Refinement and validation of the ItchyQoL using classical test theory and item response theory resulted in a reduction of the response categories from a 5-point to a 3-point scale.

BACKGROUND: The ItchyQoL is an itch-specific patient-reported outcome measure used to assess quality of life in patients with chronic pruritus (CP). OBJECTIVES: We aimed to assess and extend the psychometric properties of the ItchyQoL using classical test theory (CTT) and item response theory (IRT). METHODS: Item characteristic curves were analysed to investigate whether the response categories were functioning optimally. Confirmatory factor analyses were carried out on the ItchyQoL prior to and after rescoring of the response categories. We conducted a Rasch analysis for the ItchyQoL with revised response options and assessed the mean fit residuals in addition to the assumptions of unidimensionality and local independence. RESULTS: In total, 551 patients with CP from nine European countries completed the 22 items of the ItchyQoL. IRT analysis supported the revision of response options from five points to three. This revision was supported by excellent structural validity using CTT. The overall fit to the Rasch model was adequate. Unidimensionality was supported by the ItchyQoL overall scale and by the single subscales; however, local independence was violated in eight cases. CONCLUSIONS: We suggest a revision of the response categories of the ItchyQoL from a 5-point to a 3-point scale. When this revision was applied, the ItchyQoL showed excellent structural validity according to CTT and IRT/Rasch. The calculation of an overall ItchyQoL sum score is allowed.

Recommended core outcome instruments for health-related quality of life, long-term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting.

BACKGROUND: The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema (AE) clinical trials. Previous consensus meetings have agreed on preferred instruments for clinician-reported signs (Eczema Area and Severity Index, EASI) and patient-reported symptoms (Patient-Oriented Eczema Measure, POEM). This paper reports consensus decisions from the HOME VII meeting. OBJECTIVES: To complete the core outcome set for AE by agreeing on core outcome instruments for the domains of quality of life (QoL), long-term control and itch intensity. METHODS: A face-to-face consensus meeting was held in Tokyo, Japan (8-10 April 2019) including 75 participants (49 healthcare professionals/methodologists, 14 patients, 12 industry representatives) from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using predefined consensus rules. RESULTS: It was agreed by consensus that QoL should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children's Dermatology Life Quality Index (CDLQI) for children and the Infant's Dermatology Quality of Life Index (IDQoL) for infants. For long-term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long-term control. The peak itch numerical rating scale (NRS)-11 past 24 h was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum. CONCLUSIONS: For now, the core outcome set for clinical trials in AE is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments.

IDQoL, CDLQI and the 45-item CADIS received a sufficient content validity rating during the HOME VII meeting in Japan: a group discussion study.

BACKGROUND: The Harmonising Outcome Measures for Eczema (HOME) initiative has agreed that quality of life should be measured in all atopic eczema clinical trials. Various candidate instruments exist for this domain but their content validity in atopic eczema is largely unclear. OBJECTIVE: To assess the content validity of quality-of-life candidate instruments for atopic eczema in infants, children and adults in order to aid the decision on what instrument to include in the core outcome set for the quality-of-life domain. METHODS: Six group discussions were conducted at the HOME VII Meeting in Tokyo. Each group was composed of 8-12 patients or parents of patients, clinicians, methodologists and pharmaceutical industry delegates and discussed one or two candidate instruments. The COSMIN criteria on relevance, comprehensiveness and comprehensibility were used to determine the overall content validity rating per instrument. RESULTS: Content validity of the Infant's Dermatitis Quality of Life Index, Children's Dermatology Life Quality Index and the Childhood Atopic Dermatitis Impact Scale (CADIS) long-form was rated as sufficient (+). Results for the CADIS short-form, DLQI and Skindex were inconsistent (±). DISABKIDS, Infants and Toddlers Dermatology Quality of Life and ABS-A were classified as having insufficient content validity. CONCLUSIONS: The content validity rating allowed for a comparison of all candidate instruments and informed the consensus-seeking process regarding the core instrument for the quality-of-life domain.

Hyperhidrosis Quality of Life Index (HidroQoL©): further validation and clinical application in patients with axillary hyperhidrosis using data from a phase III randomized controlled trial.

BACKGROUND: The Hyperhidrosis Quality of Life Index (HidroQoL©) is a validated patient-reported outcome measure capturing the quality of life of people affected by hyperhidrosis. OBJECTIVES: We aimed to extend the validity evidence to physician-confirmed diagnosis of primary axillary hyperhidrosis. METHODS: Data from a phase III randomized placebo-controlled clinical trial were used (n = 171). Confirmatory factor analysis was carried out to confirm the a priori two-factor structure of the HidroQoL. Internal consistency was assessed using Cronbach's α. Intraclass correlation coefficients (ICCs) were calculated to evaluate test-retest reliability after days -7 to -4. Convergent validity was assessed using correlations with the Dermatology Life Quality Index (DLQI), the Hyperhidrosis Disease Severity Scale (HDSS) and gravimetric sweat production. Known groups were analysed to evaluate discriminative validity. Responsiveness after 29 days was assessed and minimal important difference (MID) values were calculated using both anchor- and distribution-based approaches. All analyses were carried out for total HidroQoL and its two domains. RESULTS: The two-factor structure of the HidroQoL was confirmed. Internal consistency and test-retest reliability were strong (Cronbach's α 0·81-0·90; ICCs 0·89-0·93). Correlations with other outcome measures were in line with a priori hypotheses. The HidroQoL discriminated between different severity groups (P ≤ 0·001) and showed sensitivity to change towards improvement (P < 0·001). An MID value of 4 is proposed for the total scale. CONCLUSIONS: This study supports excellent measurement properties including clinical applicability of the HidroQoL in primary axillary hyperhidrosis and suggests a MID of 4 be applied to clinical trial data.

