Epic Research is not viewable using Internet Explorer. Please try accessing it with an alternate browser.
Cosmos Study

Cervical Dysplasia Rates Remain Steady Despite Reports of Declines in Cervical Cancer Diagnoses

October 31, 2023
Dual-Team Study
Team A:Kersten Bartelt, RNAlex Piff
Team B:Brad Fox, MDNeil Sandberg

Key Findings

  • Cervical dysplasia is diagnosed at an average rate of 79 patients per 1,000 pap smears performed each month. This rate has generally not changed since 2018 apart from a temporary marked increase at the start of the COVID-19 pandemic, during which time screening volumes were atypically low. 

The U.S. Preventative Services Task Force (USPSTF) recommends that women aged 21 to 65 be screened every three to five years for cervical cancer.1 The Centers for Disease Control and Prevention (CDC) reported that the incidence of cervical cancer diagnoses has declined over the past couple of decades, likely in part due to the introduction of the human papilloma virus (HPV) vaccine.2 Cervical dysplasia is the presence of abnormal cells on the cervix, which can become cancerous. However, with early diagnosis and treatment, most cases do not progress to cancer.3 Cervical dysplasia is classified into CIN 1, CIN 2, and CIN 3 based on the thickness of epithelium affected by the abnormal cells, with CIN 3 being the most severe.3 

To determine whether cervical dysplasia diagnosis rates have changed over time in a similar pattern to cervical cancer, we evaluated 3,343,330 pap smears and 264,395 cervical dysplasia diagnoses between January 2018 and June 2023. We found that overall, the rate of cervical dysplasia diagnoses has remained consistent over time, with an average of 79 diagnoses for every 1,000 pap smears each month, as seen in Figure 1. This number nearly doubled in April 2020 to 159 diagnoses per 1,000 pap smears, likely reflecting that only patients with the highest risk of cervical cancer were tested at a time of generally reduced screening volume.4 The highest incidence of CIN classification in newly diagnosed patients is CIN 1, with an average of 47 diagnoses per 1,000 screenings. The incidences of CIN 2 and CIN 3 were lower, with an average of 6 and 11 diagnoses per 1,000 screenings, respectively. 

Figure 1
New Cervical Dysplasia Diagnosis Rates
New Cervical Dysplasia Diagnosis Rates
Figure 1. Monthly rates of new cervical dysplasia diagnoses per 1,000 pap smear procedures.

Stratifications by patient age, race and ethnicity, and social vulnerability index followed the same pattern as the overall rate, remaining steady throughout the study period apart from April 2020. 

These data come from Cosmos, a HIPAA-defined Limited Data Set of more than 220 million patients from 221 Epic organizations including 1,260 hospitals and more than 27,100 clinics, serving patients in all 50 states and Lebanon. This study was completed by two teams that worked independently, each composed of a clinician and research scientists. The two teams came to similar conclusions. Graphics by Brian Olson.

  1. Cervical cancer: Screening. (2018, August 21). Uspreventiveservicestaskforce.org; US Preventive Services Taskforce. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/cervical-cancer-screening 
  2. Cervical cancer rates have dropped among young women in the United States. (2023, May 24). Cdc.gov. https://www.cdc.gov/cancer/dcpc/research/articles/cervical-cancer-rates-young-women.htm 
  3. Cervical dysplasia. (2022, January 31). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/15678-cervical-intraepithelial-neoplasia-cin 
  4. Alban, C., Sahakian, S., Allen, S., & Stamp, T. (2023, February 17). Missed Cancer Screenings Not Yet Associated with Increased Cancer Rates or Severity. Epic Research. https://www.epicresearch.org/articles/missed-cancer-screenings-not-associated-with-increased-cancer-rates-or-severity