Acta Dermato-Venereologica Issue No. 97-5 97-5CompleteContent | Page 13

INVESTIGATIVE REPORT ItchApp©: An App-based eDiary for Assessment of Chronic Pruritus in Clinical Trials Marvin GERNART 1 , Athanasios TSIANAKAS 1 , Claudia ZEIDLER 1 , Claudia RIEPE 1 , Nani OSADA 1 , David PIHAN 2 and Sonja STÄNDER 1 Center for Chronic Pruritus, Department of Dermatology, University Hospital Münster, Germany, and 2 Arone, Saint-Maur des Fosses, France 1 Performing a reliable assessment of chronic pruri- tus remains a challenge. Electronic diaries are often used, but many of the scales have not been validated. ItchApp © was developed for Android smartphones in order to address this lack. A total of 40 subjects with chronic pruritus completed questionnaires both on paper and with ItchApp © (verbal rating scale, nume- rical rating scale, dynamic pruritus score) in order to validate the software application. Strong correlations were found for test–retest reliability (intraclass cor- relation coefficient: 0.865–0.977) and convergent va- lidity (Spearman’s r: 0.442–0.924). A feasibility ques- tionnaire for ItchApp © revealed a high level of user friendliness and compliance. This was confirmed in a randomized controlled trial with 68 subjects, for which the clinically important difference in the numerical rating scale values for ItchApp © was calculated (2.61 points). In summary, ItchApp © is a recently developed eDiary that can provide experts with a reliable evalua- tion of patients with chronic pruritus. It will be made available for future clinical trials. Key words: itch; visual analogue scale; numerical rating scale; minimal clinically important difference; psychometric. Accepted Dec 15, 2016; Epub ahead of print Dec 16, 2016 Acta Derm Venereol 2017; 97: 601–606. 601 Corr: Sonja Ständer, Center of Chronic Pruritus, Department of Derma- tology, University of Münster, Von-Esmarch-Str. 58, DE-48149 Münster, Germany. E-mail: [email protected] C hronic pruritus (CP) is a frequent symptom with a high impact on patients’ quality of life (1–3). To date, there is almost no specific therapy available that successfully alleviates itching (4). New therapies are thus urgently needed. Many novel mechanisms of pruritus have been identified recently, allowing experts to establish therapy targets. Although many randomized controlled trials (RCT) have been initiated (5), it is dif- ficult to assess pruritus because it is a subjective symptom (6). The study end-points, usually the determination of the course of the itch and quality of life, can be assessed by validated patient-rep orted outcomes (PRO). Several PRO questionnaires have been developed to better assist in evaluating CP in recent years, including the visual analogue scale (VAS), numerical rating scale (NRS) (7, 8), ItchyQoL (9), 5-D Itch Scale (10) and the pruritus- specific patient benefit index (11). The most common way to assess the course of pruritus is the NRS and VAS, which serve in many RCTs as the primary endpoint (6). In such assessment using paper-based diaries, certain criteria cannot be regulated and properly documented, including the exact time at which a subject completed cer- tain questions or the entirety of the questionnaire. Such hindrances have often proven to be great disadvantages in RCTs. A further issue is the quality of data in paper-based questionnaires. Subjects may forget to use a physical diary and attempt to complete it quickly prior to their follow-up visit. As a consequence, this retrospective data may not be entirely reliable, and the prospective course of the pruritus is thus difficult to estimate accurately. In order to address these issues, electronic diaries (eDiaries) have been adapted for use in RCTs. Several providers (e.g. PHT Corporation, Boston, USA; ERT, Philadel- phia, USA) offer eDiaries with endpoints identified by sponsors. There are, however, various issues attributed to the use of eDiaries. The devices provided to subjects are often bulky and the questions may be non-validated or have been assessed with non-validated methods. In order to address these issues we designed a novel software application (app) for use in clinical trials that is easy to use on Android smartphones (Appendix S1 1 ). The app contains multiple questions validated by experts (members of the Special Interest Group ”Scoring Itch in Clinical Trials” of the IFSI) regarding the course of patients’ itch, which is intended for use on a daily basis. ItchApp © was developed in compliance with validation guidelines and security regulations (e.g. audit trails, electronic signatures, data encryption, etc.). A specific feature restricts subjects’ ability to answer questions re- trospectively, thus ensuring the quality of the data entered. This assures subjects, physicians and researchers of ac- curate information. The aim of this study was to validate ItchApp © as a novel instrument. METHODS Validation study Subjects (≥ 18 years old) with CP with a score of at least 2 points on the NRS were asked to use ItchApp © twice within 1 h (Fig. S1 1 ). This time period was selected according to a previous study (7) and the notion that it is acceptable in terms of a balance be­ tween the natural daily variabilities in itch, the minimized recall bias due to the number of questions, and distraction due to the https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2602 1 This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2017 Acta Dermato-Venereologica. doi: 10.2340/00015555-2602 Acta Derm Venereol 2017; 97: 601–606