Objectives: Despite recommendations for triennial cervical cancer screening for low-risk women aged 30 years and older, annual screening remains common. We studied how often women receiving care from an academically affiliated medical group were screened, and patient and provider factors associated with overuse and underuse. We also explored the impact of changing measurement intervals on computed screening frequency.
Design: The study included women aged 30 years and older continuously enrolled over a 3-year period and excluded women with history of abnormal screening and conditions of high risk for cervical cancer.
Methods: Administrative and laboratory data were merged to link Papanicolaou (pap) test results with patient and ordering provider characteristics. We used logistic regression to analyze multivariate models for overuse and underuse, and modified measurement intervals to test sensitivity to early and late pap smears.
Results:The 8018 women had a mean age of 48 years and 95% had an ambulatory physician visit during the observation period. Thirty-four percent of women received guideline-based screening, 45% had overuse, and 21% had underuse. Factors independently associated with overuse included younger age, more medical visits, contraceptive management visits, and gynecology provider specialty. Underuse was associated with older age, fewer medical visits, and increased comorbidity. Overuse was 47% if unsatisfactory paps were not considered and was reduced to 35% if the observation interval was reduced from 36 to 30 months.
Conclusion: Overuse and underuse of cervical cancer screening are common, and clinician and patient factors are identifiable to target quality improvement interventions. Modifying the measurement interval may improve the measure.
Michael A. Rodriguez, MD, MPH
For a decade, US medical professional organizations1,2
and the US Preventive Services Task Force (USPSTF)3
have suggested that low-risk women (history of multiple normal Papanicolaou [pap] tests, age over 30 years) receive cervical cancer screening every 3 years as part of routine preventive services. Prior to these guidelines, observational and case control studies supported similar clinical outcomes between 1- and 3-year intervals.4-11
However, surveys showed that most (60-70%) gynecologists and primary care providers continued to perform annual screening, and many were unaware of the new guidelines.12,13
Recently, the USPSTF solidified its recommendations for the 3-year interval,14-17
and they and the American College of Obstetricians and Gynecologists suggest a 5-year interval with negative HPV testing.18,19
A 2010 study using the National Ambulatory Medical Care Survey projected that triennial screening would reduce testing by 6.3 million pap tests per year and reduce costs by $403.8 million.17
An earlier study projected that an additional 69,665 pap smears and 3861 colposcopies would need to be performed in women 30 to 44 years of age to avert one case of cervical cancer by screening every year instead of every 3 years. For women 45 to 59 years old, 209,324 pap tests and 11,502 colposcopies would need to be performed.4 Using National Health Interview Survey data, projected compliance with triennial screening would decrease the anannual number of pap smears from 75 million to 34 million.20
Since 2009, a pay for performance measure has been applied to managed care plans in California to encourage triennial rather than more frequent screening, but there has been little exploration of cervical cancer screening rates in populations affected by this measure. Furthermore, preventing overuse might encourage underuse, so both should be simultaneously evaluated. To encourage targeted use of screening, understanding physician and patient factors associated with overuse and underuse is needed.
We evaluated usage of cervical cancer screening in one medical group’s patients with the goal of identifying factors amenable to intervention. In addition, we varied the time period of the 3-year measure and accounted for clinically insufficient pap tests to evaluate the proportion of patients that were close to receiving appropriate screening to test the clinical applicability of the measure, which is important in order to promulgate interventions with clinicians.