Critical values in cytology.

The timely reporting of critical values, or values that may be life-threatening if immediate action is not taken, is essential to patient care and safety. Although some guidelines exist for critical diagnoses in cytology, not all laboratories have a specific list of diagnoses that should be considered critical, and the very existence of cytology "critical values" has been called into question. Here we propose a pragmatic system for determining cytology critical values and report our laboratory's critical value list, formulated based on a review of the medical literature regarding clinical urgency and other institutions' cytology critical value lists.