Agreement and differences between cotton tipped applicator and knife blade in isolated microbes subdivided according to presumed pathogenicity in the study population 2004−2014
| Agreement (95% CI) | Method difference | |||||||||
| Microbes isolated by both cotton tip and knife blade | Microbes isolated by cotton tip only | Microbes isolated by knife blade only | Total sum of plate readings negative by both cotton tip and knife blade | Kappa | Positive agreement | Negative agreement | Proportion positive by cotton tip | Proportion positive by knife blade | P value* | |
| Total | 99 | 81 | 18 | 7257 | 0.66 (0.60 to 0.72) | 0.66 (0.59to 0.74) | 0.99 (0.99 to 0.99) | 2.4% | 1.6% | 0.000001 |
| Probably pathogenic, authors’ definition† | 59 | 29 | 4 | 4878 | 0.78 (0.70 to 0.85) | 0.78 (0.67to 0.86) | 1 (0.99 to 1) | 1.8% | 1.3% | 0.000011 |
| Commensals, authors’ definition‡ | 40 | 52 | 14 | 2379 | 0.54 (0.44 to 0.63) | 0.55 (0.43 to 0.66) | 0.99 (0.98 to 0.99) | 3.7% | 2.2% | 0.000003 |
| Potential pathogens§ | 70 | 37 | 7 | 5566 | 0.76 (0.69 to 0.83) | 0.76 (0.66 to 0.84) | 1 (0.99 to 1) | 1.9% | 1.4% | 0.000005 |
| Normal flora¶ | 29 | 44 | 11 | 1691 | 0.50 (0.38 to 0.61) | 0.51 (0.38 to 0.63) | 0.98 (0.98 to 0.99) | 4.1% | 2.3% | 0.000009 |
*McNemar’s test.
†Probably pathogenic: Aggregatibacter segnis, Candida albicans, Corynebacterium macginleyi, Escherichia coli, Haemophilus influenzae, beta-hemolytic streptococci, Klebsiella oxytoca, Neisseria meningitidis, Moraxella catarrhalis, Fusarium spp., Pasteurella multocida, Streptococcus pneumoniae, Proteus mirabilis,Pseudomonas aeruginosa, Serratia marcescens, Serratia spp., Staphylococcus aureus, Staphylococcus lugdunensis, Stenotrophomonas maltophilia.
‡Commensals: Corynebacterium spp., except C. macginleyi, Gram-negative rod, coagulase-negative staphylococci, except S. lugdunensis, Micrococcus spp., Moraxella spp., mould unspecified, Pseudomonas spp., alpha-hemolytic streptococci.
§Potential pathogens17: A. segnis, C. albicans, C. macginleyi, E. coli, H. influenzae, beta-hemolytic streptococci, K. oxytoca, N. meningitidis, M. catarrhalis, Fusarium spp., P. multocida, S. pneumoniae, P. mirabilis, P. aeruginosa, S. marcescens, Serratia spp., S. aureus, S. lugdunensis, S. maltophilia, Gram-negative rod, Moraxella spp., Pseudomonas spp., alpha-hemolytic streptococci, mould unspecified.
¶Normal flora17: Corynebacterium spp. includes difteroides non-specified and C. macginleyi, Micrococcus spp., coagulase-negative staphylococci.