Stepwise Proportional Weighting Algorithm for Single-Race Population Estimation Using Hawai'i Census Data.

Many health and health disparities studies require population prevalence information of various race groups, but the estimation of single-race population sizes using the US Census data has been challenging. For each Census race group, Census only provides the counts of those reported being single race ("race alone") and those reported of that specific race regardless of whether the individuals were multiracial or not ("race alone or in (any) combination"). The issue of how to classify Census multiracial individuals is especially important for the state of Hawai'i due to its large multiracial population. The current study developed the Stepwise Proportional Weighting Algorithm (SPWA) for single-race population estimation using US Census data for major race groups in the Census and their nested detailed races. Additionally, given that "partial Native Hawaiian" has often been treated as "Native Hawaiian" in health disparities studies in Hawai'i, the algorithm can also adjust for the unique partial Native Hawaiian race categorization. This paper describes the estimation process with the SPWA and demonstrates its ability to estimate single-races for the 5 most common race groups in Hawai'i. This new methodology addresses an important concern regarding how to classify multiracial individuals to strengthen health and health disparities research in Hawai'i.

Age and Sex Distributions of 31 Common Racial Groups in Hawai'i: A Shiny Web Application.

Hawai'i is the most ethnically diverse state with the highest proportion of multiracial individuals in the United States. The Stepwise Proportional Weighting Algorithm (SPWA) was developed to bridge the categorization of multiracial Census data into single-race population estimates for common races in Hawai'i. However, these estimates have not been publicly available. A Shiny web application, the Hawai'i Single-Race Categorization Tool, was developed as a user friendly research tool to obtain the age and sex distributions of single-race estimates for common racial groups in Hawai'i. The Categorization Tool implements the SPWA and presents the results in tabular and graphic formats, stratified by sex and age. It also allows the categorization of partial Native Hawaiians as Native Hawaiians in the population estimation. Using this tool, the current paper reports population estimates and distributions for 31 common racial groups using Hawai'i Census 2010 data. Among the major Census races, Asian had the largest population (631 881; 46.5%) in Hawai'i, followed by White (431 635; 31.7%) and Native Hawaiian and Other Pacific Islander (227 588; 16.7%). Among Census detailed races within Asian, Filipino had the largest population estimate (244 730; 18.0%), followed by Japanese (227 165; 16.7%) and Chinese (103 600; 7.6%). Native Hawaiian accounted for 12.3% of the Hawai'i population (166 944). After recategorizing part-Native Hawaiians as Native Hawaiians, Native Hawaiian increased by 150.0%, with the greatest increase among the young. This publicly available tool would be valuable for race-related resource allocation, policy development, and health disparities research in Hawai'i.