College of American Pathologists
Printable Version

  PAP/NGC Program Review





cap today

May 2002
Feature Story

Before litigation, blinded
rescreening a must
CAP updates guide for review of Pap tests in litigation or potential litigation

CAP Guidelines for Review of Pap Tests in the
Context of Litigation or Potential Litigation

Emily E. Volk, MD
R. Marshall Austin, MD, PhD

The CAP Board of Governors approved in November 2001 an updated version of its 1998 Guidelines for Review of Pap Tests in the Context of Litigation or Potential Litigation.

The updated version includes strengthened wording that says, "One asserting a violation of the standard of care should first have the Pap test slides assessed by qualified reviewers without knowledge of clinical background and in an environment that simulates the normal screening practice. Specifically, such slides should be subjected to an unbiased screening process that includes the contested case material as one or more of a substantial number of normal and abnormal gynecologic cytology samples." Having several qualified reviewers conduct the review is the best process, the guidelines say, and unless the blinded reviewers find consistently that the laboratory failed to identify clinically significant abnormalities, negligence should not be inferred. The full text of the guidelines appears below.

The growing legal threat that many cytology professionals now face in North America may be directly related to the Pap test's unique effectiveness as a screen for cervical cancer in the second half of the last century. The test's overwhelming success and the subsequent high expectation of its performance has led to harsh judgment by the public, lay press, and juries of anything less than eradication of cervical cancer in screened populations.

To curb the negative medicolegal tide engulfing cytology professionals, the CAP has adopted the guidelines for the review of Pap tests in litigation and potential litigation. These guidelines attempt to remove some of the bias that naturally accompanies expert witness review, while providing guidance to potential expert witnesses. In effect, the guidelines require ethical plaintiffs' experts to first provide unbiased documentation of unreasonable screening and interpretation of Pap tests before asserting in formal reports that a standard of practice has been violated.

Durable evidence such as Pap test slides and mammograms have always been subjected to "hindsight bias" wherein the knowledge of an unfavorable outcome (cancer) inevitably colors the review and interpretation of the durable evidence. Even grossly unreasonable retrospective interpretations may appear reasonable to a lay jury in the face of an unfavorable clinical outcome. The blinded screening test attempts to adjudicate the question of reasonableness of the original review by using a form of unbiased peer review that is fair to the laboratory and to the injured patient.

The updated CAP version mirrors another slightly earlier version of the Pap litigation guidelines passed by the Executive Board of the American Society of Cytopathology on Nov. 10, 2000. The ASC guidelines similarly advise, "A violation of a reasonable prudent practitioner standard of practice based on how specific Pap test slides were screened and interpreted can only be established through an unbiased blinded rescreening review process that includes the contested case as one of a number of Gyn cytology samples representing a variety of disease states." The American Society of Cytopathology guidelines can be found on the ASC Web site (

A major challenge for the profession now is how to educate cytopathology experts and ensure that they adhere to the guidelines—that is, rely on the unbiased prelitigation test of multiple-slide blinded rescreening rather than on previously prevalent biased retrospective reviews. The cytology school of the Medical University of South Carolina has the largest experience with the recommended unbiased blinded-review method. It has been applied to about 100 litigated Pap cases under the supervision of Blair Holladay, PhD. For information on the program, call the Medical University of South Carolina Center for Quality Improvement in Gynecologic Cytology (843-442-1724).

The updated CAP guidelines attempt to establish a reasonable, objective, and fair method for reviewing Pap tests in the context of litigation or potential litigation that is representative of the day-to-day practice of cytology in North America. In doing so, the CAP may help prevent unreasonable and confused public expectation and expert witness testimony from causing further attrition from the cytology profession.

1.  Frable WJ, Austin RM, Greening SE, et al. Medicolegal affairs: IAC Task Force summary. Acta Cytologica. 1998;42: 76-132.
2.  Frable WJ. Guidelines for experts reviewing Papanicolaou smear litigation cases. Arch Pathol Lab Med. 1997;121: 331-334.
3.  Austin RM. Results of blinded rescreening of Papanicolaou smears versus biased retrospective review. Arch Pathol Lab Med. 1997;121:311-314.
4.  Fitzgibbons PL, Austin RM. Expert review of histologic slides and Papanicolaou tests in the context of litigation or potential litigation. Arch Pathol Lab Med. 2000;124: 1717-1719.

Dr. Volk is staff pathologist at St. John Hospital and Medical Center in Detroit. Dr. Austin is medical director and director of cytopathology and gynecologic pathology services for Coastal Pathology Laboratories, Charleston, SC. Both are members of the CAP Cytopathology Committee.