Denominator of negative predictive value is: (A) TP + FP, (B) TP + FN, (C) TN + FN, (D) TN + FP
Answer is C. Predictive value reflects the diagnostic power of the test. It&;s accuracy depends on sensitivity, specificity and disease prevalence. Predictive value of a negative test = d/(c+d)x100 Ref: 25th edition, Park&;s Textbook of Preventive and Social Medicine, Page no. 152