TABLE 5.
Gatifloxacin disk diffusion quality control result for H. influenzae ATCC 49247 from a nine-laboratory trial (10)
| Gatifloxacin 5-μg disk zone diameter (mm) | No. of occurrences for laboratory:
|
Total no. of occur-rencesa | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| A | Bb | C | D | E | F | G | H | I | ||
| 32 | 1 | 1 | ||||||||
| 33a | 2 | 6 | 2 | 10 | ||||||
| 34a | 12 | 8 | 4 | 1 | 25 | |||||
| 35a | 1 | 26 | 12 | 3 | 2 | 6 | 14 | 64 | ||
| 36a | 4 | 10 | 13 | 16 | 8 | 13 | 16 | 17 | 97 | |
| 37a | 5 | 23 | 7 | 11 | 8 | 16 | 9 | 26 | 105 | |
| 38a | 4 | 14 | 6 | 10 | 24 | 11 | 2 | 71 | ||
| 39a | 18 | 12 | 12 | 11 | 5 | 8 | 66 (54) | |||
| 40a | 17 | 17 | 20 | 2 | 56 (39) | |||||
| 41a | 9 | 13 | 1 | 23 (10) | ||||||
| 42 | 3 | 11 | 1 | 15 (4) | ||||||
| 43 | 3 | 3 (0) | ||||||||
| 44 | 4 | 4 (0) | ||||||||
| Total | 60 | 60 | 60 | 60 | 60 | 60 | 60 | 60 | 60 | 540 (480) |
a
The proposed quality control range calculated as the median ± 0.5 × the average zone range = 37 ± 3 mm, or 34 to 40 mm (10). This range contains only 94.8% of the generated zone diameters from qualifying sites and was expanded to 33 to 41 mm. Numbers in parentheses are the numbers of occurrences after deletion of results from laboratory B.
b
Results from laboratory B results were omitted because this site’s median zone diameter varied significantly from those of the other participants.