Published Online: June 04, 2010
Mona Saraiya, MD, MPH; Linda F. McCaig, MPH; and Donatus U. Ekwueme, PhD
Objectives: To establish current estimates and project potential reductions in the volume and cost of annual Pap tests administered at visits to physician office and hospital outpatient departments in light of cervical cancer screening changes and HPV vaccination.
Study Design: Assessment of baseline national administrative data and future projection.
Methods: We used data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) to analyze physician office and hospital outpatient department visits made by female subjects 15 years and older from 2003 through 2005.
Results: Pap tests were ordered annually at 30.2 million physician office and hospital outpatient department visits in the United States from 2003 through 2005. Among visits by young women aged 15 to 26 years, Pap tests were ordered at 5.8 million visits each year, representing 19.3% of all Pap tests ordered. Among visits made by women of childbearing age that included Pap tests, 76.0% occurred in obstetrics and gynecology offices or clinics. Using a simple projection model, we estimated an overall annual decrease of 1.2 million Pap tests for young women aged 15 to 26 years and a corresponding cost reduction of $77.6 million after routine HPV vaccination and HPV DNA testing. Among female subjects 15 years and older, the estimated potential decrease in Pap tests was 6.3 million, with an estimated $403.8 million in cost reduction.
Conclusions: The NAMCS and NHAMCS provide baseline data to estimate the effects of HPV vaccination and HPV DNA testing on cervical cancer screening policy. These future technologies may result in changes to cervical cancer screening policies and, when fully accepted and implemented, may reduce economic costs associated with cervical cancer in the United States.
(Am J Manag Care. 2010;16(6):e137-e144)
Assessment of the pre-human papillomavirus (HPV) vaccination burden of ambulatory care visits and procedures related to cervical cancer screening is provided, with projection of how HPV vaccination and testing may affect this burden.
Human papillomavirus vaccination and testing may affect the volume of Pap tests and cervical cancer procedures in the future.
National administrative data are used to assess baseline volumes of Pap tests and cervical cancer procedures and to project the effects of HPV vaccination and testing on numbers and cost.
Human papillomavirus (HPV) testing, approved for routine cervical cancer screening in 2003, and the HPV vaccine, approved for routine vaccination of girls in 2006, are shifting the paradigm of cervical cancer screening and management. Recommendations for the use of HPV DNA testing for cervical cancer screening and management and HPV vaccination for cervical cancer prevention since 2003 and 2006, respectively, could dramatically affect the volume of Pap testing, a traditional and successful method of screening for cervical cancer. Management of cervical cancer–related procedures can be expensive: $2.3 billion to $6 billion are spent each year on direct medical costs from abnormal Pap test results and other low-grade lesions.1-3 Human papillomavirus vaccination and DNA testing are expected to decrease these costs by reducing the required numbers of annual Pap tests and cervical cancer–related procedures.
In 2003, several organizations endorsed pairing HPV testing with Pap tests (HPV cotesting) as part of routine cervical cancer screening for women 30 years and older. Recent surveys of primary care providers estimate that about one-fifth of providers who offer Pap tests use the HPV test as a cotest.4 If most providers follow the recommended guideline of increasing the screening interval from 1 to 3 years for women who have both normal Pap tests and negative HPV test results, HPV cotesting is expected to decrease the number of Pap tests administered by 30%, from 65 million to 45.5 million, by 2010.5 By 2026, the HPV vaccine (approved for use in female subjects aged 11-26 years) is projected to decrease Pap test volume further by 13% as a result of shifting the age of Pap test initiation from 18 to 25 years among the fully vaccinated cohort of girls.5,6 Modeling studies also have projected a decrease in abnormal Pap test results and cervical cancer precursor lesions as a result of HPV vaccination. Sanders and Taira7 estimated a 21% reduction in the incidence of low-grade abnormal Pap test results over the lifetime of a vaccinated cohort of girls aged 12 years. Similarly, Kohli et al8 estimated a reduction in abnormal results of cytologies, colposcopies, and biopsies and in treatment of cervical intraepithelial neoplasia lesions over the lifetime of a 12-year-old cohort because of the HPV 16/18 vaccine. The numbers of colposcopies and other more serious procedures are projected to decrease by 12% and 42%, respectively, among women (negative to 14 HPV types at baseline) receiving the HPV vaccine based on evidence after 4 years of follow-up.9
Most projections of the number of Pap tests conducted annually are based on women’s self-reports.5,10 Self-reported data are subject to bias and could lead to an overestimation of adherence to screening.11,12 To date, no known study has used data abstracted from medical records to project the numbers of Pap tests and other cervical cancer–related procedures (ie, abnormal results of cytology, colposcopy, or biopsy and treatment of high-grade lesions) that are performed annually in the United States. Furthermore, few data are available on the number of abnormal Pap test results or colposcopies performed annually.
