The DLQI is a simple self-administered, easy and user-friendly validated questionnaire used to measure the health-related quality of life of adult patients suffering from a skin disease. Developed in 1994, the DLQI was the first dermatology-specific Quality of Life instrument. The DLQI may be used for routine clinical use by clinicians in order to assist the clinical consultation, evaluation and clinical decision making process.
It 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 validated for adult dermatology patients aged 16 years and older. The items of the DLQI encompass aspects such as symptoms and feelings, daily activities, leisure, work or school, personal relationships and the side effects of treatment.
Each question is scored on a 4-point Likert scale: Not at all/Not relevant=0, A little=1, A lot=2 and Very much=3. Scores of individual items (0-3) are added to yield a total score (0-30); higher scores mean greater impairment of patient's QoL.
The average completion time of the questionnaire is 2 minutes.
The DLQI has been used in at least 33 different skin conditions in over 32 countries and is available in over 85 language versions. Its use has been described in over 800 publications including 30 multinational studies. The DLQI is the most frequently used quality of life instrument in randomised controlled trials in dermatology.
Yes, the DLQI may be used for routine clinical use by clinicians in order to assist the clinical consultation, patient evaluation and monitoring and to help with clinical decision making process.
Yes, the DLQI may be used by individual patients in order to help their communication with their physicians. There is no need to ask for permission and there is no charge.
The DLQI is a simple, self-administered, easy and user-friendly questionnaire with an average completion time of 2 minutes.
There is no need to seek specific permission for using the DLQI in routine clinical practice and there is no charge for the use of the DLQI in this context. However it is a requirement that every copy of the DLQI, in whatever language, should always reprint at the end of the DLQI, the following copyright statement:
© A Y Finlay, G K Khan April 1992 www.dermatology.org.uk
For the use of the instrument in research studies and for other purposes, formal permission must be sought from the original copyright holders of the DLQI before the start of the study.
There is a simple method for getting formal permission for use of the DLQI. Formal permission is usually given immediately. Please e-mail to one of the following contacts:
For general queries, technical aspects and permission to use:
E-mail: dermqol@cf.ac.uk
Other contacts:
Mrs Joy Hayes (contractual financial aspects): HayesJ@cf.ac.uk
Professor Andrew Y Finlay: FinlayAY@cf.ac.uk
Address:
Department of Dermatology
Cardiff University School of Medicine
Heath Park, Cardiff
CF14 4XN
United Kingdom
Te: +44 (0)29 2074 2884
Fax: +44 (0) 29 2074 4321
The scoring of each answer is as follows:
Very much scored 3 A lot scored 2 A little scored 1 Not at all scored 0 Not relevant scored 0 Question unanswered scored 0 Question 7: "prevented work or studying" scored 3
The DLQI is calculated by adding the score of each question. The maximum score is 30 and the minimum is 0. The higher the score, the more quality of life is impaired. The DLQI can be expressed as a percentage of the maximum possible score of 30 but we do not recommend this because the "original" score is much easier to understand.
Please Note: The scores associated with the different answers should not be printed on the DLQI itself, as this might cause bias.
Meaning of DLQI 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
Detailed analysis of the DLQI
The DLQI can also be analysed under six headings or dimensions as follows:
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Questions 1 and 2 | Score maximum 6 |
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Questions 3 and 4 | Score maximum 6 |
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Questions 5 and 6 | Score maximum 6 |
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Question 7 | Score maximum 3 |
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Questions 8 and 9 | Score maximum 6 |
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Question 10 | Score maximum 3 |
The scores for each of these sections can also be expressed as a percentage of either 6 or 3.
There is a very high success rate of accurate completion of the DLQI. However, sometimes subjects do make mistakes.
- If one question is left unanswered this is scored 0 and the scores are summed and expressed as usual out of a maximum of 30.
- If two or more questions are left unanswered the questionnaire is not scored.
- If question 7 is answered 'yes' this is scored 3 even if in the same question one of the other boxes is ticked.
