[Swiss quality control in bacteriology and mycology 1989-1991]

Since 1983 there has been a voluntary quality assessment scheme (QAS) for bacteriology and mycology laboratories in Switzerland directed by the Committee for Quality Control of the Swiss Society for Microbiology. For the first time, the results of this QAS for the period between 1989 and 1991 are made available to a wider public. During the period in question, a steadily increasing number of participants received three samples containing microorganisms four times a year for identification and susceptibility testing. A mean percentage value of a point rating, with a maximum of 12 points, was calculated every year for each laboratory. Values of < or = 75% were defined as insufficient. For a first evaluation, laboratories were assigned to the categories of cantonal (and university) laboratories (C/U), private laboratories (P), and hospital laboratories (H, in hospitals which are neither university nor other tertiary care centres). Significant differences were detected between C/U and P on the one hand and H on the other. As a rule, H obtained poorer results than the two categories, examined fewer specimens, and their percentage with results < or = 75% was significantly higher. The second evaluation classified laboratories according to their recognition by the Swiss Federal Department of Public Health (FDPH). For statistical reasons, H had to be grouped with C/U. Nevertheless, their share of non-recognized laboratories was exceedingly high (15 out of 17 participants in 1991). Recognized laboratories constantly showed a better performance than non-recognized laboratories, examined more specimens, and their number of laboratories obtaining results < or = 75% was much lower.(ABSTRACT TRUNCATED AT 250 WORDS)