Accuracy of the Papanicolaou Test in Screening for and Follow-up of Cervical Cytologic Abnormalities

Accuracy of the Papanicolaou Test in Screening for and Follow-up of Cervical Cytologic Abnormalities

A Systematic Review

From Duke University Medical Center and Durham Veterans Affairs Medical Center, Durham, North Carolina.

Abstract

Purpose: To evaluate the accuracy of conventional and new methods of Papanicolaou (Pap) testing when used to detect cervical cancer and its precursors.

Data Sources: Systematic search of English-language literature through October 1999 using MEDLINE, EMBASE, other computerized databases, and hand searching.

Study Selection: All studies that compared Pap testing (conventional methods, computer screening or rescreening, or monolayer cytology) with a concurrent reference standard (histologic examination, colposcopy, or cytology).

Data Extraction: Two reviewers independently reviewed selection criteria and completed 2 × 2 tables for each study.

Data Synthesis: 94 studies of the conventional Pap test and three studies of monolayer cytology met inclusion criteria. No studies of computerized screening were included. Data were organized by cytologic and histologic thresholds used to define disease. For conventional Pap tests, estimates of sensitivity and specificity varied greatly in individual studies. Methodologic quality and frequency of histologic abnormalities also varied greatly between studies. In the 12 studies with the least biased estimates, sensitivity ranged from 30% to 87% and specificity ranged from 86% to 100%.

Conclusions: Insufficient high-quality data exist to estimate test operating characteristics of new cytologic methods for cervical screening. Future studies of these technologies should apply adequate reference standards. Most studies of the conventional Pap test are severely biased: The best estimates suggest that it is only moderately accurate and does not achieve concurrently high sensitivity and specificity. Cost-effectiveness models of cervical cancer screening should use more conservative estimates of Pap test sensitivity.

Article and Author Information

Disclaimer: This article is based on an evidence report prepared by Duke University under contract with the Agency for Healthcare Research and Quality (AHRQ contract 290-97-0014). The authors are responsible for its content, including any clinical or treatment recommendations. No statement in this article should be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
Acknowledgments: The authors thank Jean Slutsky of the Agency for Healthcare Research and Quality for overall project guidance, Jane Kolimaga for organization and management of the project, Ruth Goslin and Rebecca Gray for assistance with manuscript preparation, and the Advisory Panel and peer reviewers of the Evidence Report for many helpful suggestions throughout the entire process.
Grant Support: Dr. Nanda was a Veterans Affairs Women's Health Fellow at the Durham Veterans Affairs Medical Center while conducting this study.
Requests for Single Reprints: Kavita Nanda, MD, MHS, Clinical Research Department, Family Health International, Box 13950, Research Triangle Park, NC 27709; e-mail, knanda{at}fhi.org.
Requests To Purchase Bulk Reprints (minimum, 100 copies): the Reprints Coordinator; phone, 215-351-2657; e-mail, reprints{at}mail.acponline.org.
Current Author Addresses: Dr. Nanda: Clinical Research Department, Family Health International, Box 13950, Research Triangle Park, NC 27709.
Drs. McCrory and Matchar: Center for Clinical Health Policy Research, Duke University Medical Center, First Union Tower, 2200 West Main Street, Suite 230, Durham, NC 27705.
Dr. Myers: Department of Obstetrics and Gynecology, Box 3279 Medical Center, Duke University Medical Center, Durham, NC 27710.
Dr. Bastian: Health Services Research and Development (152), Durham Veterans Affairs Medical Center, 508 Fulton Street, Durham, NC 27705.
Dr. Hasselblad: Department of Community and Family Medicine, Box 3850 Medical Center, Duke University Medical Center, Durham, NC 27710.
Mr. Hickey: School of Medicine, Duke University, Durham, NC 27710.