First author [ref.] | Subjects n | Subject type | Measurements n | Basal potential p-value | Δ amiloride p-value | Δ low chloride + isoproterenol p-value | Statistic |
When NPD measurements are repeated in patients with CF, non-classic CF or questionable CF, the mean results per group do not differ | |||||||
Vermeulen [38] | 14 | CF (floor) | 2 | ND | NS | NS | Wilcoxon |
16 | CF (turbinate) | 2 | ND | NS | NS | ||
Jaron [39] | 17 | Questionable CF | 2 | NS | NS | NS | Paired t-test |
Yaakov [40] | 25 | CF | 2 | NS | NS | 0.07 | Paired t-test |
43 | Non-classic CF | 0.008 | NS | NS | |||
When NPD measurements are repeated in patients with CF, non-classic CF, questionable CF or non-CF, the individual “diagnostic” conclusion remains the same but the intra-patient variability for individual NPD parameters is considerable | |||||||
Middleton [41] | 6 | CF | ≥4 | 7.5 | ND | 1.5 (low chloride only) | Within subject sd BA limits of agreement R and L nostril difference (mean difference ±2×sd) |
6 | Non-CF | ≥4 | 2.1 | ND | 3.3 (low chloride only) | ||
46 | CF | 2 | 18.8, -9.8 mV | 10.3, -15.3 mV | 3.1, -4.1 mV | ||
40 | Non-CF | 2 | 11.2, -10.4 mV | 7.6, -7.2 mV | 14.0, -23.6 mV | ||
Vermeulen [38] | 14 | CF (floor) | 2 | ND | ND | 10.2, -11.5 mV | BA limits of agreement (mean difference ±2×sd) |
16 | CF (turbinate) | ND | ND | 11.5, -12.7 mV | |||
34 | Non-CF (floor) | 21.9, -19.0 mV | |||||
38 | Non-CF (turbinate) | 17.4, -20.2 mV | |||||
Yaakov [40] | 25 | CF | ≥2 | ND | ND | 7, -10 mV | BA limits of agreement (mean difference ±2×sd) |
43 | Non-classic CF | ND | ND | 12, -12 mV | |||
Ahrens [42] | ±10 | CF | 9 | 6.0, 8.5 | 7.5, 11.4 | 3.5, 9.3 | Within subject sd (min. and max. for 4 sites estimated from fig. 1) |
Delmarco [43] | 35 | CF | 2 | 6.4 % | ND | ND | CV |
18 | Questionable CF | 10.5 % | ND | ND | |||
16 | Non CF | 9.5 % | ND | ND | |||
Hofmann [44] | 14 | CF (subcutaneous) | 2 (3 min) | r=0.97, p<0.05, variation 3.9% | ND | ND | Not reported |
2 (>1 month) | r=0.78, p<0.05, variation 11.3% | ND | ND | ||||
82 | CF (epicutaneous) | 2 (3 min) | r=0.92, p<0.05, variation 4.3% | ND | ND | ||
2 (>1 month) | r=0.73, p<0.05, variation 14.3% | ND | ND | ||||
Alton [45] | 7 | Non-CF | 6 (7 weeks) | 16% | ND | ND | CV |
CF: cystic fibrosis; ND: no data; NS: nonsignificant; BA: Bland–Altman; R/L: right/left; CV: coefficient of variation.