Ewch i’r prif gynnwys

Dermatology Life Quality Index

Mae'r cynnwys hwn ar gael yn Saesneg yn unig.

The Dermatology Life Quality Index (DLQI) is a simple, self-administered and user-friendly validated questionnaire.

The DLQI is designed to measure the health-related quality of life of adult patients suffering from a skin disease.

About the questionnaire

Published in 1994, the DLQI was the first dermatology-specific quality of life questionnaire. The DLQI consists of 10 questions concerning patients' perception of the impact of skin diseases on different aspects of their health-related quality of life over the last week.

It has been used in many different skin conditions in over 80 countries and is available in over 110 translations. Its use has been described in over 3,000 publications, including many multinational studies.

The DLQI is the most frequently used patient reported outcome measure in randomised controlled trials in dermatology.

Who can use it

The DLQI can be used for routine clinical purposes by patients and clinicians to assist the consultation, evaluation and decision-making process.

It can also be used in a range of settings by pharmaceutical companies, with-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 and pay a fee.

Learn more about who can use this questionnaire and how to administer it.

Age range

The DLQI is designed for use in adults, i.e. patients aged 16 years and over.

Time for completion

The average completion time of the DLQI is two minutes. Usually no assistance is required.

Recall period

The questions are designed to be completed with a one week recall period (i.e. last seven days). The DLQI is self-explanatory and can be simply handed to the patient who is asked to fill it in. There is no need for detailed explanation.

Frequency of use

As the time frame of the DLQI questions is over the last week, there should be at least seven days 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

The DLQI is available in Word and PDF formats.

The zip files contain several different versions of the language (depending on what country), along with the translation certificates.

FileDogfen

Dermatology Life Quality Index (DLQI) - original UK English version

14 Mawrth 2019

The original version of the questionnaire, which is designed to measure the health-related quality of life of adult patients suffering from a skin disease.

DownloadLawrlwytho

FileDogfen

Dermatology Quality of Life Index (DLQI) - USA English and other English versions

4 Mawrth 2019

This questionnaire is available in American, Australian, New Zealand and Nigerian English.

DownloadLawrlwytho

Validated DLQI app

If your study includes smartphones or tablets running Android, you can also use our free, validated DLQI app, Psoriasis 360, to administer the questionnaire.

The app itself is not editable, and we're unable to provide access to the back-end data; patient scores would have to be recorded and analysed on an external database.

Scoring, validation and utility values

Each question is scored on a four-point Likert scale:

  • Very much = 3
  • A lot = 2
  • A little = 1
  • Not at all = 0
  • Not relevant = 0
  • Question unanswered = 0

The DLQI is calculated by adding the score of each question, resulting in a maximum of 30 and a minimum of 0. The higher the score, the more quality of life is impaired. A score higher than 10 indicates that the patient's life is being severely affected by their skin disease.

The score can be expressed as a percentage of the maximum possible score of 30, but we don't recommend this, because the original score is much easier to understand.

The scores associated with the different answers should not be printed on the DLQI itself, as this might cause bias.

Scoring question 7

The first part of question 7 asks: 'Over the last week, has your skin prevented you from working or studying?'

If working or studying are not relevant to the subject, the response is 'Not relevant' (scored 0).

If the skin disease has prevented the subject from working or studying, the answer is 'Yes'. As 'prevention' is the biggest possible impact it is scored the maximum, 3.

If the skin disease has not prevented the subject from working or studying, the answer is 'No'. It is therefore assumed that as the skin disease has not prevented the subject from working or studying, the subject is able to continue to work or study, but that the skin disease may be a problem while doing so.

The subject is therefore asked the following question about the magnitude of the impact thus: 'If "No" (in other words 'If the skin disease has not prevented you from working or studying”), over the last week how much has your skin been a problem at work or studying?'

There are three possible responses to the question 'How much has your skin been a problem at work or studying': 'A lot' (scored 2), 'A little' (scored 1) or 'Not at all' (scored 0).

Meaning of scores

  • 0-1 = no effect at all on patient’s life
  • 2-5 = small effect on patient’s life
  • 6-10 = moderate effect on patient’s life
  • 11-20 = very large effect on patient’s life
  • 21-30 = extremely large effect on patient’s life

Minimal clinically important difference (MCID)

For general inflammatory skin conditions, a change in DLQI score of at least four points is considered clinically important.

