Table 3.
Vitalograph standard equation | Equation based on present data | |||
---|---|---|---|---|
P-value | Change in lung age ± SE | P-value | Change in lung age ± SE | |
Dyspnea | <0.0001 | 6.5 ± 0.32 | <0.0001 | 5.8 ± 0.47 |
Smoker | <0.0001 | 5.7 ± 0.37 | <0.0001 | 6.3 ± 0.53 |
COPD | <0.0001 | 13.9 ± 0.94 | <0.0001 | 14.1 ± 1.30 |
Asthma | <0.0001 | 8.3 ± 0.64 | <0.0001 | 8.8 ± 0.91 |
Chronological age decile | <0.0001 | See Figure 2 | <0.0001 | See Figure 2 |
Height decile | <0.0001 | See Figure 2 | <0.0001 | See Figure 2 |
Cough | <0.0001 | 1.7 ± 0.34 | <0.0001 | 2.0 ± 0.49 |
Other airway disease | <0.0001 | 3.2 ± 0.69 | 0.0021 | 3.1 ± 1.00 |
Common cold | 0.0006 | 1.5 ± 0.45 | 0.0048 | 1.8 ± 0.65 |
Patient-reported allergies | 0.0052 | −0.9 ± 0.33 | 0.21 | −0.7 ± 0.46 |
Analyses were performed based on the equations used by the Vitalograph (“Vitalograph standard equation”) and the equation we have empirically derived in the subset of non-smokers not reporting any airway disease in this study (“equation based on present data”). Results are based on a selection procedure to identify predictors of high lung age using a multivariate linear model and shown as parameter estimates with SE and corresponding p-value. Parameter estimates are displayed in the sequence of inclusion into the model (based on F-tests). For categorical variables effects are relative to the respective control group of non-smoker, and absence of cough, allergies, COPD, asthma, dyspnea, or other airway disease. Note that the parameter estimates for chronological age and height are given for gender-specific deciles, respectively. Size of home town is not included because it did not reach the predefined threshold level of p < 0.15 for staying in the model. The parameter estimate for change in lung age is expressed in years.