Recommended core outcome instruments for health-related quality of life, long-term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting.

BACKGROUND: The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema clinical trials. Previous consensus meetings have agreed upon preferred instruments for clinician-reported signs (Eczema Area and Severity Index - EASI) and patient-reported symptoms (Patient-Oriented Eczema Measure - POEM). This paper reports consensus decisions from the HOME VII meeting. OBJECTIVE: To complete the core outcome set for atopic eczema by agreeing upon core outcome instruments for the domains of quality of life, long-term control and itch intensity. METHODS: Face-to-face consensus meeting held in Tokyo, Japan (8th to 10th April, 2019) including 74 participants (47 healthcare professionals/methodologists, 14 patients, 13 industry representatives), from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using pre-defined consensus rules. RESULTS: It was agreed by consensus that quality of life should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children's Dermatology Life Quality Index (CDLQI) for children, and the Infant's Dermatology Quality of Life Index (IDQoL) for infants. For long-term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long-term control. The peak itch numerical rating scale(NRS)-11 past 24 hours was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum. CONCLUSIONS: For now, the core outcome set for clinical trials in atopic eczema is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments.

Development of a validated short-form of the Childhood Atopic Dermatitis Impact Scale, the CADIS-SF15.

BACKGROUND: The Childhood Atopic Dermatitis Impact Scale (CADIS) with 45 items may be burdensome to complete. We therefore aimed to develop a CADIS short-form. METHODS: Parents of 300 children completed the prototype CADIS. Exploratory factor analysis was conducted on the 45-item CADIS version. The most representative items were chosen. Confirmatory factor analysis was used to confirm the a priori factor structure. Content validity was assessed in a focus group of patients, parents, clinicians, methodologists and industry delegates. Internal consistency, 48-h test-retest reliability, construct validity and responsiveness of the newly developed short-form were assessed. RESULTS: A total of 270 families provided data at baseline, 34 after 48 h and 228 after 4 weeks. Fourteen items of three different factors fulfilled the proposed eligibility criteria and were included in the draft short-form. After the content validity rating, one item relating to the child's sleep was added to further improve content validity. The confirmatory factor analyses showed good model fit, and a 15-item short-form was initiated, the CADIS-SF15. The total scale and the three domains showed good internal consistency and test-retest reliability. The correlation between SCORAD and other subjective measures was consistent with our hypotheses. Differences in scores between mild, moderate and severe AD patients were significant, and the CADIS-SF15 was able to detect changes in 'improving' patients over time. CONCLUSION: The CADIS-SF15 with 15 items in three domains is an internally consistent, reliable, valid, responsive and brief measure of QoL in children affected with AD and their parents. Further evaluation of clinical applicability is required.

Evaluation of responsiveness and estimation of smallest detectable change and minimal important change scores for the Childhood Atopic Dermatitis Impact Scale.

BACKGROUND: The Childhood Atopic Dermatitis Impact Scale (CADIS) is an instrument to measure quality of life in young children affected by atopic dermatitis, and their parents. OBJECTIVES: To evaluate the responsiveness (sensitivity to change), smallest detectable change (SDC) and minimal important change (MIC) of the CADIS. METHODS: Parents and primary caregivers of 300 young children completed the CADIS and a global rating of their child's skin condition at baseline and a 4-week follow-up. Kruskal-Wallis tests, Wilcoxon tests and effect sizes were used to assess responsiveness. The SDC can be seen as a change beyond measurement error. Anchor-based and distribution-based methods, and an integration of both methods were used to estimate the MIC. RESULTS: In total, 270 families provided data at baseline and 228 at follow-up. The CADIS total change score and most of the domain scores had moderate-to-strong correlations with the skin change score. Patients were grouped according to the skin change score, which served as an anchor. Children whose parents noted an improvement of the skin showed lower CADIS scores at follow-up (P < 0·001). For the SDC we obtained score changes of 1·34 points on the total score and < 1·0 points on each domain score. All detected MIC values passed the SDC cut-off. CONCLUSIONS: The CADIS is sensitive to change towards improvement of quality of life. A change > 12% on the total score or each domain score very likely represents a clinically important change. What's already known about this topic? Atopic dermatitis reduces the quality of life of affected children and their parents. The Childhood Atopic Dermatitis Impact Scale (CADIS) has been evaluated and translated into two further languages. What does this study add? Further validation of the responsiveness of the CADIS, and whether it is sensitive to change in patients whose condition had changed. Calculation of the smallest detectable change. What are the clinical implications of this work? Estimation of the minimal important change in CADIS provides benchmarks for clinical practice.