Univariate associations between unnormalised and normalised radiological parameters, St George's Respiratory Questionnaire (SGRQ) total score and BODE
| Unnormalised parameter estimate (95% CI) | Normalised parameter estimate (95% CI) | p Value† | |
| SGRQ* | |||
| Emphysema, % | 0.53 (0.45 to 0.61) | 5.82 (4.91 to 6.72) | <0.001 |
| Segmental wall thickness, mm | 8.72 (2.91 to 14.53) | 1.95 (0.65 to 3.25) | 0.003 |
| Segmental wall area, % | 1.96 (1.57 to 2.35) | 6.27 (5.02 to 7.52) | <0.001 |
| Pi10 | 56.28 (46.91 to 65.64) | 7.20 (6.00 to 8.40) | <0.001 |
| BODE* | |||
| Emphysema, % | 1.02 (1.02 to 1.02) | 1.23 (1.20 to 1.26) | <0.001 |
| Segmental wall thickness, mm | 1.10 (0.93 to 1.29) | 1.02 (0.99 to 1.06) | 0.27 |
| Segmental wall area, % | 1.03 (1.02 to 1.05) | 1.11 (1.07 to 1.16) | <0.001 |
| Pi10 | 2.20 (1.66 to 2.91) | 1.11 (1.07 to 1.15) | <0.001 |
↵* For SGRQ models, parameter estimate is the increase in SGRQ score for a 1 unit increase in unnormalised radiological parameter. For BODE models, parameter estimate is the fold increase in BODE index score for a 1 unit increase in the unnormalised radiological parameter. All models are adjusted for scanner type. For normalised radiological parameters, airway disease measures and emphysema values have been scaled and centred as follows: (value – mean)/SD. Hence a 1 unit increase in a normalised measure is 1 SD.
↵† p Value for significance of parameter estimate in the model which is identical for unnormalised and normalised estimates.
Pi10, 10 mm lumenal perimeter.