Psoriasis Disability Index
The Psoriasis Disability Index (PDI) questionnaire is designed for use in adults, ie patients over the age of 16.
It is self-explanatory and can be handed to the patient who is asked to fill it in without the need for a detailed explanation.
Who can use it
This questionnaire can be used in a range of settings by clinicians, pharmaceutical companies, for-profit organisations, students or researchers.
Depending on who you are and what you're using the questionnaire for, you may need to apply for a licence. Please note that there is no charge to use the PDI.
To apply for a licence to use the PDI please directly contact Technology Transfer office at email@example.com. It is not possible to apply using our online licensing system.
Learn more about who can use this questionnaire and how to administer it.
Time for completion
The PDI is usually completed in three or four minutes.
The questions are designed to be completed with a four-week recall period. There should be at least four weeks between each use. Very frequent use is not recommended, because you or the patient may remember and be influenced by previous answers or become less careful answering.
Download the questionnaire
Psoriasis Disability Index (PDI) - English version
This questionnaire is designed for patients aged 16 years or over to complete, with a four week recall period.
Different language versions
This zip file contains the questionnaires in different languages, along with the translation certificates. Find out more about our translation and linguistic validation process, and what to do if you'd like to create a new translation.
Psoriasis Disability Index (PDI) - different language versions
Download the questionnaire in several different languages: Arabic, Bosnian, Chinese, Czech, Danish, Filipino, Finnish, French, German, Gujarati, Hindi, Icelandic, Italian, Japanese, Lithuanian, Marathi, Portuguese, Romanian, Serbian, Spanish, Thai, Turkish, Ukranian and Zulu.
How to score it
The score for each question is:
|Not at all||0|
If a question is left unanswered, the score = 0.
The Psoriasis Disability Index is calculated by summing the score of each of the 15 questions, resulting in a maximum of 45 and a minimum of 0.
The higher the score, the more quality of life is impaired. The Psoriasis Disability Index can also be expressed as a percentage of the maximum possible score of 45.
The Psoriasis Disability Index can be analysed under five headings:
|Daily activities||Questions 1, 2, 3, 4 and 5||15|
|Work or school or alternative questions||Question 6, 7 and 8||9|
|Personal relationships||Questions 9 and 10||6|
|Leisure||Questions 11, 12, 13 and 14||12|
Please note that the Psoriasis Disability Index (PDI) is protected under copyright, so you must not change the format, wording or design of the questionnaire.
This statement must always be reproduced at the end of every copy of the PDI:
© Psoriasis Disability Index. A Y Finlay, S E Kelly 1985
Finlay AY, Kelly SE. Psoriasis: an index of disability. Clin Exper Derm, 1987; 12: 8-11.
Original publication of current version
Finlay AY, Coles EC. The effect of severe psoriasis on the quality of life of 369 patients. Brit J Dermatol, 1995; 132: 236-244. (Gives text of current (second) version)
Other key publications
- Finlay AY, Khan GK, Luscombe DK, Salek MS. A validation of Sickness Impact Profile and Psoriasis Disability Index in Psoriasis. Brit J Dermatol, 1990; 123: 751-756. (Second version)
- Lewis VJ, Finlay AY. Two Decades Experience of the Psoriasis Disability Index. Dermatology, 2005, 210:261-268.
If you have any questions, or you have feedback on our web pages, please get in touch.
General queries and feedback
Dr. Faraz Ali
Dermatology Quality of Life Administrator
Financial, contractual or student enquiries
Technology Transfer office
If you need to contact Professor Finlay
Professor Andrew Finlay
We offer a range of postgraduate dermatology courses, delivered both on site in Cardiff and online for distance-learning.