Association of Insurance Coverage With Chlamydia Screening

April 15, 2008
Nadereh Pourat, PhD
Nadereh Pourat, PhD

Guoyu A. Tao, PhD
Guoyu A. Tao, PhD

Cathleen M.Walsh, DrPh
Cathleen M.Walsh, DrPh

Volume 14, Issue 4

Among young, sexually active women, self-reported Chlamydia trachomatis screening rates were primarily influenced by risk factors rather than insurance coverage.

Objectives: To examine the rates of self-reported Chlamydia trachomatis (CT) screening among young women and to examine the independent association of type of insurance and specific health plans with these rates.

Study design

: Cross-sectional analyses of the 2003 California Health Interview Survey data.


: Using bivariate analysis and logistic regression models, we assessed the CT screening rate of 1659 sexually active women age 18-25 years, given various factors including type of health insurance coverage. We further assessed the CT screening rate of the subset of 533 sexually active women age 18-25 years enrolled in a private health plan and reexamined the relationship of various factors with CT screening rates.

Results: Being older, an immigrant, or having 1 sexual partner reduced the likelihood of CT screening, while being a smoker, being single, or having had multiple doctor visits as well as a Pap test or clinical breast exam increased this likelihood. The uninsured had the lowest rate, and public managed care enrollees had the highest rate, of CT screening, but this insurance effect was superseded by other explanatory variables. A few differences in significantly associated factors were identified when private health plans were separately examined.

Conclusions: The results suggest that self-reported CT screening rates were low, particularly among the uninsured. However, these rates were primarily influenced by CT risk factors rather than insurance coverage. Continued efforts to increase CT screening rates are warranted.

(Am J Manag Care. 2008;14(4):197-204)

Examination of self-reported Chlamydia trachomatis (CT) screening rates among insured and uninsured California women age 18-25 years indicated that:

The screening rates were primarily influenced by CT risk factors rather than insurance coverage.

The overall rate of CT screening was low.

Continued efforts to increase CT screening are warranted.

Chlamydia trachomatis (CT) infection is the most commonly reported sexually transmitted disease (STD) in the United States.1 Over the last decade, the Centers for Disease Control and Prevention, the US Preventive Services Task Force, and several professional organizations (eg, the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, the American Medical Association) have recommended routine screening for CT infection for all sexually active women age 25 years and younger and for pregnant women of all ages, with a few variations in these recommendations.2-7 In addition, the National Committee for Quality Assurance (NCQA), a private, not-for-profit organization that monitors the quality of the majority of managed care organizations (MCOs) through voluntary reporting of performance measures, instituted CT screening as a performance measure into the Healthcare Effectiveness Data and Information Set (HEDIS); this measure calls for monitoring of annual CT screening of sexually active women age 16-25 years.8

Since 2000, NCQA has measured CT screening rates for sexually active female enrollees of MCOs by using medical claims and pharmacy data. Of the commercial plan female enrollees age 16-25 years, 22% to 34% were screened for CT infection in 2000-2005.9 Of Medicaid plan female enrollees age 16-25 years, 37% to 50% were screened in 2000- 2005. Screening rates, as identified by HEDIS data, have increased marginally on a national basis since the initiation of the HEDIS measure. HEDIS data are not reported for all insured populations, given the voluntary nature of the reporting, and little is known about CT screening rates for sexually active women without health insurance.

Additionally, there is insufficient literature on the factors associated with the probability of CT screening for all sexually active young women, including insurance coverage. Despite the scarcity of information, a variety of efforts to increase CT screening have been undertaken to varying degrees of success. These efforts include educating sexually active young women to seek screening, encouraging health plans to promote CT screening, working with practitioners to increase awareness of guidelines recommending screening, and providing system support to clinical practices to routinely screen eligible women.

Information is emerging on MCOs’ promotion of CT screening, although data that link MCO initiatives and CT screening rates of their enrollee population are limited. To date, few studies have assessed the reasons for low rates of CT screening at the population level, including demographics, risk factors, insurance coverage, and access to care. This study aims to address these gaps by answering the following 2 questions: (1) What is the self-reported CT screening rate of the entire population of sexually active women age 18-25 years, including the uninsured? (2) What individual factors are associated with these CT screening rates, both for the entire population and for individuals who belong to private MCOs?

