Interpretation of subjective symptoms in double-blind placebo-controlled food challenges -: interobserver reliability

Background: Subjective symptoms after food challenges are difficult to interpret and no standard is available. We discuss a strategy for how to interpret a diary. Furthermore, the interobserver reliability is evaluated. Methods: Diaries for 32 patients with subjective symptoms were used. The diaries were re-evaluated with a predefined strategy by three independent observers. Results: The proportion of positives was 21.9% among the old diagnoses, according to the new approach 34.4% (observers I and II) and 37.5% (observer III) were positive. The new approach had high interobserver reliability (97 and 100%). Conclusions: The proportion of positives depends on how subjective symptoms are interpreted. Interpretations of subjective symptoms in diaries could be made with high interobserver reliability.