SPADA

Test parameters

• Sensitivity: – the ability to identify as positive all those with the disease • Specificity: – the ability to identify as negative all those without the disease • Predictive value positive (PV+): – the proportion of true positives among those testing positive • Predictive value negative (PV-): – the proportion of true negatives among those testing negative

Disease

present

absent

PV+ = a/ (a+b)

total

PV- = d/ (c+d)

a=true positives

b=false positives

Test result

POS

a+b

d=true negatives

c=false negatives

NEG

c+d

TOT

a+c

b+d

Sensitivity = a/ (a+c)

Specificity = d/ (b+d)