negative predictive value


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Related to negative predictive value: specificity, Negative Likelihood Ratio

negative predictive value

A numerical value for the proportion of individuals with a negative test result who are free of the target condition—i.e., the probability that a person who is a test negative is a true negative.

neg·a·tive pre·dic·tive val·ue

(neg'a-tiv prē-dik'tiv val'yū)
The probability of a negative test result indicates the absence of an analyte or a specific disease.

negative predictive value

The proportion of people whose test results are true negatives and who are truly disease free.
References in periodicals archive ?
Graph 1: Evaluation of Modified Alvarado Scoring in diagnosing Acute Appendicitis Sensitivity 97.4 Specificity 79.3 Positive Predictive Value 92.7 Negative Predictive Value 92 Diagnostic Accuracy 92.5 Negative Laparotomy Rate 7.3 Note: Table made from bar graph.
There were two primary endpoints of this study, one was to determine the sensitivity and specificity of CRP against blood culture to determine the neonatal sepsis and secondary end-point was to determine the negative predictive value of CRP in determining the duration of antibiotics in neonates presenting with sepsis.
High positive predictive value of MASS means a score of 7 or more of MASS strongly suggests acute appendicitis and negative predictive value shows that MASS less than 7 is in favor of absence of acute appendicitis in most of the patients, this group of patients can be observed for some time, reassessed, further investigated and then can be operated upon or discharged.
[sup][19] Consequently, it is necessary to find a method with high negative predictive value so that unnecessary diagnostic tests could be avoided.
A method is diagnostically acceptable only when its diagnostic indicators (sensitivity, specificity, positive predictive value, and negative predictive value) have values greater than 80%10.
(1,3-5,7-11) These reference values are critically important as they are used to score laboratory performance; in multitissue samples, such as TMAs, they can be used to calculate agreement rates, test sensitivity, specificity, positive predictive value, negative predictive value, and [kappa] values.
The key study finding was that an early response proved to have a 69% positive predictive value and a 76% negative predictive value for significant improvement in symptoms at 12 weeks as defined by at least a 30% improvement in PANSS total score, compared with baseline.
They found that response of the tumour to treatment with PET-CT had a sensitivity (rate of true positives) of 83 percent, specificity (rate of true negatives) of 54 percent, positive predictive value (probability that patients who test positive have the disease) of 31 percent and negative predictive value (probability that patients who test negative do not have the disease) of 92 percent.
In conclusion, when using the four-detector row, the negative predictive value of CT findings in patients with clinically suspected PE and positive D-dimer is low.
The fetal fibronectin (fFN) assay has attracted interest because of its reported high negative predictive value for preterm labor.
For patients with an average risk of having streptococcal pharyngitis, a number of testing strategies can rule out infection, including a single negative rapid strep antigen test, which has a negative predictive value of more than 95%.
Skin prick tests have excellent sensitivity and negative predictive value, but variable specificity and positive predictive values; therefore skin tests, particularly when performed with fresh foods, can reliably exclude food allergies when negative, but cannot confirm food allergy when positive (Bock et al.

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