Comparison with previous research
The previous SR on diagnostic test accuracy [8] included only studies where at least 50% of subjects had a DBPCFC as reference standard. While this approach may potentially increase the rigor of the studies included, it may also exclude evidence from various geographical regions and clinical settings where the logistics of a DBPCFC are not feasible or practical and may exclude a subset of patients seen in allergy clinic who do not have an indication or do not accept to undergo an OFC (e.g. highly sensitized subjects or patients with a recent history of reaction to the culprit food). As the objective of the current systematic review is to inform clinical recommendations, we chose to include index tests validated with other OFC techniques, namely open OFCs which are widely used in clinical practice and reliable in most clinical cases. We considered merging the studies included in the previous SR in this SR as an update and a way to increase the number of studies; however, we decided not to include older studies as methodologies have changed and available diagnostic tools have higher quality and diversity compared to those used prior to 2012.