Related Experiment Video
Updated: Aug 8, 2026
Measuring Psoriasis Severity at Home
Published on: March 1, 2024
The norwegian version of the psoriasis disability index--a validation and reliability study
1Department of Public Health and Primary Health Care, University of Bergen, Norway. astrid.klopstad.wahl@hibu.no
Objective:
The aim of this study was to translate the Psoriasis Disability Index (PDI) into Norwegian and validate it in a Norwegian setting. The PDI is a measure that was developed to assess the impact of psoriasis on the patient's life.
Methods:
Two hundred and eighty-two patients with psoriasis were included in the study (80% outpatients, and 20% hospitalized).
Results:
Face and content validity were assessed as satisfactory. The PDI seems to capture issues of importance to patients. The results indicate that the PDI does not capture a unidimensional concept. A factor analysis (principal component with orthogonal rotation) resulted in three factors (physical, social, and hygienic) that were substantially different. All three factors had satisfactory internal consistency. Altogether they explained 58% of the variance. In addition, there were differing patterns of correlations with external criteria, such as dimensions of SF-36, as well as with sex, age, and education.
Conclusions:
The PDI has been found to have acceptable reliability in this study. However, further validation is necessary to estimate the sensitivity to change.
