P5-09-03: Health Literacy Affects Use of Screening Mammography in an Underinsured Population.
Authors: Komenaka IK , Nodora J , Hsu C-H , Machado L , Klemens AE , Zenuk R , Bouton ME , Martinez ME , Weiss BD 
Published: June 2012

Background: In late 2009 significant controversy arose when some screening recommendations were changed to advocate screening mammography starting at age 50 rather than the long standing recommendation of starting at age 40 years. Few would argue, by contrast, that patient compliance with screening mammography, starting at either 40 years or 50 years, is at optimal levels. National data indicate that many more lives would be saved by improving compliance with screening recommendations in individuals ≥50 than would be saved with screening individuals age 40–50 years. The current study was performed to determine if health literacy was associated with use of screening mammography in an underinsured population.

Methods: Maricopa Medical Center is the county safety net hospital in Phoenix, Arizona. 944 patients were seen at the Breast Clinic from January 2010 to January 2011. 638 were at least 40 years old and therefore candidates for screening mammography. Sociodemographic variables were collected. Use of mammography was asked of patients and checked by medical records. Health literacy was assessed using the Newest Vital Sign (NVS) validated screening instrument, which categorizes health literacy on 6-point scale as low health literacy likely (0-1 point), low health literacy possible (2-3 points), or health literacy adequate (4-6 points). Differences in patient characteristics were evaluated based on a Fisher's exact test for categorical variables and one-way ANOVA for continuous variables. Multivariate analysis was then performed to determine which patient factors were associated with use of screening mammography.

Results: Among women 40 years or older, only 35% used routine screening mammography. For women 50 years or older, 38% underwent screening mammography. Among women 40 years or older and those 50 years or older, significantly more with health literacy adequate (NVS 4–6) obtained screening mammography than did women in the two lower literacy (NVS 0–1 and 2–3) groups (40+: 65% vs. 30% and 30%, p = 0.001. 50+: 65% vs. 33% and 37%, p = 0.001). Multivariate analyses adjusted for insurance status, employment, white race, Hispanic ethnicity, marital status, language, use of alcohol, family history, NVS and education level demonstrated that patients with adequate health literacy were more likely to use screening mammography (OR 3.66; 95% CI 2.14 — 6.27; p &lt; 0.01) than patients in the two lower literacy groups. Similarly, uninsured patients were significantly less likely to undergo screening mammography (OR 0.57; 95% CI 0.38 — 0.86; p = 0.01) than those with insurance. Patients with adequate health literacy and insurance were (OR 8.61) more likely to use screening mammography than patients who were uninsured and were in the two low literacy groups. Patient race, ethnicity, language, employment, income, education level, and family history of breast cancer were not associated with use of screening mammography in this underinsured, undereducated population.

Conclusions: Use of screening mammography was poor in this underinsured population. Limited health literacy and lack of insurance are risk factors for failure to obtain mammography. Interventions to increase use of screening mammography among uninsured patients with limited health literacy are needed.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-09-03.