Beoordeling van de artikelen met QUADAS-2

Guideline for the diagnosis of NERD: methodological quality of included in vitro studies (QUADAS-2)

Author, year	Type of test	Data collection	Patient recruitment method	Blinding	Adequate description of reference standard	Avoidance of differential bias	Avoidance of partial verification bias	Funding
Kowalski ML, 2005¹	15-HETE generation assay (AspiTest)	Retrospective	Not reported	No	No	No	Yes	Not reported
Bavbek S, 2009 (CAST)	CAST	Prospective	Not reported	No	Yes	No	Yes	Scientific Research Project (2006-08-09-227)
Bavbek S, 2009 (BAT)	BAT (CD63), BAT (CD203)	Prospective	Not reported	No	Yes	No	Yes	Scientific and Technological Research Council of Turkey TUBITAK, SBAG-HD-17
Celik G, 2009	BAT (CD63), BAT (CD69), BAT (CD203c)	Not reported	Not reported	No	No	No	No	NIH Grants AI143654F, RO1A142221, TUBITAK, TUBA-GEBIP.
Sanak M, 2004	LTE4 CysLT; PGs: E2, F2a, 9a11bF2; iso-F2	Not reported	Not reported	No	Yes	Yes	Yes	Not reported
Celejewska-Wojcik N, 2012	LTE4	Prospective	Consecutive	No	Yes	Yes	Yes	PSPB-072/2010 grant
Yamaguchi H, 2011	LXA4, 15-epi-LXA(4), LTE4	Not reported	Not reported	No	No	Yes	Yes	Grants, European Community and the Polish Ministry of Science and Higher Education.
Sanak M, 2011	Eicosanoid profile	Not reported	Not reported	No	No	No	Yes	Not reported

Guideline for the diagnosis of NERD: methodological quality of included provocation tests studies (QUADAS-2)

Author, year	Type of test	Data collection	Patient recruitment method	Blinding	Adequate description of reference standard	Avoidance of differential bias	Avoidance of partial verification bias	Funding
Casadevall J, 2000	Intranasal	Not reported	Not reported	No*	No (referenced)	No	Yes	Grants
Nizankow-ska E, 2000	Oral & bronchial (inhalation)	Not reported	Not reported	No**	Yes	Yes	Yes	Not reported
Alonso-Llamazares A, 2002	Intranasal	Not reported	Not reported	No	No	No	Yes	Not reported
White A, 2006	Intranasal & oral	Other^	Not reported	No	Yes	Yes	No	Not reported
Barranco P, 2009	Bronchial (inhalation) & oral	Not reported	Not reported	No	Yes	No	No	Not reported
Celikel S, 2013	Intranasal & modified oral (with desensitisation)	Other^	Not reported	No	Yes	Yes	Yes	Not reported
Miller B, 2013	Intranasal	Not reported	Not reported	No	No	No	No	Not reported

*The index test was double-blinded; however, the diagnosis was already known before the index test based on clin. history or OPT.

**The OPT was single-blinded.

^Patients attended the clinic specifically for performance of OPT and desensitization.

Toelichting op de beoordeling met QUADAS-2

Partial verification bias (QUADAS-2 checklist item 5: Did all patients receive verification with reference test?)

Partial verification bias (also known as work-up bias, (primary) selection bias, or sequential ordering bias) occurs when not all of the study group receive confirmation of the diagnosis by the reference standard. If the results of the index test influence the decision to perform the reference standard then biased estimates of test performance may arise. If patients are randomly selected to receive the reference standard the overall diagnostic performance of the test is, in theory, unchanged. In most cases however, this selection is not random, possibly leading to biased estimates of the overall diagnostic accuracy.

Differential bias (QUADAS-2 checklist item 6: Was the same ref. standard used?)

Differential verification bias occurs when some of the index test results are verified by a different reference standard. This is especially a problem if these reference standards differ in their definition of the target condition, for example histopathology of the appendix and natural history for the detection of appendicitis. This usually occurs when patients testing positive on the index test receive a more accurate, often invasive, reference standard than those with a negative test result. The link (correlation) between a particular (negative) test result and being verified by a less accurate reference standard will affect measures of test accuracy in a similar way as for partial verification, but less seriously.

Reference

Whiting P, Rutjes AW, Reitsma JB, Bossuyt PM, Kleijnen J. The development of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in systematic reviews. BMC Med Res Methodol. 2003 Nov 10;3:25. PMID: 14606960.