Table. 1—

Sensitivity(Sens), specificity (Spec) and positive predictive value (PPV) of different operational definitions of asthma, as compared with “ever asthma” and with bronchial hyperreactivity

nPrev %Ever asthmaBronchial hyperreactivity#
 Wheeze, breathlessness1209110.480.920.450.310.930.29
 Wheeze, breathlessness, no cold80870.380.950.530.240.950.33
Bronchial hyperresponsiveness
 Slope >25%2815250.640.780.26
 >20% at 1 mg1538140.520.900.38§§§
 Slope >10%1129100.420.930.42
Wheeze and BHR#
 Wheeze, BHR7256.40.400.960.62
 Wheeze, breathlessness, BHR4814.30.320.980.75§§§
 Wheeze, breathlessness, no cold, BHR3663.20.260.990.81
ECRHS definition+
 Any 1 of 3 variables8497.50.250.950.34
 Any 2 of 3 variables2862.5§§§0.140.990.99
 All 3 variables1171.
 Any 1 of 8 questions371932.90.600.710.18
 Any 2 of 8 questions167914.90.400.890.27
 Any 3 of 8 questions9378.30.280.950.34
 Any 4 of 8 questions5384.8§§§0.200.980.98
 Any 5 of 8 questions3443.00.150.990.50
 Any 6 of 8 questions2121.90.110.990.56
 Any 7 of 8 questions1151.
 All 8 questions430.
  • Data are presented as n, unless otherwise stated. Prev: prevalence; BHR: bronchial hyperresponsiveness; ECRHS: European Community Respiratory Health Study. #: >20% fall in FEV1 at 1 mg; : theoretical PPV, if true prevalence of asthma 10%; +: woken by shortness of breath, attack of asthma or asthma medication; §: part of the definition.