Table 5. Lung function (FEV1) decline in participants with and without airflow obstruction (postBD FEV1/FVC<LLN), means and standard deviation (SD) or 95%CI.
| Variables | NO COPD (N = 2,025) |
SD (or 95%CI) |
COPD (N = 95) |
SD (or 95%CI) |
P-value* |
|---|---|---|---|---|---|
| Mean decline PreBD (mL/year) | -34.2 | 43.8 | -26.1 | 48.9 | 0.08 |
| Mean decline PostBD (mL/y) | -35.9 | 40.7 | -26.8 | 41.3 | 0.04 |
| Mean decline PreBD (%P/year) | -0.21 | 1.8 | -0.17 | 2.1 | 0.90 |
| Mean decline PostBD (%P/year | -0.22 | 1.6 | -0.14 | 2.0 | 0.60 |
| Mean decline PreBD (%B/year) | -1.26 | 2.2 | -1.30 | 2.8 | 0.90 |
| Mean decline PostBD (%B/year), | -1.32 | 1.5 | -1.36 | 2.1 | 0.80 |
| % with >20 mL/y increase in preBD FEV1 | 5.9 | 4.9–7.0 | 7.4 | 2.0–12.7 | 0.56 |
| % with >20 mL/y increase in postBD FEV1 | 5.7 | 4.7–6.7 | 9.9 | 3.6–16.1 | 0.10 |
| % with any preBD FEV1 decline | 84.5 | 82.8–86.2 | 77.9 | 69.6–86.2 | 0.08 |
| % with any postBD FEV1 decline | 86.0 | 84.5–87.5 | 80.2 | 72.4–88.0 | 0.12 |
| % with any preBD decline as %P | 55.8 | 53.4–58.2 | 54.7 | 44.7–64.8 | 0.84 |
| % with any postBD decline as %P | 57.7 | 55.5–59.9 | 57.1 | 46.8–67.5 | 0.91 |
| % with>40mL/y decline | 41.0 | 38.7–43.3 | 32.6 | 23.1–42.2 | 0.11 |
| % with>40mL/y postBD | 42.7 | 40.4–45.1 | 38.5 | 28.6–48.3 | 0.4 |
| % with preBD decline >3%P/y | 4.9 | 4.0–5.9 | 8.4 | 2.7–14.1 | 0.13 |
| % with postBD decline >3%/y | 4.3 | 3.4–5.2 | 3.2 | 0.0–6.7 | 0.59 |
| % with preBD decline >4%B/y | 5.5 | 4.5–6.5 | 16.8 | 9.2–24.5 | <0.001 |
| % with postBD decline >4%B/y | 4.1 | 3.2–5.0 | 7.4 | 2.0–12.7 | 0.13 |
preBD = before bronchodilator use; postBD = after bronchodilator use; COPD is a postBD FEV1/FVC<lower limit of normal according to the PLATINO reference values.
*T test for independent groups or Fisher exact test for categorical variables; %P = FEV1 expressed as percentage of predicted by the PLATINO reference values; %B = FEV1 expressed as percentage of baseline or first measurement; Results based on 2,120 individuals with two preBD spirometric tests, or 2,026 individuals with two postBD spirometry tests.