- If question 7 is answered 'no' or 'not relevant' but then either 'a lot' or 'a little' is ticked this is then scored 2 or 1.
- If two or more response options are ticked for one question, the response option with the highest score should be recorded.
- If there is a response between two tick boxes, the lower of the two score options should be recorded.
- The DLQI can be analysed by calculating the score for each of its six sub-scales (see above). When using sub-scales, if the answer to one question in a sub-scale is missing, that sub-scale should not be scored.
"Not relevant" is always scored 0.
"Not at all" is always scored 0.
The only place in the questionnaire that has "No" as an option is in the first part of question 7. There is no score associated with "No". This is because it is expected that if a patient answers "No" in the first part of question 7, they would then go on and answer the second part of question 7, for which there are three options, scored 2, 1, or 0. (If they answer "Yes" to the first part of question 7, this is scored 3.)
In question 7 if a participant has marked both "No" and "Not relevant", this scores 0.
If in the other questions they mark both "Not at all" and "Not relevant", this scores 0.
The questions of the DLQI have been phrased to ask patients about the QoL impact over the last one week, a duration considered to be easily and accurately recallable.
The DLQI has been created as a single index. However, arbitrarily the 10 questions can be categorised (and analysed) under six subscales or dimensions as follows:
- Symptoms and feelings
- Daily activities
- Leisure
- Work and School
- Personal relationships
- Treatment
The DLQI can be analysed under the six subscales or dimensions as follows:
|
Questions 1 and 2 | Score maximum 6 |
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Questions 3 and 4 | Score maximum 6 |
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Questions 5 and 6 | Score maximum 6 |
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Question 7 | Score maximum 3 |
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Questions 8 and 9 | Score maximum 6 |
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Question 10 | Score maximum 3 |
The scores for each of these sections can also be expressed as a percentage of either 6 or 3.
The DLQI scores range from 0 to 30; lower scores indicate lower impairment of patient's quality of life and higher scores indicate greater impairment of patient's quality of life. A simple guide to show the meaning of different DLQI scores is as follows:
DLQI score 0-1 = no effect at all on patient's life
DLQI score of 2-5 = small effect on patient's life
DLQI score of 6-10 = moderate effect on patient's life
DLQI score of 11-20 = very large effect on patient's life
DLQI score of 21-30 = extremely large effect on patient's life
Furthermore, a change in scores is considered clinically meaningful, when a patient's DLQI scores have changed by at least 4 points from the previous reading (this figure is based on our published data).
The time frame of the DLQI questions is based on quality of life estimation over the last one week. This means that the DLQI can be used as frequently as required but there should be at least 7 days between each use. However, very frequent use is not recommended because of the possibility that the patient will remember and be influenced by previous answers or become less careful with answering.
The DLQI has been designed and validated for individuals 16 years of age and older.
First check on this website that the language translation is not already available. It is necessary to seek permission from Professor Finlay or colleagues before starting to undertake a translation of a QoL questionnaire authored by them. This is to ensure that a translation into that language is not already underway and that appropriate steps are followed to ensure a validated translation process.
At the very minimum, two independent translators need to translate the measure (e.g. DLQI) from English into the alternative language. These two translators then discuss their translations and agree on a single translation in the alternate language. A third and fourth translator are then asked to independently back-translate the agreed alternate language version into English.
At this stage the back-translations need to be reviewed by the copyright holders (Prof Andrew Y Finlay and colleagues). Nearly always small problems become apparent and it is usually necessary for further changes to be made in the alternative language translation. This then needs to be validated by a further process of back-translation. Advice on this process can be gained either from Professor Finlay or colleagues. Finally the agreed translation has to be pretested in a group of potential subjects in a process called cognitive debriefing.
Cognitive debriefing:
In brief, you enrol a small number of patients (e.g. 5 to 8) representing the population that would be completing the questionnaire in future. Ask them to complete the questionnaire, note the time needed to complete, ask them about the clarity, understandability, wording of the questions, is there any question that might need changing the wording and whether the questions are easily comprehensible, or not clear enough. Ask the same about the response categories. In case the respondents raise any issues about the wording or the format of the questions, ask them their opinion on how to improve this. You have to do this for every single question, one by one.
