TABLE 1.
COMPOSITE PULMONARY FUNCTION AND RESPIRATORY MUSCLE STRENGTH
| Variable | Continuous Value Achieving z Score | |
|---|---|---|
| z Score = 0 | z Score = 1 | |
| Pulmonary function | ||
| FVC, L | 1.88 | 2.51 |
| PEF, L/min | 258 | 371 |
| FEV1, L | 1.61 | 2.18 |
| Respiratory muscle strength | ||
| Maximal inspiratory pressure, mm H2O | 41 | 62 |
| Maximal expiratory pressure, mm H2O | 66 | 92 |
The composite pulmonary function measure was constructed by converting the raw score from the three spirometric measures (FVC, PEF, and FEV1) to z scores using the mean and standard deviation from all participants at baseline. The values in the table are approximations to the underlying measures that correspond to average performance at baseline (z = 0) and 1 SD better than average (z = 1). A similar procedure was employed to construct composite respiratory muscle strength based on MIP and MEP measures.