Poverty Gradients and Racial/Ethnic Analysis of Gonorrhea in California Michael C. Samuel, DrPH; Yuri Springer, PhD; Denise Gilson; Gail Bolan, MD STD Control Branch California Department of Public Health 2008 National STD Prevention Conference Confronting Challenges, Applying Solutions Chicago, Illinois, March 10-13, 2008

Background Dramatic variation in STD rates among racial/ethnic groups STD rates inversely related to socioeconomic status Surveillance data generally do not include socioeconomic status data Differentials in STD rates by race/ethnic group not statistically “accounted for” by differentials in socioeconomic status

Background Project Questions: How does the relationship between STD rates and socioeconomic status vary among different racial/ethnic groups in California? How do these relationships vary geographically?

“Area Based Socioeconomic Measures” (ABSM)” Methods - Data STD data 2004 to 2006 gonorrhea cases in California Provider/laboratory case reports Generally includes address of case “Area Based Socioeconomic Measures” (ABSM)” Determine case census tract based on case address Multi-tiered process of cleaning and geocoding case address Associate 2000 US Census tract “percent living below federal poverty level” with each case in that census tract Group poverty into four levels: <10%, 10-20%, 20-30%, >30%

Methods - Analyses Rate calculation Results visualization GC rates in each census tract for each racial/ethnic groups (Asians, African Americans, Hispanics, Whites) Numerator: # of cases (weighted to account missing race/ethnicity data) Denominator: Corresponding 2000 US Census Bureau population counts for each census tract Results visualization Plot relationships between poverty and infection by race/ethnicity Map spatial distribution of cases Rates aggregated across full state and for individual counties

Results Address Category and Geocode Status California Gonorrhea Cases – 2004-2006 Address Category . Cases Percent Total 98,355 100.0% Blank 9,501 9.7% Incomplete 2,442 2.5% Non-resident address 1,507 1.5% Other 421 0.4% P.O. Box 1,337 1.4% Potentially Geocodable 83,147 84.5% Successfully Geocoded 79,100 80.4%

Results Geocode Status by Race/Ethnic Category Total % of Total California Gonorrhea Cases – 2004-2006 Total % of Total Race/Ethnicity cases cases geocoded Asian 2,348 86.3 African American 25,704 89.3 Hispanic 20,290 86.5 White 17,116 84.7 Unknown 31,959 66.7

Results Socioeconomic Gradients in Infection Rates by Race/Ethnicity California Gonorrhea Cases, 2004-2006

Results Socioeconomic Gradients in Infection Rates by Race/Ethnicity Selected Counties - California Gonorrhea Cases, 2004-2006 Los Angeles San Diego San Francisco Sacramento

Results Census Tract Poverty Levels California 2000 US Census Data 3,259 (46%) 1,975 (28%) 986 (14%) 721 (10%) 108 (2%) . 7,049 Percent Below Poverty . # Tracts .

Results Spatial Clustering of Cases by Poverty Level Poverty <10% N=19,135 cases 24% of all cases (46% of all tracts) Poverty 10-20% N=23,784 cases 30% of all cases (28% of all tracts) Poverty 20-30% N=16,876 cases 21% of all cases (14% of all tracts) Poverty >30% N=18,968 cases 24% of all cases (10% of all tracts)

Results Spatial Clustering of African American Cases by Poverty Level 13% of Af. Am. cases (46% of all tracts) Poverty 10-20% N=5,771 cases 25% of Af. Am. Cases (28% of all tracts) Poverty 20-30% N=5,729 25% of Af. Am. Cases (14% of all tracts) Poverty >30% N=8,471 cases 37% of Af. Am. Cases (10% of all tracts) 11% of all cases

Results Case Density by and Poverty and Race/Ethnicity

Conclusions - Findings Racial/Ethnic Trends Pronounced variation in GC infection rates among racial/ethnic groups Rates among African Americans 9-14 times higher than Whites Poverty Gradients Infection rates increase with increasing levels of neighborhood poverty Rates for African Americans in even the wealthiest neighborhoods are higher than rates for any other race/ethnic group in any poverty level, including the poorest neighborhoods Spatial Clustering of Cases Poorest census tract represent only 10% of the state’s total tracts but contain ~25% of GC cases and ~37% of African American GC cases

Conclusions - Limitations Use of ABSMs to estimate case-specific information Use of year-2000 census data to calculate rates Method of weighting for missing race/ethnicity data Over 15% of cases could not be geocoded and were not included in our analyses

Conclusions – Implications/Recommendations Targeted prevention efforts in neighborhood “hot spots” could reach large numbers of cases, particularly among African Americans Screening programs? Prevention outreach? Social marketing? Network interventions should be explored, since these findings suggest transmission in dense networks Any/all efforts in this area need to be led at local level and incorporate input of affected populations

Contact Information: Michael C. Samuel, DrPH STD Control Branch California Dept. of Public Health 850 Marina Bay Parkway, Richmond, CA 94804 Michael.Samuel@cdph.ca.gov 510.620.3198 Acknowledgements Alameda County Dept. of Public Health Matt Beyers Jane Martin Los Angeles County Dept. of Public Health Kai-Jen Cheng San Francisco County Dept. of Public Health Robert Kohn