A Paradox: Overscreening of Older Women for Chlamydia While Too Few Younger Women Are Being Tested

Berman, Stuart M. MD, ScM; Satterwhite, Catherine L. MSPH, MPH

doi: 10.1097/OLQ.0b013e3182027e00

From the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA.

Correspondence: Stuart M. Berman, MD, ScM, 1600 Clifton Road, Mailstop E07, Atlanta, GA 30333. E-mail: smb1@cdc.gov.

Received for publication September 14, 2010, and accepted October 17, 2010.

Article Outline

In this issue, Bernstein et al. report on a structural intervention aimed at reducing chlamydia screening among women aged ≥26 years.1 This article, though brief, provides an opportunity to highlight several issues related to chlamydia screening and sexually transmitted disease (STD)/human immunodeficiency virus (HIV) prevention in general.

The importance of screening young women for chlamydia should be reemphasized. The United States Preventive Services Task Force (USPSTF) recommends annual chlamydia screening for all sexually active young women aged <25 years.2 This is an “A” recommendation, meaning there is good evidence that the benefits of screening outweigh the harms.3 Conversely, USPSTF recommends against routinely screening women aged ≥25 years, unless the individuals are at increased risk of infection (e.g., history of sexually transmitted infections, new or multiple sex partners, inconsistent condom use, exchanging sex for money or drugs).

In particular, 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 USPSTF.4 Unfortunately, the National Commission on Prevention Priorities also identified chlamydia screening as one of the most underutilized among the high-ranking preventive services. Data from the Healthcare Effectiveness Data and Information Set show that, although chlamydia screening coverage among sexually active young women seeking health care has increased steadily over time, coverage is still low.5 In 2008, 40.1% of sexually active women aged 16 to 20 years who were enrolled in commercial plans were screened for chlamydia; 52.7% of sexually active women aged 16 to 20 years in Medicaid managed care were screened.6 Among women aged <25 years who attended federally funded Title X family planning clinics, 55% were tested for chlamydia in 2008.7 The proportion of women aged ≥25 years who were tested was 42% in this population; it is highly unlikely that all of these women were tested due to a risk factor.

The recently passed Affordable Care Act may help increase chlamydia screening coverage; the law requires that group health and individual insurance plans cover recommended preventive services such as chlamydia screening (i.e., USPSTF A or B recommendations) without cost sharing.8

Although too few young women are being tested for chlamydia, paradoxically, it appears that too many older women are receiving such testing. In Bernstein et al., the authors have highlighted an issue that has not received much attention: many providers are inappropriately screening older women (≥26 years) for chlamydia. As Bernstein et al., report, and as others have discovered, it can be challenging to get providers to refrain from performing chlamydia tests among low-prevalence populations, particularly older women. While the guidance in San Francisco is consistent with national recommendations and focuses primarily on screening among younger females, 64% of tests submitted to the San Francisco Public Health Laboratory in 2008 were among women aged ≥26 years. Nationally, of the nearly 2.7 million chlamydia tests reported through the Infertility Prevention Project (IPP) in 2008, 36% (>948,000 tests) were among women aged ≥25 years (unpublished data). As expected, the disease burden differs substantially by age. Consistent with differences reported by Bernstein et al., the national median state-specific chlamydia positivity in 2009 among women aged 15 to 24 years who attended family planning clinics participating in IPP was 7.4%; among women aged ≥25 years, positivity was 3.5% (unpublished data, LaZetta Grier BS, September, 2010).9

Like the San Francisco Department of Public Health, other public health entities are also trying to reduce overscreening of women aged ≥25 years. Rabins et al. in the Illinois Department of Health also used a laboratory-based intervention that resulted in a 22% decrease in tests among older women.10 By implementing a test allotment system based on age and positivity, testing sites were encouraged to better target screening. Bornmueller et al. described creation of a policy whereby IPP funds would not be used to perform tests at the state laboratory (Iowa) on any women aged ≥35 years, resulting in a 14% decrease in the overall number of specimens submitted.11 Using another laboratory-based intervention, the Washington State Department of Health began to bill clinics for tests that were ordered among (lower-risk) women for whom screening was not recommended; this resulted in a test reduction of 10% (K. Gudgel and D. Fine, written personal communication, September 2010).

There is another issue raised by the authors' results, namely the performance of existing recommendations concerning screening for chlamydia among women aged ≥26 years. The rationale for recommending screening among young women (i.e., aged ≤25 years) is well supported by a substantial volume of evidence.2,3 The recommendations for screening among older women are considerably less specific and open to interpretation (USPSTF: “risk factors for chlamydial infection include a history of chlamydial or other sexually transmitted infections, new or multiple sexual partners, inconsistent condom use, and exchanging sex for money or drugs”); in general, few evaluations have been done on the performance of these criteria among older women in general populations.12

Since positivity was lower among older women and most of the tests were performed among this group, Bernstein et al. sought to reduce the number of tests that were performed among those women aged ≥26 years of age—particularly among those older women at lower risk for chlamydia. Testing among those women aged ≥26 years with risk factors was supported (i.e., symptoms, contact to partner with chlamydia, and 3-month screening after treatment for chlamydia). Such a policy is predicated upon the assumption that older women with any of those factors were at greater risk of infection than women lacking them. But the results were not consistent with that assumption: the positivity among women aged ≥26 years was essentially the same before and after the intervention (2.3% vs. 2.4%) even though testing volume among older women decreased by almost 25% (testing among younger women increased by over 3%). Therefore, the population of women aged ≥26 years that was tested in 2009 was not at higher risk than that tested in 2008. Unless the clinic population changed substantially over 1 year, such a finding suggests that the authors should revisit the criteria being used. In fact, given the ambiguity of existing recommendations for screening older women, this issue is broadly relevant, and criteria for screening older women for chlamydia should be reevaluated.

The authors indicate that provision of “technical assistance” did not change screening behavior of providers; in 2008, 64% of tests were still performed among women ≥26 years of age. Previous efforts, including site visits, trainings, and shared data, did not impact the proportion of tests submitted among older women. However, change was achieved, resulting in a 24% decrease in tests among older women, by changing the “rules”; tests were not paid for unless criteria were met. Using policy to address public health problems—a type of structural intervention—is of increasing attractiveness to public health officials. Such structural interventions tend to be more effective than behavioral interventions.

In fact, the director of the Centers for Disease Control and Prevention, Dr. Thomas Frieden, has been encouraging the use of such approaches, particularly with regard to fighting chronic conditions such as childhood obesity.13,14 Structural interventions clearly have relevance for STD/HIV prevention. For example, raising taxes on alcohol can reduce alcohol consumption—associated with rates of gonorrhea among young people, and requiring immunization (including for hepatitis B vaccine) for school enrollment increases vaccine coverage.15–17 Such approaches are relatively inexpensive and likely to be sustainable and effective. This contrasts with individual level interventions, which can require substantial resources, and, whether focused on providers, partners, or at-risk populations, are unlikely to reach all those for whom the intervention is intended.18 Although a wide variety of structural interventions have been implemented to address alcohol, smoking, and injury, such interventions have been less widely implemented for STD/HIV prevention in the United States.19 However, the recent changes regarding syringe exchange and removal of regulatory barriers to expedited partner treatment are examples of structural interventions that address STD/HIV prevention.20,21

While large-scale, national structural changes offer the best opportunity for maximal impact, local programmatic research and innovation are critical for identifying, establishing, and evaluating effective interventions that may be broadly relevant. Efforts like those undertaken by Bernstein et al. are an important component to the advancement of STD/HIV prevention.

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