Abstract B35: Disparities in follow up after abnormal mammogram for multiple Asian subpopulations
Authors: Nguyen Kim Hanh , Karliner Leah , Pasick Rena 
Published: October 2015

Introduction: The burden of breast cancer among certain Asian subpopulations is higher than previously estimated, underscoring the need for close scrutiny of Asian disparities across the breast cancer continuum from prevention through survivorship. A critical point in this process, timely and complete follow-up of screening abnormalities, is known to be inadequate among women in minority groups but has not yet been studied among disaggregated Asian populations. The objective of this investigation was to assess and compare the timeliness in follow-up after abnormal mammogram among White and Asian American women in the San Francisco Bay Area.

Methods: Using data from the San Francisco Mammography Registry (SFMR), we identified women with an index abnormal screening mammogram result of BIRADS 0/3+ between the years 2000-2010. Our study sample included women who self-report White or Asian race/ ethnicity, ages 30 and older who received screening services at 10 participating SFMR-facilities. We first used chi-square statistics to compare median days to diagnostic follow-up after abnormal mammogram by patient characteristics including race/ethnicity. Cumulative percent plots were constructed to visually display the percentage of racial/ethnic groups with follow-up at multiple time intervals (i.e., 30 days, 60 days). We then conducted hierarchical regression analyses that adjust for the multilevel nature of the data, controlling for within-facility clustering of observations, estimating the associations between follow-up and sociodemographic characteristics including age and education, as well as family history of breast cancer. Subgroup comparisons identified differences in these factors which might explain abnormal mammogram follow-up disparities.

Results: The total sample was 54,028 women, 70% White and 30% Asian. Among Asians, 16.2% were Chinese, 6.7% Filipina, 1.8% Japanese, 1.1% Vietnamese, 2.4% Other Asian, and 1.4% Mixed Asian. The mean age of women was 53.4 years, and the majority fell within the range of 40-74 years recommended for screening. The proportion of women who did not receive follow-up within one year after an index abnormal mammogram was 11.1% (n=6023). A higher proportion of Asian women did not receive follow-up compared to Whites (15% vs 10%). Among Asian groups, Filipinas had the highest percentage of women not receiving follow-up (18%) while Japanese women had the lowest (10.4%). In comparing those who received follow-up and those who did not, a higher proportion of women with no follow-up had lower education levels (24% vs 15%). Median time to diagnostic follow-up for White and Asian women combined was 18 days. The median follow-up time was 15 days for Whites and 26 days for Asians. The median follow-up time differed significantly among Asian ethnic groups: Japanese women had the shortest (19 days) followed by Filipinas (28 days). Vietnamese women had the longest (30 days).

Hierarchical regression model results with Whites and Asians, accounting for sociodemographic variables and the effect of facility, indicate that women who did not complete high school and Asian women had higher odds of no follow-up after an abnormal mammogram at 30, 60, and 90 days compared to women with a graduate degree and Whites, respectively OR 1.3, CI: 1.16-1.41, and OR 1.2, CI: 1.14-1.27. Race was no longer significant at 60 and 90 days. For regression analyses comparing Whites and Asians by ethnicity, controlling for facility, Chinese, Filipina, Other Asian and Mixed Asian were more likely than White women to not receive follow-up, even after accounting for facilities at 30 days. At 60 days, only Filipinas were significantly more likely to receive no follow-up. At 90 days, Filipina women had slightly higher odds of no follow-up compared to Whites (OR 1.1, CI: 1.02-1.28).

Conclusion: We observed disparities in timeliness to follow-up between White and Asian women and among Asian ethnic groups in the first 30-days after an abnormal screening mammogram. Disaggregation of ethnicity can identify subpopulations most in need of breast cancer control, and to provide more specific information on care delivery patterns.

Citation Format: Kim Hanh Nguyen, Leah Karliner, Rena Pasick. Disparities in follow up after abnormal mammogram for multiple Asian subpopulations. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr B35.