If the presence of an alternative diagnosis is to be used as justification for discontinuing SARS-specific isolation precautions, the alternative diagnoses should be based only upon tests with high
positive predictive value, and the clinical illness should be fully explainable by the diagnosis.
Although the presence of symptoms was statistically associated with T vaginalis infection, the
positive predictive value was low (0.20).
Statistical Indices of Oval Shape Sensitivity 0% Specificity 76%
Positive predictive value 0% Negative predictive value 44% Table 3.
Prediction of Appendicitis by Modified Alvarado Score in Study Group if Score is [greater than or equal to] 7 Sensitivity 90.4% Specificity 81.25%
Positive Predictive Value 96.20% Negative Predictive Value 61.9% Disease Prevalence 84% Negative Appendectomy Rate 3.79% Table VI.
Both had poor sensitivity and
positive predictive values.
The swab collection method was 55% sensitive, 63% specific, and had a
positive predictive value of 62% and an overall test efficiency of 63%.
Sensitivity of Typhidot was 88.5% (CI 69.82-97.42), specificity was 81.56% (74.16-87.58),
positive predictive value was 46.94% (32.54-61.720 and negative predictive value was 97.46% (92.74-99.44).
"All of these had good
positive predictive values, indicating that a pregnancy had a good chance of surviving," she said, "but the negative predictive values were not useful for clinical practice or research."
The assay had a specificity of 96%, a
positive predictive value of 88%, a negative predictive value of 97%, and an accuracy rate of 95% compared with culture.
Overall, the
positive predictive value ranged from 0% to 67%, and the negative predictive value ranged from 71% to 100%.
These tests should be sensitive enough to reject all contaminated donations but specific enough to achieve a strong
positive predictive value and minimize unnecessary deferral of otherwise acceptable donors.
*
Positive predictive value = the percentage of correctly predicted difficult intubations as a proportion of all predicted difficult intubations.