A breakdown of the percentage of subjects below the lower limits of normal (LLN), including the agreement between the two models for each variable
| DLCO | DLNO | VA | |
| Number and percentage of the fitted data below the LLN (z score < –1.645) | |||
| GAMLSS | 60 (5.7%) | 81 (7.5%) | 54 (5.0%) |
| Segmented linear regression | 71 (6.6%) | 57 (5.3%) | 40 (3.7%) |
| Percentage below the LLN by age group | |||
| GAMLSS (5–49 years of age) (n=727) | 42 (5.8%) | 28 (3.9%) | 37 (5.1%) |
| GAMLSS (50–95 years of age) (n=349) | 18 (5.2%) | 33 (9.5%) | 17 (4.9%) |
| Segmented linear regression (5–49 years of age) (n=727) | 53 (7.2%) | 39 (5.4%) | 31 (4.3%) |
| Segmented linear regression (50–95 years of age) (n=349) | 18 (5.2%) | 18 (5.2%) | 9 (2.6%) |
| Agreement between the two models (Kappa statistic) | 0.67 [0.57 to 0.76] | 0.64 [0.54 to 0.74] | 0.58 [0.46 to 0.70] |
Agreement between models for each variable was determined by the Kappa statistic where 1 is less than the LLN and 0≥LLN. Strength of agreement: ≤0.20=none; 0.21–0.39=minimal, 0.40–0.59=weak; 0.61–0.80=moderate; ≥0.80–0.90=strong; ≥0.90 almost perfect.44 Brackets represent the 95% CI of the Kappa statistic.
DLCO, pulmonary diffusing capacity for carbon monoxide; DLNO, pulmonary diffusing capacity for nitric oxide; GAMLSS, generalised additive models of location, scale and shape; VA, alveolar volume.