Abstract:
|
Methods and software to estimate health disparity indices (HDIs) and 95% confidence intervals (CI) for complex surveys are available (Cheng et al. 2008; US NCI HD*Calc 2009). Slope Index of Inequality (SII) is an often used HDI to assess health inequity among groups, such as socioeconomic position (SEP), along an ordered gradient. Since 2002, over 80 papers in PubMed reported SII to characterize an ordinal explanatory variable's relationship to health differences. We used the 2004-5 California Oral Health Needs Assessment of Children (total N=21,399 children) as a basis for initial simulations with a probit model and a fixed prevalence difference among SEP group levels. We varied overall disease prevalence (0.10-0.90), sample size (2156; 21,399; 42,798), and number of SEP groups (3,4,5,10) with 50 replicates and estimated SII. Varying sample size, by even 20 times more, affected SII CI width little. However, varying number of SEP groups had a dramatic effect: 3-4 groups had much wider CIs than 5-10 groups. Future health research should consider the number of SEP groups when using SII to measure health disparities. Support: UCSF Pilot Grant for King's College London Collaboration.
|
ASA Meetings Department
732 North Washington Street, Alexandria, VA 22314
(703) 684-1221 • meetings@amstat.org
Copyright © American Statistical Association.