Table 2 The best cut-off values of age and pack-years and their combination to detect asthma–COPD overlap syndrome among 190 asthmatics with positive smoking history

From: Prevalence of asthma–COPD overlap syndrome among primary care asthmatics with a smoking history: a cross-sectional study

  Sensitivity
(%)
Specificity
(%)
PPV
(%)
NPV
(%)
Age 60 years 63.5 59.4 37.1 81.2
Pack-years 20 80.8 42.8 34.7 85.5
Age 60 years or pack-years 20 90.4 27.5 32.0 88.4
Age 60 years and pack-years 20 53.8 74.6 44.4 81.1
  1. Abbreviations: COPD, chronic obstructive pulmonary disease; NPV, negative predictive value; PPV, positive predictive value.