Acta Dermato-Venereologica issue 50:1 98-1CompleteContent | Page 39

142 SHORT COMMUNICATION Assessment of Quality of Life in Chronic Pruritus: Relationship Between ItchyQoL and Dermatological Life Quality Index in 1,150 Patients Astrid STUMPF 1 , Bettina PFLEIDERER 2 , Fleur FRITZ 3 , Nadi OSADA 4 , Suephy C. CHEN 5,6 and Sonja STÄNDER 4 Departments of 1 Psychosomatics and Psychotherapy, 4 Dermatology, Center for Chronic Pruritus, 2 Clinical Radiology, 3 Institute for Medical Informatics, University Hospital of Münster, Von-Esmarchstrasse 58, DE-48149 Münster, Germany, 5 Department of Dermatology, Emory University School of Medicine, Atlanta, and 6 Atlanta VA Medical Center, Decatur, GA, USA. E-mail: [email protected] Accepted Aug 29, 2017; Epub ahead of print Aug 30, 2017 Chronic pruritus (CP) (1) is a bothersome symptom of many diseases (2), and can profoundly reduce quality of life (QoL) (3, 4). In order to evaluate the impact of reduction in QoL in patients with CP independently of their underlying disease, the ItchyQoL questionnaire was developed in 2008 by Desai et al. (5) and translated into German by Krause et al. (6) in 2013 (GerItchyQoL). ItchyQoL is a 22-item questionnaire containing 3 domains: symptoms, functions and emotions. The Dermatological Life Quality Index (DLQI) (7) is currently often used in dermatological patients in general (8), but also in patients with CP (9). ItchyQoL has been developed and validated for all types of CP, while DLQI appears to be valid only in conditions with visible lesions, such as dermatoses or excoriations. Despite the fact that many studies have used DLQI in CP and several studies have used ItchyQoL, the 2 instruments have never been compared. We hypothesized that ItchyQoL (in its German version) more specifically detects symptoms in patients with CP, while the detection of function and emotion might be more similar to DLQI. To examine this hypothesis, we analysed the responses of a large cohort of patients in whom both questionnaires have been applied. MATERIALS AND METHODS A data sample of 2,360 ItchyQoL and 2,343 DLQI scores that were completed by 1,150 patients with CP were examined. The patients (mean age 58.9  ±  17.1 years, 511 (44.4%) males) completed both questionnaires on the same day on a tablet computer or with a paper and pencil version. The questionnaires were used during daily routine; therefore the patients completed the questionnaires several times. A total of 1,150 ItchyQoL questionnaires and 1,142 DLQI questionnaires were completed during the first visit, 635 ItchyQoL questionnaires and 631 DLQI questionnaires during the second visit, 347 ItchyQoL questionnaires and 343 DLQI questionnaires during the 3 rd visit, 145 ItchyQoL questionnaires and DLQI each during the 4 th visit, and 45 ItchyQoL question- naires and DLQI each during the 5 th visit. A total of 38 ItchyQoL and 37 DLQI questionnaires were completed during the 6 th visit. Furthermore, patients were asked about their mean itch intensity during the past 24 h (“current”) and during the past 4 weeks (“4 weeks”) on a visual analogue scale (VAS). DLQI (7) consists of 10 items, each with a score of 0–3 points (total score range 0–30 points) for a recall period of 7 days. ItchyQoL contains 22 items with a score of 1–5 points also for the past 7 days. The total score of ItchyQoL and GerItchyQoL used in this study is calculated as the mean scores of the patient’s responses to all 22 items. Questions were classified according to 3 dimensions: symptom, function and emotion (6). Scores range from 1 to 5. To compare single “identical” items between the 2 doi: 10.2340/00015555-2782 Acta Derm Venereol 2018; 98: 142–143 questionnaires, those with the same objectives were matched (see Table SI 1 ). For the statistical tests the total of the 2,360 ItchyQoL and 2,343 DLQI scores were used. Internal consistency of the tests was as- sessed by calculating the Cronbach’s α coefficient for each domain of the GerItchyQol (6), the mean total score of the GerItchyQol and the mean total score of the DLQI. Values between 0.8 and 0.9 reflect excellent internal consistency, values > 0.9 are related to excessive consistency, pointing hereby to item redundancy (6). Pearson’s correlation analyses between the total scores of both instruments were performed, as well as non-parametric Spearman rho correlations for comparis on of single items. Furthermore, the VAS were divided into 4 bands (1: VAS 0 to < 3; 2: VAS ≥ 3 to < 7; 3: VAS ≥ 7 to < 9; 4: ≥ 9) (10). Non-parametric Kruskal–Wal- lis tests for independent samples were used to examine the dif- ferences between ItchyQoL and DLQI scores in each of these 4 bands. Statistical analyses were performed with SPSS (IPM SPSS Statistics Version 24). RESULTS The mean total scores of the DLQI and the ItchyQol presented a high internal consistency with a Cronbach’s α coefficient of 0.884 and 0.940, respectively. Similarly, the ItchyQol dimensions emotion, symptom and function depicted a high internal consistency with a Cronbach’s α coefficient of 0.893, 0.814 and 0.893, respectively. Pearson’s correlation analysis revealed a strong correla- tion between the total scores of the DLQI and the ItchyQoL (r = 0.745, p < 0.0001; Fig. S1 1 ). Correlation analysis of the scores of a subset of single items showed significant moderate to strong correlations, as shown in Table SI 1 . Furthermore, the overall DLQI score correlated mode- rately, but significantly, with the 3 subscores of ItchyQoL (ItchyQoL score emotion 0.709, p < 0.001, ItchyQoL score function 0.766, p < 0.001 and ItchyQoL score symptom 0.591, p < 0.001). We found significantly increasing ItchyQoL and DLQI scores in association with the 4 VAS bands for all 4 sub- tests (Fig. S2 1 ). The pairwise comparisons of all 4 bands were significant (p ≤ 0.0001). No significant differences were found between the scores for the 1 st and 5 th visits. DISCUSSION The DLQI questionnaire, assessing reduction in QoL due to skin diseases, and the ItchyQoL, a pruritus-specific QoL https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2782 1 This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica.