Acta Dermato-Venereologica 99-7CompleteContent | Page 10

CLINICAL REPORT Validation of a Comprehensive Set of Pruritus Assessment Instruments: The Chronic Pruritus Tools Questionnaire PRURITOOLS Emely VERWEYEN 1 , Sonja STÄNDER 1 , Kiana KREITZ 2 , Inga HÖBEN 1 , Nani OSADA 1 , Marvin GERNART 1 , Claudia RIEPE 1 , Manuel PEREIRA 1 , Christine BLOME 3 , Matthias AUGUSTIN 3 and Claudia ZEIDLER 1 * Center for Chronic Pruritus, Department of Dermatology, University Hospital Münster, 2 Institute of Biostatistics and Clinical Research, University of Münster, Münster, 3 German Center for Health Services Research in Dermatology (CVderm), Institute for Health Services Research in Dermatology and Nursing (IVDP), University Medical Center Hamburg-Eppendorf, Hamburg, Germany 1 Few studies have validated standard measurement instruments for evaluation of chronic pruritus. The Chronic Pruritus Tools Questionnaire PRURITOOLS as- sembles a set of instruments for the assessment of pruritus, such as the visual analogue scale (horizontal 100-mm line), numerical rating scale (0–10), verbal rating scale, and information on pruritus quality and improvement during therapy. This study, with 40 sub- jects, analysed PRURITOOLS regarding convergent va- lidity and test–retest reliability (60 min), followed by a feasibility questionnaire. Test–retest reliability for PRURITOOLS items was excellent (intraclass correla- tion coefficient 0.84–1). Strong to very strong corre- lations between the pruritus intensity scales indicated convergent validity. The feasibility questionnaire sho- wed an overall acceptance of PRURITOOLS, and the majority of subjects (82.5%) considered it an appro- priate questionnaire to measure pruritus. In conclusi- on, PRURITOOLS offers validated tools for rapid pruri- tus assessment in routine care or endpoints of clinical trials. Key words: numerical rating scale; itch; prurigo; visual analo- gue scale; dynamic pruritus scale; worst pruritus. Accepted Mar 4, 2019; E-published Mar 5, 2019 Acta Derm Venereol 2019; 99: 657–663. 657 Corr: Claudia Zeidler, Center for Chronic Pruritus, Department of Der- matology, University Hospital Münster, Von-Esmarch-Str. 58, DE-48149 Münster, Germany. E-mail: [email protected] C hronic pruritus (CP) is, according to the International Forum for the Study of Itch (IFSI), defined as an it- ching sensation lasting over 6 weeks (1). This distressing symptom is associated with a variety of dermatological conditions and non-dermatological diseases, such as chronic renal insufficiency or liver diseases (2–5). Pru- ritus, described as the urge to scratch the skin to obtain relief, can have a high level of impact on quality of life (1, 6–8). New therapies are needed, since current treatments do not control pruritus in all patients and are often accompanied by side-effects (9–11). Collecting information on different aspects and attributes of pruritus is important for feedback on treatment efficiency and comparability of the assessed aspects across different studies. The problem of assessing CP in daily routine and clinical trials is that pruritus is a subjective multi- dimensional symptom, the presentation of which varies SIGNIFICANCE Itch lasting for longer than 6 weeks (chronic pruritus) is one of the main symptoms in dermatology and can appear not only in dermatological disorders, but also in systemic, neurological and psychological diseases. Chronic pruritus is often difficult to treat and has a high level of impact on a patient’s quality of life. There are only a few validated stan- dard measurement instruments available for the evaluation of chronic pruritus, which makes it difficult to assess this symptom objectively. This study validated the Chronic Pru- ritus Tools Questionnaire PRURITOOLS, which assembles a set of tools for the assessment of pruritus and can now be used in routine care or in clinical trials. from patient to patient. Finding a suitable, objective method of measurement is therefore challenging (12) and thus patient-reported outcomes (PRO) currently constitute the standard tools for assessment of pruritus. Validated and reliable PRO measurement tools evalua- ting CP in patients are required in order to collect and process information about CP both individually and collectively, especially in clinical trials. Not only for the assessment of chronic distress, but also for a more ac- tive involvement of patients in shared decision-making about treatment of their CP, simple and reliable tools measuring progress and outcome are required (13). Ho- wever, although pruritus is prevalent in 17% of the adult population (assessed in a large cohort of the working age population in Germany) (7), to date there are only a few validated standard measurement tools for the evaluation of pruritus. Unidimensional scales, such as the visual analogue scale (VAS), numerical rating scale (NRS) or verbal rating scale (VRS), have been validated in several languages (14, 15) and thus provide a method to obtain data to establish baselines for pruritus and accompany- ing symptoms in clinical trials (14). They show good reproducibility, are easily understood by the general population and have good psychometric properties (16). However, the qualities of sensory symptoms (pruritus, burning, stinging) assessed, recall periods and reference points (worst/mean pruritus) of the intensity scales used in different trials and in routine care vary largely and not all scales currently in use are validated. The aim of this study was to close the gap of pending validations and evaluate a set of tools that can be used in clinical This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3158 Acta Derm Venereol 2019; 99: 657–663