Cervical Cancer Screening

Measure Description

Name	Description	Numerator	Denominator	Source	Reference
Cervical Cancer Screening	Percentage of women 21 to 64 years of age who received one or more Pap tests	Women in the denominator with one or more Pap tests during the measurement year or two years prior to the measurement year	All women patients 24 to 64 years of age during the measurement year or 2 years prior to the measurement year	NCQA/NQF 2008	National Committee for Quality Assurance

Part 1: Introduction

Part 2: Characteristics for Success: Cervical Cancer Screening

Part 3: Implementation of Clinical Quality Measure: Cervical Cancer Screening

Part 4: Improvement Strategies: Cervical Cancer Screening

Part 5: Holding the Gains and Spreading Improvement

Part 6: Supporting Information

Part 1: Introduction 

Cervical cancer is a slow-growing cancer that develops in the tissues of the uterine cervix. It does not typically have any symptoms and is almost always caused by human papillomavirus (HPV) infection. Effective screening and treatments continue to decrease the incidence of cases and deaths from cervical cancer. Women in developing countries account for the majority of cases and deaths related to this type of cancer. It was estimated that in 2009, there would be 11,270 new cases and 4,070 deaths from cervical cancer.⁽¹⁾ The lifetime probability of developing cervical cancer is 0.75 percent and 0.27 percent lifetime probability of death. ⁽²⁾

Despite the low incidence numbers for cervical cancer, there are differences among racial and ethnic groups. Table 1.1 summarizes the data displayed in Figures 1.1 and 1.2, which shows incidence rates are highest for Hispanics, followed by Blacks, Whites, Asian/Pacific Islanders, and American Indian/Alaska Natives. Death rates are highest for Blacks, followed by Whites, Hispanics, American Indian/Alaska Natives, and Asian/Pacific Islanders [see table and figures].⁽³⁾

Table 1.1: Cervical Cancer Incidence and Death Rates per 100,000 Persons in the United States 

Incidence source: Surveillance, Epidemiology, and End Results (SEER) Program, National Cancer Institute (NCI) 1975–1991 = SEER 9; 1992–2005 = SEER 13.
*Rates are per 100,000 and are age-adjusted to the 2000 U.S. standard population (19 age groups - Census P25-1130).
Rates for American Indians/Alaska Natives are not displayed because fewer than 16 cases were reported for at least one year within the time interval.
‡Hispanics are not mutually exclusive from Whites, Blacks, Asians/Pacific Islanders, and American Indians/Alaska Natives. Incidence data for Hispanics are based on North American Association of Central Cancer Registries (NAACCR) Hispanic Identification Algorithm (NHIA) and exclude cases from the Alaska Native Registry.

Mortality source: U.S. Mortality Files, National Center for Health Statistics, CDC.
*Rates are per 100,000 and are age-adjusted to the 2000 U.S. standard population (19 age groups - Census P25-1130).
Rates for American Indians/Alaska Natives are not displayed because fewer than 16 cases were reported for at least one year within the time interval.
‡Hispanics are not mutually exclusive from whites, blacks, Asians/Pacific Islanders, and American Indians/Alaska Natives. Mortality data for Hispanics do not include cases from Connecticut, Maine, Maryland, Minnesota, New Hampshire, New York, North Dakota, Oklahoma, and Vermont.⁽⁴⁾

The racial and ethnic differences are thought to reflect disparities in access to screening and treatment. The high death rate for Blacks implies they lack access to treatment. The higher incidence rate among Hispanics infers that a significant proportion is immigrants from countries where screening and treatment are less accessible. Rates of cervical cancer in Mexico and Latin America are three times higher than in the United States due to less screening. ⁽⁵⁾

The link between cervical cancer and HPV infection highlights risk factors, screening priorities, and prevention strategies. There are over 100 types of HPV and several are considered high risk for causing cervical cance-especially types 16 and 18. A study from the National Health and Nutrition Examination Survey (NHANES) showed 26.8 percent of women aged 14 to 59 years tested positive for at least one strain of HPV with higher incidence ⁽⁶⁾ in young women. The sexually-transmitted virus does not typically present symptoms and persists for many years. An infection can resolve spontaneously, but a persistent infection can cause abnormal changes in cervical cells, which develop into cancer over the course of several years.

Gardasil® was approved in 2006 and provided another prevention strategy for cervical cancer. Females aged 9 to 26 years are vaccinated against HPV types 6, 11, 16, and 18 with three separate injections. In 2009, Cervarix® was introduced, which targets HPV types 16, 18, 31, 33, and 45, and was approved for boys. While vaccination may have an impact on cervical cancer incidence, it will not replace screening anytime soon.

