Parameter estimates for the course of decline of per cent predicted forced vital capacity from onset of disease (Model 1)
| Parameter | Significance of parameter | Overall cohort | |
| Mean (se)# | 95% CI | ||
| b1 % | Initial vital capacity | 100.3 (3.8) | 92.8, 107.9 |
| b2 % | Decline from initial vital capacity | −74.1 (4.6) | −83.2, −65.0 |
| b3 months | Midpoint between initial and final vital capacity (from disease onset) | 17.2 (1.5) | 14.3, 20.2 |
| b4 months | Timescale factor representing rapidity of decline | 13.3 (1.1) | 11.2, 15.4 |
| b1+b2 % | Final vital capacity | 26.2 (2.1) | 22.1, 30.4 |
#: p<0.001 for all parameter estimates, indicating that all four parameters contributed significantly to the per cent predicted forced vital capacity.