Zsa Zsa Weerts

Smart Data Collection for the Assessment of Treatment Effects in IBS 213 9 Introduction Irritable Bowel Syndrome (IBS) is a highly prevalent chronic disorder of brain-gut- interaction characterized by recurrent abdominal pain and altered bowel habits. 1 Since well-defined organic causes and validated biomarkers for IBS are lacking, patient reported outcome measures (PROMs) are crucial to assess treatment response. In accordance, drug regulatory authorities currently recommend using end-of-day symptom scores in IBS trials to measure drug efficacy. 2,3 Diaries are generally considered suitable to measure these end-of-day gastro-intestinal (GI) symptom scores and have the ability to capture symptom variability over time. 4 The validity and reliability of paper diaries, however, may be impeded by fake adherence 5 , i.e. falsifying or backfilling written answers outside of the proposed time-window to forge good adherence. 6 The gap between reported and actual adherence to paper diaries has shown to be as large as 80% in some studies. 7 Because backfilling introduces considerable recall and ecological bias 8 , using paper diaries can distort trial results, which can ultimately lead to incorrect conclusions about treatments. Efficacy endpoints in clinical trials should therefore, preferably not be assessed by paper diaries. Recent technological advancements and the widespread availability of smartphones have given rise to numerous health-related applications and electronic diaries in the last decade 9-12 , both in clinical and research settings. A digitalized data-collection provides several advantages over a paper-based data-collection as it results in higher data entry quality and more efficient data handling. 13 For example, responses can be verified automatically by built-in response requirements, routing, and data validation, and manual data transcription can be omitted. More importantly, data entry of previous days can be prevented and all entries can be given a date- and time-stamp, generating more valid (momentary) results and allowing assessment of actual adherence to the diary. Studies in (non-IBS) patients that have implemented electronic diaries have reported excellent adherence, ranging from 76%-100%. 5,14,15 These advantages encouraged our group to implement a digital data-collection framework and develop a smartphone application that can be used as a digital symptom diary. This diary was used to collect Food and Drug Administration (FDA) recommended efficacy outcomes in our randomized placebo-controlled clinical trial (RCT) on the efficacy of peppermint oil in IBS, the PERSUADE study. 16 The current study describes the development and evaluates the performance of the overall digital framework used for data-collection in that clinical trial. Within the realms of IBS trials, the use of a digital symptom diary is relatively new; most previous studies did not report