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Pay attention to age in chlamydia screening
What is your practice when it comes to screening women for chlamydia? The Centers for Disease Control and Prevention (CDC) recommends annual chlamydia screening for all sexually active young women age 25 and younger.1
However, when it comes to screening women above age 25, the CDC recommends against routine screening unless the individuals are at increased risk of infection from the sexually transmitted disease (STD). What constitutes an increased risk? Look for a history of sexually transmitted infections, new or multiple sex partners, inconsistent condom use, or the practice of exchanging sex for money or drugs.1
Many clinicians might not be following national guidance on age-based screening when it comes to chlamydia. In 2008, 2,325,980 women were screened for chlamydia in Title X clinics; of that number, 890,550 were age 25 and above.2 It is highly unlikely that all of these women were tested due to a risk factor, according to a recent editorial on the subject.3
Because younger women are at increased risk for chlamydia compared to older women, screening them is more likely to result in finding disease, says Susan Philip, MD, MPH, director of the San Francisco STD Prevention and Control Services for the San Francisco Department of Public Health. Officials with that department have implemented a structural intervention aimed at reducing chlamydia screening among females over age 25 at sites in the San Francisco STD Screening Program. An analysis of the intervention indicates it resulted in a 24.4% reduction in test volume and an associated cost savings of nearly $40,000 in its first year of implementation.4
"We really want to make sure we are focusing our resources on testing this very high risk population of young women," says Philip.
Putting emphasis on screening young women for chlamydia is effort well spent. Chlamydia screening among young women has been recognized by the National Commission on Prevention Priorities as one of the most beneficial and cost-effective preventive services among all evidence-based clinical preventive services recommended by the United States Preventive Services Task Force.5
How did they do it?
Prior to its intervention, officials in the San Francisco STD Prevention and Control Services office had worked with the test sites to educate clinicians on the importance of screening women ages 25 and under for chlamydia, says Kyle Bernstein, PhD, ScM, chief of epidemiology, research, and surveillance within the STD Prevention and Control Services office. However, the message was not being received: 64% of tests submitted to the San Francisco Public Health Laboratory in 2008 were among women age 26 and above.
To implement the intervention, the STD Prevention and Control Services office began working with the San Francisco Department of Public Health Lab to further examine screening practices. Two changes were made in testing procedures: an "other" box was omitted from the lab requisition form (since no other reason for testing would fall under the department's guidance for screening), and lab personnel began electronically capturing the reason for each test.
STD Prevention and Control Services personnel then met with different test sites to review the new lab procedures. Prior to the program kickoff, a grace period was held, Bernstein explains. If specimens came in without a stated reason for testing, the lab would contact clinicians to let them know that while in the future specimens could not be submitted without a reason for testing, the specimen would be processed. However, as of Jan. 1, 2009, any specimen submitted to the San Francisco laboratory without a reason for testing listed on the requisition form would not be tested.
Did it work?
To see if the changes were effective, STD Prevention and Control Services compared testing volume and positivity from eight screening program sites during 2008 and 2009.
To see if the changes were effective, STD Prevention and Control Services compared testing volume and positivity from eight screening program sites during 2008 and 2009. During 2008, 893 chlamydia tests were run on females over age 25; 52 new infections were identified (5.8% positivity). During the same period in 2009, 922 chlamydia tests were run on women over age 25, with 60 infections identified (6.5% positivity). Compared to 2008, in 2009, the number of chlamydia tests submitted to the public health laboratory in women over 25 declined 24.4% while increasing 3.2% in females age 25 and younger. Seven fewer chlamydia infections was identified in the older population in 2009 compared to 2008, public officials note. The result? Unnecessary chlamydia testing among older females was reduced by 24% without largely appearing to impact case finding.4
The intervention has drawn interest from other programs, says Bernstein.
"While the intervention may not be necessarily appropriate everywhere, the approach and evaluation we took is applicable," he notes.