Detection procedure in a 2‐yr monitoring programme in the Dutch Detection, Intervention and Monitoring of COPD and Asthma in family practice (DIMCA) study
| Group | Criteria |
| 1st group: subjects with persistently reduced lung function or increased BHR# | Two out of four measurements during the first 6 months: FEV1 ≤FEV1 pred minus 2 sd, and/or PC20 <2 mg histamine·mL−1 and FEV1-reversibility ≥15% |
| 2nd group: subjects with a rapid decline of lung function with signs of BHR¶ | A decline in FEV1 >80 mL·yr−1 in 1 yr of monitoring, and a PC20 ≤8 mg histamine·mL−1, and/or FEV1-reversibility ≥10% |
| 3rd group: subjects with a moderate increase in the decline in lung function or signs of BHR | A decline in FEV1 between 40–80 mL·yr−1 during 2 yrs of monitoring, and a chronic productive cough for at least 3 months·yr−1, and/or at least one exacerbation·yr−1 |
FEV1: forced expiratory volume in one second
PC20: provocative concentration causing a 20% fall in FEV1
pred: predicted
BHR: bronchial hyperresponsiveness
#: Once identified, these subjects were withdrawn from monitoring
¶: in these groups ethical considerations prompted intervention