Development of a Health Disparities Index: Proof of Concept with Chest Radiography in Asthma

Abstract

To develop a tool for quantifying health disparity (Health Disparity Index[HDI]) and explore hospital variation measured by this index using chest radiography (CXR) in asthma as the proof of concept. This was a retrospective cohort study using the Pediatric Health Information System database including children with asthma between 5 and 18years old. Inpatient and emergency department (ED) encounters from January 1, 2017, to December 31, 2018, with low or moderate severity were included. Exclusions included hospitals with <10 cases in any racial/ethnic group. The HDI measured variation in CXR use among children with asthma based on race/ethnicity. The HDI was calculated as the absolute difference between maximum and minimum percentages of CXR use (range=0-100) when there was statistical evidence that the percentages were different. Data from 36 hospitals included 16 744 inpatient and 75 805 ED encounters. Overall, 19.7% of encounters had a CXR (34.3% for inpatient; 16.5% for ED). In inpatient encounters, 47.2% (17/36) of hospitals had a significant difference in imaging across racial/ethnic groups. Of these, the median hospital-level HDI was 19.4% (IQR 13.5-20.1). In ED encounters, 78.8% (28/36) of hospitals had a statistically significant difference in imaging across racial/ethnic groups, with a median hospital-level HDI of 10.2% (IQR 8.3-14.1). There was no significant association between the inpatient HDI and ED HDI (P=.46). The HDI provides a practical measure of disparity. To improve equity in healthcare, metrics are needed that are intuitive, accurate, usable, and actionable. Next steps include application of this index to other conditions.