Abstract
BACKGROUND: Existing tools for nail psoriasis are complex and may not adequately measure outcomes that are important to patients.
OBJECTIVES: We have developed and validated a new tool, the Nail Assessment in Psoriasis and Psoriatic Arthritis (NAPPA), with three components: a questionnaire assessing quality of life (NAPPA-QoL), a two-part questionnaire assessing patient-relevant treatment benefits (the Patient Benefit Index, NAPPA-PBI) and a psoriasis Clinical Assessment of Severity (NAPPA-CLIN).
METHODS: Development of the questionnaires involved multiple steps: (i) collection of items about nail psoriasis-related impairments and treatment goals; (ii) selection of 48 items by an expert panel, including patients; (iii) translation into eight languages; (iv) feasibility testing and (v) longitudinal validation in six countries.
RESULTS: Patients found the questionnaires clear (84%) and comprehensible (95%). NAPPA-QoL and NAPPA-PBI scores correlated moderately with clinical outcomes [e.g. Nail Psoriasis Severity Index (NAPSI)] and markedly with other quality-of-life questionnaires (e.g. EQ-5D™). Both questionnaires were sensitive to change. Internal consistency was good (Cronbach α ≥ 0.88 for all scales). The NAPPA-CLIN, a brief version of NAPSI that involves assessment of only four digits rather than all 20, was found to correlate highly with total NAPSI score (r = 0.97, P < 0.001).
CONCLUSIONS: Overall, the three-component NAPPA tool is a valid, reliable and practical instrument to assess patient-relevant nail psoriasis outcomes.
Originalsprog | Engelsk |
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Tidsskrift | British Journal of Dermatology |
Vol/bind | 170 |
Udgave nummer | 3 |
Sider (fra-til) | 591-8 |
Antal sider | 8 |
ISSN | 0007-0963 |
DOI | |
Status | Udgivet - mar. 2014 |