Chlamydia positivity in women screened in family planning clinics: racial/ethnic differences and trends in the northwest U.S., 1997-2006

Public Health Rep. 2012 Jan-Feb;127(1):38-51. doi: 10.1177/003335491212700105.


Objectives: We assessed chlamydia trends, individual-level risk factors, and population-level area-based socioeconomic measures (ABSMs) associated with chlamydia infection in women attending U.S. Public Health Service (PHS) Region X Infertility Prevention Project (IPP) family planning (FP) clinics from 1997-2006. We then explored these measures within racial/ethnic subpopulations.

Methods: Using data from 667,223 chlamydia tests obtained from women aged 15-24 years screened in 201 FP clinics, we employed a generalized mixed model with logistic link, incorporating clinic and ZIP code as random effects to adjust for risk of chlamydia associated with individual- and population-level (areal) measures for the overall population and for each racial/ethnic subpopulation.

Results: Significant racial/ethnic differences in chlamydia persisted after adjusting for individual and aggregate factors. Relatively steep chlamydia gradients were found across racial/ethnic ABSM levels. Compared with white women, infection risk was significantly higher for black (adjusted odds ratio [AOR] = 1.93), American Indian/Alaska Native (AOR=1.62), Asian/Pacific Islander (AOR=1.42), and Hispanic (AOR=1.28) women. The impact of population-level ABSMs on chlamydia varied across racial/ethnic groups and was generally modest. Among white women, there was a significant 4% relative annual increase in predicted chlamydia during the 10-year period 1997-2006. Chlamydia positivity over time did not change for racial/ethnic minority groups after adjusting for individual- and population-level factors.

Conclusions: Racial/ethnic differences in chlamydia persisted over time and were not mitigated by adjustment for aggregate socioeconomic position or areal racial/ethnic measures. Changes in project strategies will be needed to address racial/ethnic disparities for chlamydial infection among young female FP clinic clients.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Asian / statistics & numerical data
  • Black or African American / statistics & numerical data
  • Chlamydia Infections / diagnosis*
  • Chlamydia Infections / ethnology*
  • Chlamydia trachomatis / isolation & purification*
  • Ethnicity
  • Family Planning Services / statistics & numerical data*
  • Female
  • Hispanic or Latino / statistics & numerical data
  • Humans
  • Indians, North American / statistics & numerical data
  • Inuit / statistics & numerical data
  • Northwestern United States / epidemiology
  • Risk Factors
  • Socioeconomic Factors
  • White People / statistics & numerical data
  • Young Adult