Sentence examples for because the reference test from inspiring English sources
Verification bias might be present when reference testing is conducted only selectively, because the reference test is considered too expensive or too invasive.
The imperfect gold standard bias was present in all studies, because the reference test was a combination of colposcopy and histology.
Although the in-house ELISA in our study had an acceptable diagnostic sensitivity of 95.6% (cut-off = 0.18), the diagnostic accuracy of this ELISA and also of the WB assays established in this study were not as expected, because the correspondence with the reference test was <90%.
Moreover, the risk for misclassification by DFM diminishes the apparent value of Tp-PCR when DFM is the reference test because samples from syphilis patients that yield a negative DFM result, but a positive Tp-PCR result, are currently considered false-positive.
Or when only subjects with symptoms of GERD such as vomiting are tested with a reference test, because of ethical considerations (i.e. the reference test is considered to be too invasive [ 9]).
Second, selection of patients with a negative reference test result as 'controls' may lead to inclusion of controls that correspond to a different clinical domain, i.e. patients who underwent the reference test but not necessarily because they were similarly suspected of the target condition [ 16, 17].
However, because microscopy is the most commonly used test in practice and is often used as the reference test in studies, we selected it for use as the reference standard within this review to detect S. haematobium and S. mansoni.
Tp-PCR is clinically useful for testing of ulcers or skin lesions in areas where syphilis prevalence is high (4 ), but uncertainties remain because of the variability in the reference tests used in the different diagnostic studies.
Finally, the validity of these findings is uncertain because the reference standard test for illness severity was the unverified final diagnoses made by the treating physicians and not standard, microbiologically based definitions.
