Summary of included studies
The systematic search identified 1,494 unique records. 149 studies
[31-180] were included after application of our predefined
eligibility criteria. Figure 1 llustrates the PRISmeta-analyses
flowchart for the study screening and selection process. This resulted
in 24,489 subjects included in the analysis. The current SR includes
representative data for thirty-two countries and all continents. The
data principally originate from Europe (54.3%), Asia (19.9%) and
America (13.9%). Only 13.4% of eligible data are derived from
multicentre studies.
The studies evaluated were predominantly prospective (63.8%) including
consecutive (51.0%) and randomized (6.7%) studies. Within the
retrospective studies (34.2%), most were performed consecutively
(30.2%). The studies included are mostly cross-sectional (59.1%) or
cohort studies (35.6%). Only 5.4% are case controls. Most studies
include subjects under 18 years of age (79.2%), most of which were in
infants or children ≤12 years of age (60.4%). Studies exclusive on
adults represent only 7.4%. The included studies where largely
performed in an allergy or paediatric clinic setting (94.6%). All
included studies used OFC as a reference standard in a proportion of
patients, most of them in over 70% of the subjects included. Only 7.4%
of studies explicitly stated OFCs were done in all subjects. Overall,
63.8% used open OFCs and 21.5% double blind placebo-controlled food
challenges (DBPCFC). The full summary of characteristics of the included
studies is given in Table 1 . Further information for individual
studies is compiled in Table S1 .
Nineteen different index tests were identified, most commonly sIgE (128
studies), component resolved diagnosis (CRD) (87 studies) and SPT (79
studies). Additional identified tests were SPP (15 studies), basophil
activation test (BAT) (13 studies), mast cell activation test
(meta-analysesT) (2 studies) [38, 149] and bead-based epitope assay
(BBEA) [159]. Table S2 lists the identified index test
studies. Note that studies may have more than one diagnostic test
reported. Evaluable data was available for 21 foods: foremost peanut
(34.2%) followed by HE (25.5%), CM (18.1%), tree nuts (12.1%), wheat
(10.7%), sesame (6.0%), soy and shellfish (4.7%). All foods tested in
the studies are listed in Tables S3 . The group of most
frequently studied foods with three or more included publications per
index test were peanut, CM, baked HE, extensively heated HE, raw HE,
sesame, soy, walnut, hazelnut, cashew, almond, wheat, and shrimp.Table 2 summarizes results for each food where meta-analyses
was possible.