TABLE 2.
Medium lot, disk lot, and interlaboratory comparisons for nafithromycin disk diffusion testing results for S. pneumoniae ATCC 49619a
| Zone diam (mm) | No. of occurrences for medium lot: |
No. of occurrences for disk lot: |
No. of occurrences for laboratory: |
Total no. of occurrences | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | C | A | B | A | B | C | D | E | F | G | H | I | ||
| 22 | |||||||||||||||
| 23 | 2 | 1 | 1 | 2 | 2 | ||||||||||
| 24 | |||||||||||||||
| 25 | 2 | 5 | 5 | 7 | 5 | 2 | 5 | 3 | 1 | 1 | 12 | ||||
| 26 | 11 | 14 | 44 | 37 | 32 | 1 | 14 | 8 | 1 | 20 | 1 | 15 | 9 | 69 | |
| 27 | 57 | 52 | 49 | 77 | 81 | 13 | 37 | 19 | 6 | 18 | 8 | 3 | 34 | 20 | 158 |
| 28 | 43 | 54 | 40 | 67 | 70 | 31 | 7 | 14 | 10 | 17 | 19 | 7 | 9 | 23 | 137 |
| 29 | 43 | 36 | 21 | 52 | 48 | 14 | 11 | 17 | 2 | 25 | 23 | 1 | 7 | 100 | |
| 30 | 19 | 14 | 14 | 23 | 24 | 1 | 1 | 15 | 6 | 24 | 47 | ||||
| 31 | 4 | 2 | 4 | 5 | 5 | 7 | 3 | 10 | |||||||
| 32 | 1 | 3 | 1 | 3 | 4 | 4 | |||||||||
| 33 | |||||||||||||||
| 34 | |||||||||||||||
| 35 | |||||||||||||||
| 36 | |||||||||||||||
| 37 | |||||||||||||||
| 38 | 1 | 1 | 1 | 1 | |||||||||||
| Total | 180 | 180 | 180 | 270 | 270 | 60 | 60 | 60 | 60 | 60 | 60 | 60 | 60 | 60 | 540 |
| Median | 28 | 28 | 27 | 28 | 28 | 28 | 27 | 27 | 29 | 27 | 29 | 29 | 27 | 27.5 | 28 |
| Mode | 27 | 28 | 27 | 27 | 27 | 28 | 27 | 27 | 29 | 26 | 29 | 30 | 27 | 28 | 27 |
| Geometric mean | 28.0 | 27.9 | 27.4 | 27.7 | 27.8 | 28.0 | 26.8 | 27.2 | 29.2 | 26.9 | 28.6 | 29.3 | 26.9 | 27.4 | 27.8 |
| Range | 8 | 8 | 16 | 9 | 16 | 5 | 4 | 8 | 7 | 5 | 13 | 5 | 5 | 5 | |
a
The all-laboratory-medians approach of Gavan et al. (10) was used to calculate the proposed QC range of 25 to 31 mm (in boldface type) (all-laboratory median, 28 mm; median of ranges, 5 mm; one-half median of ranges rounded up, 3 mm); 98.7% (533/540) of all qualified results were within the proposed QC range of 25 to 31 mm.