The Validity and Reliability of Psoriasis Disability Index (PDI) in Thai
Keywords:
Psoriasis disability index, Dermatology Life Quality Index, validity, reliabilityAbstract
Objective: Psoriasis Disability Index (PDI) is a simple and reliable questionnaire to access the quality of life of psoriasis patients. The purpose of this study was to evaluate the validity and reliability of Thai version of PDI.
Materials and Methods: Thai version of PDI and Thai version of Dermatology Life Quality Index (DLQI) were completed by 86 psoriasis patients from the dermatology clinic, Siriraj Hospital. The validity of Thai version of PDI was analyzed by Spearman’s rank correlation. The reliability of Thai version of PDI was accessed by the internal consistency using Cronbach’s alpha coefficient. The severity of psoriasis was evaluated and classified with Psoriasis Area and Severity Index (PASI) score.
Results: The validity was shown by significant correlation between each aspect of Thai version of PDI and DLQI. The moderate to severe group of psoriasis patients had a higher score of PDI than the mild group. The correlation coefficient ranging was 0.50 to 0.74 and Cronbach’s alpha was 0.83. These results indicated good internal consistency.
Conclusions: Thai version of PDI is a valid and reliable questionnaire for measuring the quality of life of Thai patients with psoriasis.
References
Ginsburg IH, Link BG. Psychosocial consequences of rejection and stigma feelings in psoriasis patients. Int J Dermatol. 1993;32:587-91.
Kulthanan K, Jiamton S, Wanitphakdeedecha R, Chantharujikaphong S. The Validity and Reliability of Dermatologyl Life Quality Index (DLQI) in Thais. Thai J Dermatol. 2004;20:113-23.
Finlay AY, Khan GK, Luscombe DK, Salek MS. Validation of Sickness Impact Profile and Psoriasis disability Index in Psoriasis. Br J Dermatol. 1990;123:751-56.
Wahl AK, Wiklund L, Moum T, Hanestad BR. The Norwegian Version of the Psoriasis Disability Index - A Validation and Reliability Study. Value in Health. 1999;2:342-49.
Gladys AM, Arruda L, Mugnaini ASB. Validation of life quality questionnaires for psoriasis patients. An bras Dermatol. 2004;79:521-35.
Schmitt J, Wozel G. The Psoriasis Area and Severity Index is the adequate criterion to define severity in chronic plaque type psoriasis. Dermatology. 2005;210:194-9.
Finlay AY, Kelly SE. Psoriasis - An index of disability. Clin Exp Dermatol. 1987;12:8-11.
Nichol MB, Margonies JE, Lippa E. The application of multiple quality-of-life instruments in individuals with mild to moderate psoriasis. Pharmacoeconomics. 1996;10:644-53.
Gutpa MA, Schork NJ, Gupta AK. Pruritus in psoriasis. A prospective study of some psychiatric and dermatologic correlates. Arch Dermatol. 1988;124:1052-7.
Gutpa MA, Gupta AK. Psoriasis and sex. A study of moderately to severely affected patients. Int J Dermatol. 1997;36:259-62.
Finlay AY, Khan GK. Dermatology Life Quality Index (DLQI) - a simple practical measure for routine clinical use. Clin Exp Dermatol. 1994;19:210-6.
Hahn HB, Melfi CA, Chuang TY. Use of the Dermatology Quality Index (DLQI) in midwestern US urban clinic. J Am Acad Dermatol. 2001;45:44-8.
Yang Y. The psoriasis disability index in Chinese patients: contribution of clinical and psychological variables. International Journal of Dermatology. 2005;44:925-29
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Thai Journal of Dermatology
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
เนื้อหาและข้อมูลในบทความที่ลงตีพิมพ์ในวารสารโรคผิวหนัง ถือเป็นข้อคิดเห็นและความรับผิดชอบของผู้เขียนบทความโดยตรงซึ่งกองบรรณาธิการวารสาร ไม่จำเป็นต้องเห็นด้วย หรือร่วมรับผิดชอบใดๆ
บทความ ข้อมูล เนื้อหา รูปภาพ ฯลฯ ที่ได้รับการตีพิมพ์ในวารสารโรคผิวหนัง ถือเป็นลิขสิทธิ์ของวารสารฯ หากบุคคลหรือหน่วยงานใดต้องการนำทั้งหมดหรือส่วนหนึ่งส่วนใดไปเผยแพร่ต่อหรือเพื่อกระทำการใดๆ จะต้องได้รับอนุญาตเป็นลายลักอักษรจากบรรณาธิการวารสารโรคผิวหนังก่อนเท่านั้น
