Development and preliminary validation of the Adolescent Psoriasis Quality of Life instrument: a disease-specific measure of quality of life in adolescents with psoriasis.

BACKGROUND: No age-appropriate and disease-specific instrument currently exists to measure health-related quality of life in adolescents with psoriasis (patients aged 12-17 years). OBJECTIVES: To develop and provide preliminary validation of the Adolescent Psoriasis Quality of Life instrument. METHODS: Qualitative interviews with adolescents with psoriasis, parents of adolescents with psoriasis, and healthcare professionals informed the development of an initial item pool for the instrument, which was subsequently refined through cognitive interviews. Finally, data from an independent sample of adolescents with psoriasis (n = 50) were used for item reduction, scale construction and initial validation, using a combination of techniques from classical test theory and Rasch modelling. RESULTS: Rich qualitative data concerning health-related quality of life in adolescents with psoriasis (from 18 adolescents, 14 parents and four healthcare professionals), combined with cognitive interview testing (n = 12), resulted in a 41-item draft version. Item reduction led to the final version, a 17-item instrument consisting of two subscales showing good fit to their respective Rasch models: psychosocial impact (12 items) and the impact of physical symptoms and treatment (five items). All a priori stated hypotheses regarding construct validity were supported. Both subscales and the total scale showed acceptable test-retest reliabilities (intraclass correlations 0·97, 0·89 and 0·96) and internal consistencies (Cronbach's α 0·94, 0·81 and 0·95). CONCLUSIONS: The preliminary form of the Adolescent Psoriasis Quality of Life instrument shows promising psychometric properties. It can be used in daily clinical practice and research to support a patient-centred approach and inform treatment planning. What's already known about this topic? Health-related quality of life (HRQoL) instruments should be targeted towards narrowly defined age groups, as life contexts of children, adolescents and adults may differ substantially. Dermatology-specific instruments have been used to measure HRQoL in adolescents with psoriasis, but it is not known whether these instruments accurately capture all relevant HRQoL aspects in adolescent psoriasis. Age-appropriate and psoriasis-specific instruments may be more sensitive for HRQoL issues experienced by this unique group. What does this study add? The Adolescent Psoriasis Quality of Life instrument represents the first age-appropriate and disease-specific instrument for measuring HRQoL in adolescents (12-17 years old) with psoriasis. It is intended for use in daily clinical practice to support dermatologists and other healthcare professionals in providing optimal care for adolescents with psoriasis.

ViPAR: a software platform for the Virtual Pooling and Analysis of Research Data.

BACKGROUND: Research studies exploring the determinants of disease require sufficient statistical power to detect meaningful effects. Sample size is often increased through centralized pooling of disparately located datasets, though ethical, privacy and data ownership issues can often hamper this process. Methods that facilitate the sharing of research data that are sympathetic with these issues and which allow flexible and detailed statistical analyses are therefore in critical need. We have created a software platform for the Virtual Pooling and Analysis of Research data (ViPAR), which employs free and open source methods to provide researchers with a web-based platform to analyse datasets housed in disparate locations. METHODS: Database federation permits controlled access to remotely located datasets from a central location. The Secure Shell protocol allows data to be securely exchanged between devices over an insecure network. ViPAR combines these free technologies into a solution that facilitates 'virtual pooling' where data can be temporarily pooled into computer memory and made available for analysis without the need for permanent central storage. RESULTS: Within the ViPAR infrastructure, remote sites manage their own harmonized research dataset in a database hosted at their site, while a central server hosts the data federation component and a secure analysis portal. When an analysis is initiated, requested data are retrieved from each remote site and virtually pooled at the central site. The data are then analysed by statistical software and, on completion, results of the analysis are returned to the user and the virtually pooled data are removed from memory. CONCLUSIONS: ViPAR is a secure, flexible and powerful analysis platform built on open source technology that is currently in use by large international consortia, and is made publicly available at [http://bioinformatics.childhealthresearch.org.au/software/vipar/].

Wood smoke in a controlled exposure experiment with human volunteers.

Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung function and normal bronchial reactivity were randomly exposed for 3 h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m³ (low) and 400 µg/m³ (high) under controlled environmental conditions. The range for PM2.5 load observed for single experiments was 165-303 µg/m³ for the low exposure and 205-662 µg/m³ for the high exposure, whereas particle loads during clean air exposure most often were below the detection limit (< 20 µg/m³). Health effects were evaluated in relation to rated changes in symptoms and environmental perception using a computerized questionnaire and a potentiometer. Subjective symptoms were generally weak, but when combining the effect of each of the symptoms into categorical symptom indices, significant effects were found for "environmental perception" (p = 0.0007), "irritative body perceptions" (p = 0.0127), "psychological/neurological effects" (p = 0.0075) and "weak inflammatory responses" (p = 0.0003). Furthermore, significant effects (p = 0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating and caused irritated mucosas in humans. The knowledge gained in this study on subjective-rated symptoms may be important for understanding human response to wood-smoke exposure.