Using cluster analysis to explore heart age among cancer survivors in Alabama.

Introduction: More than 223,000 cancer survivors reside in Alabama. The five-year survival rate of all cancer survivors is approximately 67%. Cancer treatment and behavioral risk factors may contribute to increased cardiovascular disease risk among cancer survivors. Heart age estimates cardiovascular disease risk using chronologic age, systolic blood pressure, smoking status, diabetes status, antihypertensive use, height, and weight. The purpose of this poster is to explore heart age in Alabama using cluster analysis. Methods: Data were from the CDC-established Behavioral Risk Factor Surveillance System using Alabama years 2011 and 2013. Records were included if between ages 30-74 years. Cluster analysis uses a k-means clustering algorithm to fit the data. The first step is to identify optimal number of clusters based on similar properties (e.g., chronologic age, heart age, and body mass index) using the plot within cluster error. The second step is to assess the plot using the “elbow method” by selecting the optimal number of clusters based on the “elbow.” SAS 9.4, SUDAAN 11.0.1, and RStudio 3.2.3 were used to conduct statistical analyses. Results: Four clusters were identified. Cluster 1 (n = 2,523) comprised older participants (66 years), who had a higher heart age (86 years) and overweight body mass index (28). Cluster 1 included 50% of the cancer survivor participants. Cluster 2 (n = 2,088) and Cluster 3 (n = 2,405) were younger (means of 39 and 55) with a lower excess heart age (means of 2 and 6) and overweight body mass index (28 and 25). Cluster 4 (n = 1,137) participants were middle-aged (mean 54 years), mean excess heart age of 22 years, morbidly obese, 42% non-Hispanic Blacks, and high self-report rate of diabetes (33%). Discussion: Cluster analysis provides for additional data not found through mean comparison tests. Obesity is not a sole factor in increased cardiovascular disease risk among cancer survivors. Cancer treatment, not accounted for in heart age calculations, may contribute to risk. Additionally, middle-aged Alabama residents in Cluster 4 may be at risk for both cancer and cardiovascular disease. Future considerations may include creating a cancer-specific heart age tool. Citation Format: Jacqueline B. Vo, Dheeraj Raju, Karen Meneses. Using cluster analysis to explore heart age among cancer survivors in Alabama [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A10.