Cervical and colorectal cancers are the only two that can be prevented through screening. ⁽⁵⁾ There are clinical issues with determining who should be screened and how, such as, risk stratification, and what age to begin and stop screening. Screening guidelines have changed as clinicians gained a better understanding of HPV. As of November 2009, the American College of Obstetricians and Gynecologists (ACOG) recommends cervical cancer screening begin at age 21 years regardless of sexual history. Screening before age 21 should be avoided because young women are at very low risk of cervical cancer, and it may lead to unnecessary and harmful evaluation and treatment. Cervical cytology screening is recommended every 2 years for women aged 21 to 29 years. Evidence shows that annually screening women of average risk has little benefit over screening biennially. ⁽⁷⁾ Screening is not required for women who have undergone hysterectomy including removal of the cervix.

Today, Papanicolaou (Pap) testing is the primary screening for cervical cancer. It is valuable for detecting pre-cancerous cells and lesions, which are simpler to treat than invasive cancer. The conventional Pap slide “smear” and the newer liquid-based cytology use similar technologies in examining cervical cells for abnormality. Evidence is mixed on which is more accurate. ^(14,15,16)

The HPV test is being studied for screening cervical cancer and pre-cancerous conditions. It is currently used with Pap cytology to assist clinical decision-making, and guidelines for its use will evolve over time.

The United States made significant progress with meeting cervical cancer challenges and ensuring screening procedures are an accepted routine for American women and health care professionals. Since cervical cancer is largely a preventable disease, improved screening rates should continue to be a priority.

Note: With the recent recommendations from the American College of Obstetricians and Gynecologists (ACOG), national authorities are looking at aligning measures with the new guidelines. Decisions on a clinical level and informing patients on the benefits and risks of screening remain essential in determining who should be screened for cervical cancer.

Measuring performance allows an organization to document how effectively care is provided and lays the foundation for improvement. 

The Cervical Cancer Screening clinical quality measure is designed to measure the percentage of patients aged 21 to 64 years who have been screened with one or more Pap tests. This measure is intended to focus on appropriate screening for those women of average risk for cervical cancer. The goal is to further reduce the morbidity and mortality associated with cervical cancer by ensuring that patients access Pap tests, a highly effective screening test for cervical cancer, at least once in three years.

Measuring performance on this clinical quality measure encourages an organization to improve systems so that all women of appropriate age have access to regular and ongoing screening for cervical cancer. This performance measure focuses on systems for Cervical Cancer Screening for women of average risk, but work to improve performance on this measure will likely improve Cervical Cancer Screening for all women including those at high risk.

Consider the characteristics of a good performance measure and the Institute of Medicine (IOM) framework Envisioning the National Healthcare Quality Report :

• Relevance: Does the performance measure relate to a frequently-occurring condition or have a great impact on patients at an organization's facility?
• Measurability: Can the performance measure realistically and efficiently be quantified given the facility's finite resources?
• Accuracy: Is the performance measure based on accepted guidelines or developed through formal group decision-making methods?
• Feasibility: Can the performance rate associated with the performance measure realistically be improved given the limitations of the clinical services and patient population?

To ensure that a performance measure has these characteristics, it is often based on, or aligned with, current evidence-based guidelines and proven measures.

The Cervical Cancer Screening measure aligns with measures endorsed by the National Committee for Quality Assurance (NCQA) and similar performance metrics used by HRSA grantees and programs. Similar measures also exist in the national measure set for Healthy People 2020.

Clinical Quality Measure: Cervical Cancer Screening

Measure Description 

Name	Description	Numerator	Denominator	Source	Reference
Cervical Cancer Screening	Percentage of women 21 to 64 years of age who received one or more Pap tests	Women in the denominator with one or more Pap tests during the measurement year or two years prior to the measurement year	All women patients 24 to 64 years of age during the measurement year or 2 years prior to the measurement year	NCQA/NQF 2008	National Committee for Quality Assurance

As with all performance measures, there are essential inclusions, exclusions, and clarifications that are required to ensure that an organization collects and reports data in the same way. This allows an organization using the measure to compare itself with others. Detailed specifications for the measure, with descriptions of inclusion and exclusion criteria, are found in the section, Part 3: Data Infrastructure: Cervical Cancer Screening.

