Table 2

Distributions of the D-12, CAT and E-RS total scores

D-12 score (0–36)CAT score (0–40)E-RS Total score (0–40)
MeanMedianSDMax.Floor effect (%)MeanMedianSDMax.Floor effect (%)MeanMedianSDMax.Floor effect (%)
All subjects0.20.00.66.084.04.33.03.925.014.61.20.01.915.053.3
Healthy non-smoking subjects*†0.20.00.56.086.53.63.03.324.015.90.90.01.610.062.5
COPD defined by fixed ratio0.30.00.84.081.24.84.04.119.015.31.61.02.212.044.7
Non-COPD smokers0.20.00.56.082.04.84.04.125.013.11.51.02.115.046.5
Non-COPD never smokers0.20.00.56.086.73.63.03.424.016.30.90.01.612.062.7
COPD defined by LLN0.50.01.04.073.56.26.04.819.014.71.81.52.19.038.2
Non-COPD smokers0.20.00.56.082.24.84.04.125.013.01.51.02.115.046.6
Non-COPD never smokers0.20.00.66.086.83.63.03.424.016.50.90.01.610.062.7
  • *FEV1 of >85% predicted and FEV1/FVC of >0.7.

  • †A smoking history of <1 pack-year. Numbers in parentheses indicate the theoretical score range, and higher scores indicate worse status.

  • CAT, COPD assessment test; COPD, chronic obstructive pulmonary disease; D-12, Dyspnoea-12; E-RS, evaluating respiratory symptoms in COPD; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LLN, lower limit of normal.