Quality improvement of diagnostic microbiology through a peer-group proficiency assessment program. A 20-year...

To evaluate the microbiology laboratory performance in Ontario over a 20-year period of participation in a quality assessment program and to assess the impact of quality improvement strategies.

Longitudinal review of isolation, identification, and antimicrobial susceptibility testing of bacteria from lyophilized, simulated patient samples.

Ontario medical laboratories, licensed by the Ministry of Health, have been subjected to mandatory testing by the Laboratory Proficiency Testing Program of the Ontario Medical Association since 1974. Survey reports, information bulletins, correspondence, on-site consultations, educational assistance tutorials, and teleconference education are used as quality improvement strategies.

Laboratories were subjected annually to 20 external quality assessment challenges. Performance was assessed against consensus reference values. Single survey and cumulative profiles were reviewed by a peer-group panel for acceptable or unacceptable performance. Specific interventions are used to improve collective and individual laboratory performance.

The number of microbiology laboratories declined from 335 in 1974 to 190 in 1994. Twenty-one percent failed expected performance standards on initial review. One hundred forty-two on-site consultations and 61 educational assistance tutorials have been provided. Twenty-five laboratories were declared nonproficient. Since 1989, 50% of the laboratories have scored at or above 80% for isolation and identification, but 25% have scored at or below 50% on susceptibility testing, and 10% or fewer have scored at or above 80%. Poor susceptibility testing performance is due to inappropriate agent selection, not testing errors.

The emphasis of the Laboratory Proficiency Testing Program is on quality improvement, not punishment. Performance has improved, but poor performers have the same characteristics as in 1974. Identification to species is common owing to the use of commercial systems. Automated susceptibility testing has increased to 45% of participants.