Results of blinded rescreening of Papanicolaou smears versus biased retrospective review.

Abstract

Review of Papanicolaou smear cases that are the focus of litigation typically takes place in a biased setting with foreknowledge of an adverse patient outcome (outcome bias) or litigation and with more time allotted for slide review than is available in normal screening situations. Factors that normally mitigate against overly aggressive slide interpretation, such as concern about false-positive diagnoses and possible unnecessary surgical procedures and expense, are absent. This results in a tendency toward overly aggressive interpretation of questionable or uncertain cytologic abnormalities. These factors can be minimized by a variety of blinded slide review formats with the goal of simulating normal, on-the-job, prospective screening as in actual practice. Despite some limitations, blinded rescreening can provide valuable insight into the relative degree of difficulty involved in interpreting specific slides. The difficulty of a case in question is arguably the second most important factor, after assessment of overall laboratory performance, in determining whether a reasonable standard of practice has been followed.