The suitability of quality-of-life questionnaires for psoriasis research - A systematic literature review

Objective: To critically appraise the suitability of current quality-of-life (QOL) questionnaires for psoriasis research. Data Sources: Computerized searches of 5 bibliographic databases. Questionnaire Selection: Predefined criteria were used to identify QOL questionnaires in dermatologic studies. Two investigators independently assessed and agreed on multidimensional generic, dermatology-specific, and psoriasis-specific QOL questionnaires for inclusion. Data Extraction: Data were extracted on the internal structure, reliability, and validity of the included questionnaires. Data Synthesis: Three generic, 3 dermatology-specific, and none of the psoriasis-specific questionnaires met the inclusion criteria: the Nottingham Health Profile (NHP), the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), the Sickness Impact Profile (SIP), the Dermatology Quality of Life Scales (DQOLS), the Dermatology-Specific Quality of Life Instrument (DSQL), and the Skindex-29. The generic NHP, SF-36 and SIP are well established, reliable, and valid. Although the data are not conclusive, the SF-36 was useful to assess effects of psoriasis on its component scales. The dermatology-specific DQOLS, DSQL, and Skindex-29 are relatively new and, therefore, less widely tested. Available psychometric data demonstrated the reliability and validity, of all 3 dermatology-specific questionnaires. The Skindex-29 was also useful to assess change. Conclusions: None of the identified psoriasis-specific questionnaires met the inclusion criteria. Data on. the suitability of the included questionnaires for psoriasis research were relatively sparse. The included generic questionnaires allow comparisons with nondermatologic diseases but do not allow assessment of relevant dermatology-specific aspects and are not sensitive to subtle effects of psoriasis on QOL. On the basis of the psychometric data of the present review, we find the Skindex-29 to be the most valuable dermatology-specific questionnaire for psoriasis research. Combination of the Skindex-29 with the generic SF-36 combines the merits of both types of questionnaires and we therefore recommend this combination.