Concept: Cervical Cancer Screening (Pap test)

Definition of Cervical Cancer Screening

Also called a Pap (Papanicolaou) test, cervical cancer screening is based on the examination of cells collected from the cervix to reveal pre-malignant (before cancer) and malignant (cancer) changes as well as changes due to non-cancerous conditions such as inflammation from infections.

How to identify Cervical Cancer Screening in Administrative Claims Data

Pap tests are predominately done in a physician's office, either during a complete physical examination or in a separate visit. On rare occasions, Pap tests are completed in hospital; however, these Pap tests are most likely not carried out for screening purposes, but to examine the patient subsequent to a screening Pap test that has come back positive for pre-cancerous cells or cancer, or to examine a patient who has never been screened and has cervical cancer symptoms. As the main purpose of cervical cancer screening is to identify potential problems in women before they develop cervical cancer, Pap tests in hospital are not usually included in the cervical cancer screening definition. A list of related ICD-9-CM / ICD-10 diagnosis and procedure / CCI codes found in hospital data are presented in the Notes and Cautions section below.

Pap tests are identified in the physician / medical claims data using the following physician tariff codes with tariff prefix = 7:


• 8470 - GP - Regional Gynaecological Exam - Including Cytological Smear - Cervix
  
• 8495 - OBS/GYN - Complete Physical and Gynaecological Exam - Including Cytological Smear - Cervix
  
• 8496 - OBS/GYN Visit - Regional Gynaecological Exam - Including Cytological Smear - Cervix
  
• 8498 - GP - Complete Physical and Gynaecological Exam - Including Cytological Smear - Cervix
  
• 9795 - Cytological Smear of the Cervix for Cancer Screening

Pap tests can also be identified in medical claims using the following pathology or laboratory tariff code with tariff prefix = 8:


• 9470 - Cytological Examination - Vaginal Smear

NOTE: In 2015, MCHP added the Cervix Screening data from CancerCare Manitoba to the Data Repository, beginning with data in 2001. This data can also be used to investigate the occurrence of cervical cancer screening / PAP tests in Manitoba.

Notes and Cautions

Tariff Codes

Another cervical cancer screening tariff code that is usually NOT INCLUDED due to age restrictions in the definition is:


• 8450 - Complete Physical and Gynaecological Exam - Including Cytological Smear - Cervix for Patients Aged 70 years and over

The list of tariff codes above is current as of March 31, 2006, and the addition / removal of new or existing tariff codes should be checked for any research or analysis past this date.

About Pap Test Claims

Most Pap tests will generate two claims, one from the physician who performed the test, and one from the lab where the cytological smear was analyzed. There are some instances where a physician claim tariff will not have a corresponding lab tariff or vice versa. One example of this is when a salaried physician does not shadow bill and so the only evidence of the Pap test will be the lab tariff. As such, it is important to include both physician claim tariffs and lab tariffs when identifying cervical cancer screening so as to not miss any Pap tests.

When calculating cervical cancer screening rates overtime, care must be taken to not inflate the actual rate by counting the same Pap tests in multiple time periods. As most Pap tests will have two medical claims associated with them, the physician claim and the lab claim, it is possible that the physician claim may appear in one time period, and the corresponding lab claim may appear in the next time period.

The majority of physician and lab claims for the same woman's Pap test are dated within a few days of each other. However, some lab claims may be dated up to a year after the date of the physician claim. The question then becomes: When to count a lab claim as a subsequent Pap test? Alain Demers at CancerCare Manitoba has done considerable work exploring this issue and has discovered that 98.7% of lab claims are within 54 days of the physician claim. An algorithm developed for calculating cervical cancer screening rates over time based on his work is:

If a lab tariff is within 54 days of a physician claim for a Pap test for the same woman, the two claims should be counted as one PAP test to reduce double counting over 3 year periods. Please see SAS code below on this algorithm.

Other Diagnoses and Procedure Codes

Other cervical cancer screening-related diagnoses and procedure codes found in hospital claims that are NOT RECOMMENDED FOR A CERVICAL CANCER SCREENING DEFINITION , include:


• ICD-9-CM diagnosis codes: 795.0, V67.01, V76.2, V76.47
• ICD-9-CM procedure code: 91.46
• ICD-10-CA diagnosis codes: R87.6, Z01.4, Z12.4
• CCI codes: 2.RN.71.CA, 4.AH.02.77

Women who had a complete hysterectomy are excluded from both the numerator and denominator. Hysterectomy surgeries are defined by hospital separations with ICD-9-CM procedure codes 68.4-68.9 and CCI codes 1.RM.89, 1.RM.91, 5.CA.89.CK, 5.CA.89.DA, 5.CA.89.GB, 5.CA.89.WJ and 5.CA.89.WK. These codes cover only total hysterectomies, not partial, as women who have a partial hysterectomy may still have a cervix and would require cervical cancer screening.

In Katz et al. (2019), women with a previous diagnosis with cervical cancer were excluded.

Pap Tests Performed By Nurses

In some areas, Pap tests are also performed by nurses, but these services may not appear in the administrative data. For example, rates for northern and remote areas served by nursing stations may be underestimated due to missing data. Prior to 2005, only physicians were able to code into the administrative billing system for Pap tests. As of 2005, nurses officially called "Nurse Practitioners" by Manitoba Health are able to make claims into the physician data system. However, "Advanced Practice Nurses" or other designations are not included in the Nurse Practitioner designation, despite the fact that some do Pap tests. Nurses working at federally-operated Nursing Stations also do not record their work in the billing claims system. However, most nurses who are not nurse practitioners would be doing Pap tests under the supervision of a physician, who would most likely be billing for these.

Cervical Cancer Screening Rates

Rates of cervical cancer screening are calculated as the proportion of women age 18-69 that have had at least one Pap test in a three year period. The first (or last) Pap test in the three years is counted as women may have more than one test during the three years. For provincial rates, the denominator is the number of women age 18-69 as of December 31 in the mid year of the three year period.

Who Should Get Checked?

The following information is available on the CancerCare Manitoba Web Site - CervixCheck - accessed July 11, 2016.

Most women ages 21-69, who have ever been sexually active should have a regular Pap test every 3 years. Sexual activity includes sexual intercourse as well as genital skin-to-skin touching, with a male or female partner.

Why Every 3 Years?

Having a Pap test every year or two offers very little added benefit over having a Pap test every three years and can expose women to unnecessary harms including:


• Discomfort or bleeding from the test,
  
• Anxiety that may results from abnormal test results,
  
• Over-diagnosis of abnormal cell changes that would go away on their own, and
  
• Problems with future pregnancies from some treatments during colposcopy.

Why are Pap tests not recommended for women under 21 years of age?

Cervical cancer is very rare in women younger than 21 years of age. As well, the harms of screening women under 21 significantly outweigh the benefits.

You should still have regular Pap tests if you:


• are past menopause
  
• have ever been sexually active and are currently not sexually active
  
• are in a same-sex relationship
  
• are trans
  
• have had 1 sexual partner
  
• are in a long-term relationship
  
• have had the HPV vaccine

Data Cautions / Limitations

Pap test data can be found in several data sources (e.g. Medical Services / Medical Claims, laboratory tests, CancerCare Manitoba screening program data). If using more than one data source, please check for duplication to avoid over counting.