The objectives of this study were to use data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2003 through 2005 to establish a baseline for the number of Pap tests ordered in physician offices and hospital outpatient departments (OPDs) and the number of follow-up procedures related to the management of abnormal Pap test results performed before the 2006 approval of the HPV vaccine. We use these estimates to project the degree to which HPV vaccination and HPV DNA testing could reduce the use of ambulatory cervical cancer–related tests and procedures and to estimate the potential reduction in screening and procedure costs from a reduction in cervical cancer–related tests and procedures because of HPV vaccination and HPV DNA testing.
The NAMCS and NHAMCS are annual probability sample surveys conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention (CDC). The NAMCS uses a 3-stage probability sampling procedure that includes (1) 112 geographic primary sampling units, (2) a probability sample of physicians within primary geographic sampling units selected from the master files maintained by the American Medical Association and the American Osteopathic Association, and (3) a sample of about 30 visits during a randomly assigned reporting period of 1 week throughout the year. Sample design, sampling variance, and estimation procedures of the NAMCS have been described elsewhere.13 The NHAMCS uses a 4-stage probability sampling procedure that includes (1) the same 112 geographic primary sampling units used in the NAMCS, (2) a probability sample of nonfederal short-stay and general hospitals within the sampled primary sampling units selected from a publicly available database of all US hospitals, (3) emergency service areas within 24-hour emergency departments and clinics within OPDs, and (4) a sample of about 100 visits to emergency departments and 150 to 200 visits to OPDs during a randomly assigned reporting period of 4 weeks throughout the year; a published study14 describes the plan and operation of the NHAMCS. Only the OPD component of the NHAMCS was used in our analysis. The US Census Bureau is responsible for inducting NHAMCS hospitals and NAMCS physicians and for collecting sample encounter data. Additional information about the methods of the NAMCS and NHAMCS can be found on the Internet (http://www.cdc.gov/nchs/ahcd.htm).
From 2003 through 2005, the survey response rates averaged 66% for NAMCS and 86% for NHAMCS OPDs. The annual numbers of participating NAMCS physicians and NHAMCS OPDs were 1300 and 220, respectively, and the annual numbers of patient record forms completed by physician offices and OPDs were 25,000 for the NAMCS and 32,000 for the NHAMCS. Estimates for visits by female subjects 15 years and older are based on 88,151 sample records that resulted in 5165 sample visits at which a Pap test was ordered during the 3-year study period.
The same patient record form was used for NAMCS physicians and NHAMCS OPDs and contained demographic data about patients and information about the visit, including diagnosis, diagnostic and screening services, and ambulatory surgical procedures. As many as 3 diagnoses were coded according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM).15 “Pap test” is a check box on the patient record form and is marked if the test is ordered or provided. “Procedures” that were ordered or provided were written in and coded using ICD-9-CM procedure codes. For this analysis, it was assumed that the Pap test or procedure was provided at this visit or at a later date. “Preventive care (eg, routine, prenatal, well-child, screening, insurance, and general examinations)” is a check box on the patient record form.
We examined data from selected physician and OPD clinic specialties for which Pap test ordering is most likely to occur. Physician and clinic specialty is determined during the induction interviews for the NAMCS and NHAMCS, respectively. Physician specialty is not collected for the NHAMCS. For the NAMCS, obstetrics/gynecology (OB/GYN) was defined as a physician with that specialty, and general medicine (GM) was defined as a physician with the specialty of family medicine, internal medicine, or GM. For the NHAMCS, OB/GYN clinics included OPD clinics with that specialty. For the NHAMCS, GM clinics were defined more broadly than were GM physicians and may have included clinics that did not provide primary care.
Abnormal Pap test result and cervical dysplasia were defined as ICD-9-CM diagnosis codes 795.0 (without 622.1) and 622.1 (without 795.0), respectively. The ICD-9-CM procedure codes were used to define cervical procedures. Colposcopy was coded as 70.21 (vaginoscopy). Other cervical procedures were coded as 67.1 (diagnostic procedures on cervix), 67.2 (conization of cervix), and 67.3 (other excision or destruction of lesion or tissue of cervix, excluding 67.31).
We presented our data by various age categories (15-26, 27-44, and >45 years). The first age category is a group that could be eligible for receipt of the HPV vaccine under the current guidelines.16 The second and third age categories would not be eligible for HPV vaccine.
The NAMCS and NHAMCS data were weighted to produce national estimates, and 3 years of data were combined to increase the reliability of the estimates. The NAMCS weight includes the following 4 components: selection probability, nonresponse adjustment, physician-population weighting ratio adjustment, and weight smoothing. The NHAMCS weight includes the following 3 components: selection probability, nonresponse adjustment, and ratio adjustment to fixed totals. SUDAAN software 9.0.1 (Research Triangle Institute, Research Triangle Park, NC) was used for all statistical analyses.
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