ItchApp©: An App-based eDiary for Assessment of Chronic Pruritus in Clinical Trials

Abstract

Performing a reliable assessment of chronic pruritus 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, numerical rating scale, dynamic pruritus score) in order to validate the software application. Strong correlations were found for test-retest reliability (intraclass correlation coefficient: 0.865-0.977) and convergent validity (Spearman's r: 0.442-0.924). A feasibility questionnaire 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 evaluation of patients with chronic pruritus. It will be made available for future clinical trials.

Prurigo Activity Score (PAS): validity and reliability of a new instrument to monitor chronic prurigo

“…To test if it accurately covers the desired aspects of CPG, the PAS questionnaire was correlated with established instruments (convergent validity) . As there is no validated instrument to assess CPG lesions, we have chosen instruments assessing pruritus intensity (VAS, NRS) and quality of life (DLQI).…”

Validation of ‘ItchApp©’ in Poland and in the USA: multicentre validation study of an electronical diary for the assessment of pruritus

“…The results regarding the mean age, the gender distribution and the NRS mean score were quite similar in both countries (Table a, b). In the previous validation study for the German language, the NRS mean score was slightly lower, which could be due to the fact that the study also included patients with an NRS = 2, where this current study required NRS ≥3 . In Poland and the USA, the majority of the subjects had dermatological diseases (Table a, b), whereas the majority of the German subjects had multifactorial diseases .…”

“…(improved or worsened) (vii) Dynamic Score (DS): If improved, how much has the itching been reduced by? [Bands: 1–30% reduction (slight improvement); 31–50% reduction (moderate improvement); 51–70% reduction (good improvement); 71–100% reduction (very good improvement)] . After entering the patients’ password, the questionnaire data were automatically uploaded to the central database to ensure data quality and security.…”

“…ItchApp©s’ data were extracted from the providers (Arone) server into Microsoft Excel. The data were then transferred into a SPSS where the results of the paper‐based questionnaires were entered manually . The statistical analysis was carried out with IBM SPSS Statistics for Windows, version 25.0 (IBM Corp.).…”

“…A uniform instrument for recording subjects’ itch intensities is still missing . Validated measurement instruments allow for the assessment of the most important study outcomes like quality of life and pruritus intensity . The most frequently used validated instruments to assess pruritus intensity are the visual analog scale (VAS) and the numerical rating scale (NRS), and the ItchyQoL is used for measuring the impairment of quality of life in patients with CP .…”