Health care workers test more young African-American and Hispanic women for chlamydia than white women. And this may inflate reported rates of this sexually transmitted infection (STI) among these population groups, according to a study published in the journal Pediatrics and reported by Medical News Today.

Researchers from Indiana University School of Medicine and the Regenstrief Institute examined data from more than 40,000 health care facility visits. They found that health workers were three times more likely to screen African-American women for chlamydia, and almost 10 times more likely to test Hispanic women for this STI compared with white women. (Additionally, after a pregnancy, health care workers were 24 times more likely to screen young Hispanic women and four times more likely to test African-American women for chlamydia than young white women.)

What’s more, findings showed two other factors besides race and ethnicity also determined the likelihood a women would be given chlamydia screenings: insurance status and age. Health care workers were more likely to administer chlamydia tests to women with public insurance compared with privately insured women. (And screening rate discrepancies between minorities and whites remained even after researchers accounted for different testing patterns among health care facilities.)

“This may mean that providers make judgments about a woman’s likelihood of infection based on her race or ethnicity,” said Sarah E. Wiehe, the study’s lead author and an assistant professor of pediatrics at the IU School of Medicine. “Yet in an asymptomatic condition like chlamydia, all sexually active young women should be screened.”

Only half of sexually active young women who receive health care get an annual screening. But the U.S. Preventive Services Task Force recommends yearly screenings for all sexually active young women ages 14 to 25.

Click here to learn why getting an annual chlamydia checkup is essential to your sexual health.