• Users Online: 378
  • Print this page
  • Email this page
Year : 2020  |  Volume : 24  |  Issue : 1  |  Page : 25-32

Psychometric validation of the psoriasis disability index questionnaire (Translated Bengali Version): A cross-sectional study

1 Department of Homoeopathic Materia Medica, National Institute of Homoeopathy, Kolkata, West Bengal, India
2 Department of Case Taking and Repertory, National Institute of Homoeopathy, Kolkata, West Bengal, India
3 Private Practice, Malpora Bomai Sopore, Baramulla, Jammu and Kashmir, India
4 Independent Researchers, Kolkata, West Bengal, India

Correspondence Address:
Dr. Anaitulah Ahmad Mir
Department of Homoeopathic Materia Medica, National Institute of Homoeopathy, Block GE, Sector III, Salt Lake, Kolkata - 700 106, West Bengal
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jdds.jdds_38_19

Get Permissions

Introduction: The Psoriasis Disability Index (PDI) is a pre-validated, self-administered questionnaire assessing quality of life in adults suffering from psoriasis. The English version contains 15 items measuring five components – activities, work/school performance, personal, leisure, and treatment. Purpose: We aimed to translate the PDI into Bengali and examine its psychometric properties. Methods: The PDI-Bengali version (PDI-B) was produced by standardized forward-backward translations. A cross-sectional study was conducted to gather responses by consecutive sampling. Reliability was tested using internal consistency and test-retest reliability analyses, concurrent validity by comparing with Psoriasis Area and Severity Index (PASI) and Dermatological Life Quality Index scores, while construct validity by exploratory factor analysis (n= 83) using principal component analysis (varimax rotation). Subsequently, confirmatory factor analysis (CFA; n = 85) was performed to verify the a priori scales by the goodness of fit model. Results: The internal consistency (Cronbach's alpha) and the intra-class correlation coefficients were 0.877 and 0.882, respectively. Acceptable values of internal consistency, test-retest reliability, and concurrent validity were found. All the items loaded above the pre-specified value of 0.4. Factor analyses using Varimax identified three components (social activities, concern, and personal activities) explaining 56.8% of the variation. The Kaiser-Meyer-Olkin was 0.836 and Bartlett's test of sphericity was P < 0.001. The goodness of fit of CFA model was excellent. Conclusion: The PDI-B, consisting of 15 items and framed within three components, is a valid and reliable questionnaire, but measured different dimensions from the English version.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded278    
    Comments [Add]    
    Cited by others 1    

Recommend this journal