Sub-scales

The Dermatology Life Quality Index can be analysed under six sub-scales:

SectionQuestionsScore
Symptoms and feelings Questions 1 and 2 Maximum  6
Daily activities Questions 3 and 4 Maximum 6
Leisure Questions 5 and 6 Maximum 6
Work and school Question 7 Maximum 3
Personal relationships Questions 8 and 9 Maximum 6
Treatment Question 10 Maximum 3

The scores for each of these sections can also be expressed as a percentage of either 6 or 3.

Missing data

If one question is unanswered, this is allocated a score of 0 and the DLQI score summed in the usual way, out of 30. If two or more questions are unanswered, the questionnaire is not scored.

It has been suggested that if there are one or more questions unanswered, an adjusted score should be calculated based on the percentage of the maximum score possible. We don't recommend this, and our reasons are given in the publication:

Finlay AY, Sampogna F. What do scores mean? Informed interpretation and clinical judgement are needed .Br J Dermatol 2018; 179: 1021-1022.

The DLQI and the translations are extensively validated.

The original publication covers the initial validation process:
Finlay AY, Khan GK. Dermatology Life Quality Index (DLQI): A simple practical measure for routine clinical use. Clinical and Experimental Dermatology 1994; 19: 210-216.

This review article covers multiple aspects of validation data up to 2008:
Basra MKA, Fenech R, Gatt RM, Salek MS, Finlay AY. The Dermatology Life Quality Index 1994-2007: a comprehensive review of validation data and clinical results. Br J Dermatol. 2008; 159:997-1035.

Since 2008, there have been many publications which address various aspects of validation of the DLQI, best accessed by searching PubMed or Google Scholar using the search term 'DLQI'.

To find dermatology publications about quality of life from Cardiff University, you can search ORCA, the University's digital repository of its research outputs, or search PubMed, by using the author search term ‘Finlay AY'.

Although the DLQI is a dermatology-specific measure, it is possible using a mapping technique and ordinal logistic regression to generate quality adjusted life years (QALYs) from DLQI data.

For more information, please see:

Ali FM, Kay R, Finlay AY, Piguet V, Kupfer J, Dalgard F, Salek MS. Mapping of the DLQI scores to EQ-5D utility values using ordinal logistic regression. Qual Life Res 2017; 26(11): 3025-3034.

An Excel spreadsheet is freely available for researchers who may be interested in generating utility values from DLQI data. Please email Dr Faraz Ali for a copy of this spreadsheet at alifm@cardiff.ac.uk.

In this study, the predicted utilities were not assigned by using cut-offs. We calculated probabilities based on the fitted ordinal logistic models for each EQ-5D domain and each outcome within that domain. Using Monte-Carlo simulation, we then obtained outcomes for each subject on each domain and predicted utilities for each subject based on these outcomes.

The mapping algorithm was tested on a European dataset and not specifically on a UK population. Though there may be cultural variation influencing health-related quality of life (HRQoL) and utility responses, we have not tested this specific question in detail.

However, when our model was created using only Italian patients and tested on a Norway population, it performed almost as well as the model derived from the complete dataset.

Our experience suggests that within the European context there is some uniformity of attitudes, cultural norms and responses, as the DLQI has undergone over one hundred validated translations, with many in continental European countries.

As no official European Time Trade-Off (TTO) values exist for EQ-5D health states, we applied the UK TTO values throughout the validation process.

We are not aware of any similar exercise being carried out for any of the other University dermatology quality of life questionnaires.

Copyright

The DLQI is protected under copyright, so you must not change the format, wording or design of the questionnaire.

The copyright statement must always be reprinted at the end of every copy of the questionnaire in whatever language. On electronic formats the copyright statement must be clearly visible to users:

© Dermatology Life Quality Index. A Y Finlay, G K Khan, April 1992

The authors of the DLQI were Professor A Y Finlay and Dr G K Khan. By agreement, the University now owns and administers all copyright matters relating to the DLQI.

The USA Library of Congress Registration

Number: TXU 608406
Registration date: 6 December 1993
Authors: Professor A Y Finlay and Dr G K Khan

The USA has reciprocal copyright agreements with most countries in the world, thereby establishing worldwide copyright of the DLQI.

Publications

Original publication

Finlay, A. Y. and Khan, G. K. 1994. Dermatology Life Quality Index (DLQI)--a simple practical measure for routine clinical use. Clinical and Experimental Dermatology 19 (3), pp.210-216. (10.1111/j.1365-2230.1994.tb01167.x )

Other key publications

Contact us

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

Joy Hayes

Licencing enquiries

Swyddfa Trosglwyddo Technoleg

If you need to contact Professor Finlay

Professor Andrew Finlay