Practical Considerations

Health care professionals should be familiar with several key topics to appropriately screen women for cervical cancer. Advanced discussion is beyond the scope of this module, but the reader is encouraged to review other resources for further information including those listed in Part 6: Additional Resources.

Risk Factors Associated with Cervical Cancer

Patients may ask health care professionals about risks associated with cervical cancer and what can be done to prevent it. Evidence reveals the following are risk factors for cervical cancer:

• HPV infection
• Lack of regular Pap tests
• Weakened immune system
• Age over 40
• Sexual history—many partners or partner with many partners
• Smoking cigarettes
• Using birth control pills for five or more years
• Having many children
• Diethylstilbestrol (DES) exposure

1. Avoidance of HPV infection
   • Abstinence from sexual activity
   • Barrier protection and/or spermicidal gel during sexual intercourse
   • Vaccination against HPV infection
2. Cervical cancer screening
   • Regular gynecological examination and Pap testing
3. Avoidance of cigarette smoking (active or passive)
4. Reproductive behaviors
   • High parity
   • Long-term use of oral contraceptives

Understanding Benefits and Harms of Screening

Data indicates that women who have been screened are less likely to develop or die from cervical cancer, because screening reveals abnormalities in early treatable stages--a benefit that increases with age. Evidence shows that cervical cancer mortality usually occurs among unscreened women. The maximum mortality for White women is between the ages of 45 and 70 years and for Black women is in their 70's.^(18,19) Mortality among women with negative Pap screening is low for all ages.

Screening recommendations carefully balance the benefits and harms associated with various screening techniques. Approximately six percent of women who receive Pap tests are referred for additional testing or treatment based on abnormal results. The potential harm of those referrals deserves consideration. Procedures may result in significant expense, discomfort, and permanent alteration of cervical tissue. Since some abnormalities resolve spontaneously or do not progress to cervical cancer, these consequences can be categorized as harms. Other harms of screening may include the impact of false positive screenings or inappropriate education about the significance of abnormal test results.

The Importance of Shared Decision Making 

The consensus on current cervical cancer screening guidelines is high but an organization should consider individual patient risks and benefits when making its screening recommendations. For example, shorter screening intervals for a woman infected with HIV or whose immunity is otherwise compromised may be warranted.

It is important for an organization to discuss factors with the patient that have an impact on her decision about screening, such as, individual risks, fears of diagnosis and harm from screenings, cultural influences, previous experiences, values, and perceived barriers to screening. Salient highlights of the discussion and decision should be documented in the medical record for all female patients.

Improvement Experience: Cervical Cancer Screening

The Cervical Cancer Screening measure was chosen to align with existing measures. The data demonstrating the experience with these measures is discussed briefly in this section.

The importance of Cervical Cancer Screening as part of comprehensive preventive care for women is widely accepted. Increased screening rates, since the Pap test was introduced in the 1940's, caused dramatic declines in cervical cancer incidence and mortality rates. A systematic approach achieves continued improvements in the quality of care delivery and reliable screening for patients.

Healthy People 2010 Objective 3-11b reports the percentage of women aged 18 years and older, who self-reported receiving a Pap within the past three years, decreased from 79 percent in 1998 to 76 percent in 2008 (with a 2010 target of 90 percent). In 2008, HRSA's Bureau of Primary Health Care introduced the Cervical Cancer Screening measure as part of a set of required core measures. Nationally-aggregated data from health centers revealed that 56.9 percent of women in the targeted age group received at least one Pap test documented in their medical records. ⁽²⁰⁾

em>Note that self-reported Pap screening may result in an optimistically high rate compared to medical record documentation.

In 2009, Healthcare Effectiveness Data and Information Set (HEDIS) data showed stagnant rates of cervical cancer screening in recent years shown in Table 1.2. [PDF | 1.7MB] There are significant differences between rates for women with commercial insurance compared to Medicaid-insured women.

Table 1.2: Cervical Cancer Screening Trends 2003-2008 

In 2003, 79 percent of women aged 18 years and over reported a Pap smear within the past 3 years. Among women 25 to 44 years of age, Pap smear use was lowest for women with less than a high school education (72 percent) and highest for women with at least some college education (91 percent). ⁽²¹⁾

When an organization implements systems to track values, its effectiveness for screening a patient population for cervical cancer is understood. Women of the target age range comprise a significant percentage of the total number of patients in a practice. Systems must be robust to track interval care for large numbers of individuals. Tracking systems also facilitate management and follow-up for patients with positive screening tests and provide critical steps to promptly connect them with appropriate care.