METHODSData and SampleWe used the 2003 California Health Interview Survey (CHIS) for this study. CHIS is the largest state-level health survey, with more than 42,000 respondents, and is conducted in English, Spanish, and 4 Asian languages to capture the diverse populations of the state. Data collection methods are described elsewhere.10 CHIS is the first large-scale survey to include a specific question on CT screening for women age 18 years or older and includes health plan membership information that allows linkage with external MCO data. All sexually active women age 18-25 years (n = 1659) were included in the study sample. Women were classified as sexually active if they reported at least 1 sex partner in response to the following question in the 2003 CHIS: “In the past 12 months, how many sexual partners have you had?” Adolescents younger than age 18 years were not asked about their CT screening in CHIS and were thus excluded from the data analyses.

Dependent Variable

Demographics, risk factors and socioeconomic characteristics, health status, and access to care were assessed for this group of young women. Age was dichotomized into 2 groups: 18-20 years and 21-25 years. Respondents were classified as white, Latino, African American, Asian American, American Indian, or other. The education variable was dichotomized as 12 or fewer years versus more than 12 years. Immigrants were compared with the native born, and those with limited English proficiency were distinguished from those fluent in spoken English. Urban or rural area of residence was identified. Risk factors included a dichotomized variable about the number of sex partners (1 sexual partner in the past year vs 2 or more) and history of smoking tobacco (yes vs no). Socioeconomic factors included family type (married, single without children, and single with children), income less than 200% of the federal poverty level, and insurance status (uninsured, private MCO, private non-MCO, public MCO, and public non-MCO). Health status was self-assessed as fair/poor health versus excellent or good health. Indicators of access included usual source of care (none, private doctor, public provider/clinic), experiences of delay in obtaining needed care, a Pap test or a clinical breast exam in the past 12 months, or number of doctor visits (none, 1-4, and 5 or more) in the past 12 months. Visits to nurse practitioners or physician assistants who may perform CT screening were not included in the original variable in CHIS, allowing the inclusion of number of doctor visits in the models.

Analysis Methods

Table 1

The characteristics of the sample are reported in . Some characteristics of interest included a high rate of CT screening among individuals with a single sexual partner (83%), a relatively high rate of uninsurance (23%), and high rates of Pap tests (74%) and clinical breast exams (67%). The overall rate of self-reported CT screening was 25%, with differences in screening rates depending on demographics, risk factors and socioeconomic characteristics, and health status and access to care (Table 1). Specifically, significant variations by type of insurance existed. Those who were covered by non-MCO public insurance and those who were uninsured had the lowest rates of CT screening (18% and 20%, respectively) compared with individuals who had the other types of coverage.

We examined the independent association of individual characteristics with CT screening rates in a multivariate regression model. As shown in Table 2, immigrant respondents were less likely than native-born respondents to be screened (odds ratio [OR] = 0.4), and those with a single sexual partner were less likely than those with 2 or more partners to be screened (OR = 0.5). Alternatively, those who had ever smoked (OR = 2.0), were single without children (OR = 1.8), and were single with children (OR = 1.9) were more likely to be screened than those who never smoked or were married. Furthermore, those with 5 or more doctor visits (OR = 3.0) were more likely than those without any visits to be screened, and those with a Pap test (OR = 5.6) or a clinical breast exam (OR = 1.9) were more likely than those who did not receive either of these services to be screened. Controlling for other variables of interest, type of insurance was not independently associated with CT screening.


2. American College of Obstetricians and Gynecologists, Committee on Adolescent Health Care. Health Care for Adolescents. Washington, DC: American College of Obstetricians and Gynecologists; 2003.

4. US Preventive Services Task Force. Screening for chlamydia infection: recommendations and rationale. Am J Prev Med. 2001;20(2):90-94.

6. American Academy of Pediatrics, Committee on Practice and Ambulatory Medicine. Recommendations for preventive pediatric health care (RE9939). Pediatrics, 2000;105 (pullout).

8. National Committee for Quality Assurance (NCQA). HEDIS 2000: Technical Specifications.Washington, DC: NCQA; 2000.

10. California Health Interview Survey. CHIS survey methodology. Accessed May 23, 2007.

12. California Office of Patient Advocate. 2003 Quality of care report card. Accessed February 15, 2007.

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