Table 4 

Sensitivity, specificity, PPV, and NPV for various predicted probabilities of COPD from logistic model 8 by diagnostic standard 

GOLD diagnostic standard (model 8) 



Modelbased predicted probability of COPD (95% CI) 



Performance characteristic (%) 
≥0.25 
≥0.50 
≥0.75 


Sensitivity 
90.9 (90.091.7) 
71.9 (70.673.2) 
35.7 (34.337.1) 
Specificity 
40.5 (39.241.9) 
73.5 (72.374.8 
92.2 (91.492.9) 
PPV 
58.2 (57.059.3) 
71.2 (69.972.5) 
80.7 (78.982.4) 
NPV 
83.0 (81.384.5) 
74.2 (72.975.4) 
61.1 (60.062.2) 


LLN diagnostic standard (model 8) 



Modelbased predicted probability of COPD (95% CI) 



Performance characteristic (%) 
≥0.25 
≥0.50 
≥0.75 


Sensitivity 
83.1 (81.984.4) 
59.8 (58.261.4) 
7.5 (6.68.4) 
Specificity 
55.9 (54.657.2) 
79.6 (78.680.6) 
98.8 (98.599.1) 
PPV 
54.1 (52.755.4) 
64.6 (63.066.3) 
80.1 (75.584.2) 
NPV 
84.2 (83.085.3) 
76.0 (75.077.1) 
63.1 (62.164.1) 


LLN, lower limit of normal; PPV, positive predictive value; NPV, negative predictive value 

Cooke et al. BMC Health Services Research 2011 11:37 doi:10.1186/147269631137 