Participation in proficiency testing is required under the Clinical Laboratory Improvement Amendments of 1988. Although the primary purpose of this testing is evaluation of current laboratory performance, a major secondary benefit of such testing is postulated to be progressive improvement in laboratory performance over time as laboratories learn from their previous experiences and feedback.
To test the hypothesis that a secondary result of proficiency testing is improvement over time of laboratory performance.
The performance of participants in a large proficiency testing program (EXCEL), designed for clinic and office laboratories, on a specific problematic competence, the ability to differentiate group A streptococcus from group C streptococci, was monitored during a 6-year period (1996-2001) for changes in participant performance.
With each testing cycle, feedback on performance relative to peers and an educational discussion analyzing performance and suggesting best practices was submitted to participants.
Despite consistent feedback, there was no significant change in participant performance throughout the period studied.
In a large, stable proficiency testing program, a significant throat culture competence, which demonstrated less than optimal performance, did not improve over time, suggesting that current utilization of proficiency testing results in laboratory improvement programs is suboptimal.