Survey of special practices associated with College of American Pathologists proficiency testing in the Commonwealth of Pennsylvania.

A questionnaire concerned with special practices associated with proficiency testing was sent to the Chemistry Supervisor, Hematology Supervisor, and Chief Pathologist of 190 Pennsylvania hospital laboratories. Responses were received from 156 hospitals (82.1%) and included responses from 131 chemistry supervisors, 108 hematology supervisors, and 92 chief pathologists. The vast majority of respondents (85% to 95%) indicated moderate to great pressure to score acceptably. The survey showed a high prevalence of special practices, including analysis of controls just prior to survey specimens (23% to 42%), analysis in duplicate on a single instrument (52% to 88%), analysis on more than one instrument (17% to 31%), analysis on two or more separate days (20% to 39%), and delay of testing until an instrument is "working better" (24% to 34%). Approximately 63% of chemistry results and 72% of hematology results are reported as averages or medians. Pathologists consistently reported a lower prevalence of special practices than did laboratory supervisors. These high prevalences of special practices associated with proficiency testing specimens have important implications for proficiency testing programs.