The accuracy of patient-reported measures for GI symptoms: a comparison of real time and retrospective reports

Obtaining accurate information about gastrointestinal (GI) symptoms is critical to achieving the goals of clinical research and practice. The accuracy of patient data is especially important for functional GI disorders (e.g., IBS) whose symptoms lack a biomarker and index illness severity and treatment response. Retrospective patient-reported data are vulnerable to forgetting and various cognitive biases whose impact has not been systematically studied in patients with GI disorders. The aim of this study was to document the accuracy of patient-reported GI symptoms over a reporting period (1 week) most representative of the time frame used in research and clinical care.

Subjects were 273 Rome III-diagnosed IBS patients (mean age = 39 years, 89% F) who completed end of day GI symptom ratings for 7 days using an electronic diary. On Day 8, Subjects recalled the frequency and/or intensity of IBS symptoms over the past 7 days. Reports were then compared against a validation criterion based on aggregated end of day ratings.

At the group level, subjects recalled most accurately abdominal pain and urgency intensity at their worst, urgency days, and stool frequency. When data were analyzed at the individual level, a subgroup of subjects had difficulty recalling accurately symptoms that showed convergence between recall and real time reports at the group level.

Although many patients' recollection for specific GI symptoms (e.g., worst pain, stool frequency) is reasonably accurate, a non-trivial number of other symptoms (e.g., typical pain) are vulnerable to distortion from recall biases that can reduce sensitivity of detecting treatment effects in clinical and research settings.