There is no need for a control population in this process; however the target population has to be representative of the population in whom the questionnaire will be used.
Copyright statement
The original English copyright statement or a validated translation of that copyright statement must always be reproduced at the end of every translation. The copyright for any translation is retained by the original copyright holders and is not transferred or shared with any additional person or institution even though they may have been involved in the translation.
We usually require a final report describing the process before approving the final version of the translation to be used. The final agreed translation is then placed on our website for others to also use.
Summary
Steps involved in the whole process of translation and linguist validation include:
- Preparation
- Forward Translation
- Reconciliation
- Back Translation
- Back Translation Review
- Harmonisation
- Pilot Testing/Cognitive Debriefing
- Review of Cognitive Debriefing Results and Finalisation
- Final Report
It is not possible to change the current content, wording, or question sequence of the DLQI. Please remember that any change carried out to the DLQI would be considered a violation of international copyright laws.
If you would like to reformat the DLQI design to adapt it to your study needs, we would be happy to discuss this with you (please contact us). However, please note that the copyright for this will remain entirely as for the original version of the DLQI and that the copyright statement must be reproduced on the new format.
Please note also that it will be necessary for the original copyright holder to approve of the final format and it would therefore be necessary for you to let us have copies of the draft version before approval.
Please note that there should not be any pharmaceutical company identifier printed in relationship to any new formatting of the DLQI. In other words there should not be any text or symbols which might give the incorrect impression that the DLQI is in some way owned or associated with a particular pharmaceutical company.
The DLQI may be used for routine clinical use by clinicians in order to assist the clinical consultation, evaluation and clinical decision making process. There is no need to seek specific permission for this and there is no charge for the use of the DLQI in this context. However it is a requirement that every copy of the DLQI, in whatever language, should always reprint at the end of the DLQI, the following copyright statement
© A Y Finlay, G K Khan April 1992 www.dermatology.org.uk
The above permission does not affect the requirement for seeking of permission and of possible payment when the DLQI is used for research or other purposes.
There is a small charge for the use of the DLQI (Except where the DLQI is used for routine clinical purposes). This charge in clinical research studies is based upon the total number of patients to whom the Index is administered. It is not based upon the frequency with which the questionnaires are administered to each individual patient.
These charges are always waived by the copyright holders for non-funded 'academic' studies and they are mainly applied to pharmaceutical companies using these Indexes in Phase II and Phase III studies. Please contact the authors concerning this. The charge per patient is as follows:
UK: £5.00
USA and rest of world: $9.50
Payment should be made upon receipt of an invoice from Cardiff University.
If you are considering using the DLQI in your routine clinical practice, you can straightaway download the instrument in any language from our website (www.dermatology.org.uk). There is no need to obtain formal permission and there is no charge.
If you are considering using the DLQI for an academic research study not funded by a commercial pharmaceutical company or an external funding source, you should write to us for formal permission for its use at: dermqol@cf.ac.uk. Once you have got the formal permission from us, then you would be allowed to download the instrument directly from our website (www.dermatology.org.uk).
If you are considering using the DLQI for a clinical study funded by an external source such as a commercial pharmaceutical company, you would need to write to us to seek formal permission. You should let us know the exact number of patients you are planning to administer the DLQI to. We will then send you a contract and an invoice for payment, and we will give you the formal permission to use the DLQI. Following this you would be allowed to download the instrument directly from our website for use in the study (www.dermatology.org.uk).
If you are an undergraduate student (for example a medical student) or a postgraduate student undertaking a higher degree, you can use the DLQI in your research project without seeking permission, provided that the project is not externally funded, for example by a pharmaceutical company. However it is a requirement that all copies of the DLQI, in any language, must reproduce the copyright statement (se above) at the end of every copy of the DLQI.
For clinical use and for academic research studies, there are no charges. However, for externally funded clinical studies, a small charge is applicable. The money generated is used to support quality of life research and other related activities within the Department of Dermatology, Cardiff University.
