Statistics - explanations and formulas

Specificity and Sensitivity

Sensitivity - SnOut (Sensitivity rules Out dz) – so a high sensitivity tells us if the test is negative, we can believe that the patient doesn’t have the disease.

114/114+22=0.84

 

Specificity - SpIn (Specificity rules In disease) – so a high specific test tells us that if the test is positive, we can believe the patient has the disease (or in this case, IPV)

51/18+51=0.70

The equations were taken from: Asciutto KC, Ernstson A, Forslund O, Borgfeldt C. Self-sampling with HPV mRNA analyses from vagina and urine compared with cervical samples. J Clin Virol. 2018 Apr;101:69-73. doi: 10.1016/j.jcv.2018.02.002. Epub 2018 Feb 6. PMID: 29433016.