent to mammography screening relative to non-smokers [OR = 0.54 (0.32 - 0.90), p=0.020)]. Smokers also demonstrated significantly less knowledge of breast cancer and mammography (p=0.0016), reported more barriers to screening (p=0.020), had less self-efficacy (p=0.0018), and had a lower perceived risk of breast cancer (p=<0.0001) compared with non-smokers. No differences were observed for benefits to screening (p=0.81).
Conclusions: Women who smoke are less likely to adhere to mammography screening guidelines than non-smokers, possibly due to less knowledge about breast cancer and mammography, more barriers to screening, less self-efficacy, and less perceived risk. Future interventions to increase mammography should consider smoking status disparities and tailor intervention content accordingly.
Citation Format: Andrew R. Marley, Lisa Carter-Harris, Wambui Gathirua-Mwangi, Victoria L. Champion. Smoking and mammography screening: An analysis of knowledge, barriers, self-efficacy, benefits, and perceived risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2424.