The validity of a symptom diary in ratings of dyspepsia measured against a detailed interview: Do patients and clinicians agree in their assessment of symptoms?

Background: Patients' self-assessment of symptoms is central in drug treatment trials of functional dyspepsia. The validity of such ratings is important. Aim: To validate a diary for monitoring severity and duration of dyspepsia. Method: We compared the diary-cards with two clinicians' ratings of the patient's open-ended responses to the same questions administered by interview. Agreements were evaluated by estimation of the overall agreement and weighted kappa values (Kw). Results: Forty-six patients were evaluated. The Kw between the two clinicians rating severity and duration of symptoms were 0.59 and 0.86, respectively. Overall agreement between patients' diary rating and clinicians' consensus rating of severity were 52%, and a moderate agreement with Kw of 0.49 was found. For duration of symptoms the overall agreement and Kw were 67% and 0.59, respectively. Qualitative data revealed useful insight in the possible causes of suboptimal agreement between patients and clinicians. Conclusions: We found a moderate to good agreement between patient and observer ratings, indicating that patients to a reasonable extent interpret severity and duration of dyspeptic symptoms in the same way as do investigators. A ceiling effect of the duration scale indicates suboptimal response categories, which should be adjusted before further use.