There is no charge for the use of the DLQI for use in clinics or for academic studies. However, for studies which are funded by pharmaceutical companies the charge is currently £5.00 GB pounds sterling or US $ 9.50 per patient. Please note that for companies based within the European Union, VAT may be payable.
If you have decided to use the DLQI, you will need to write to Mrs. Joy Hayes (see above for contact details). Payment is upon receipt of an invoice from Cardiff University. For this purpose we will need to know the number of patients to be recruited and also the mailing address as to where our invoice should be sent.
The DLQI is copyrighted:
- To protect the integrity of the measure. Because it is copyright we have been able to refuse permission to many requests for alterations to the questionnaire. This has been essential to ensure that the DLQI score integrity has been established and is maintained worldwide.
- To protect the integrity of the DLQI in the many language translations. By maintaining control over the DLQI we have been able to ensure that only fully validated translations are used and that they are freely available on our website.
- To allow some income generation to support quality of life research in dermatology. In particular to support research work enhancing the usefulness and validation of the DLQI and the development of other measures.
The DLQI is copyright world-wide and can only be reprinted with permission from the authors. The need for seeking permission is waived by the copyright holders for use of the DLQI for routine clinical purposes.
Copyright details
The DLQI is copyright under the law of England and Wales. The DLQI is also copyright in the USA:
The USA Library of Congress Registration Number: TXU 608406
Registration Date: 6 December 1993
The USA has reciprocal copyright agreements with most countries in the world thereby establishing worldwide copyright of the DLQI.
Authors
Professor A Y Finlay and Dr G K Khan
The copyright statement
© Dermatology Life Quality Index. A Y Finlay, G K Khan, April 1992 www.dermatology.org.uk. This must not be copied without the permission of the authors.
The copyright statement must always be reprinted at the end of every copy of the questionnaire in whatever language.
For general queries:
dermqol@cf.ac.uk
Other contacts:
Dr. Mohammad K. A. Basra: BasraMK@cf.ac.uk
(Technical aspects and permission to use)
Mrs Joy Hayes (contractual and financial aspects): HayesJ@cf.ac.uk
Professor Andrew Y Finlay: FinlayAY@cf.ac.uk
Address:
Department of Dermatology
Cardiff University School of Medicine
Heath Park, Cardiff
CF14 4XN
United Kingdom
Te: +44 (0)29 2074 2884
Fax: +44 (0) 29 2074 4321
The person responsible for looking after the payments and contractual issues is Mrs Joy Hayes. Her contact details are as follows:
e-mail: HayesJ@cf.ac.uk
Tel: +44 (0)29 2074 2884
Fax: +44 (0) 292074 4312
For details of the published data on the DLQI click here.
The following article is useful as a comprehensive source of different aspects of the DLQI's validation and clinical data up to the end of 2007.
Ref: 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.
In order to help the clinical interpretation of the DLQI scores a banding system (consisting of 5 bands) has been suggested. According to this system:
DLQI score 0-1 = no effect at all on patient's life
DLQI score of 2-5 = small effect on patient's life
DLQI score of 6-10 = moderate effect on patient's life
DLQI score of 11-20 = very large effect on patient's life
DLQI score of 21-30 = extremely large effect on patient's life
The MCID of the DLQI in specific skin diseases (range=2.2-6.9) has been estimated in 5 studies using recommended statistical methods. For details please refer to the following article:
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.
For general skin conditions a change in DLQI score of at least 3.2 points is considered clinically important (based on our latest published data). This means that a patient's DLQI score has to either increase or decrease by at least 3.2 points in order to suggest that there has actually been a meaningful change in that patient's quality of life since the previous measurement of his/her DLQI scores.
The Department of Dermatology's website (www.dermatology.org.uk) has a list of all the publications to date related to the DLQI. Please go to the Quality of Life page of the website to access the list of these publications.
Key references:
- Finlay AY, Khan GK. Dermatology Life Quality Index (DLQI): a simple practical measure for routine clinical use. Clin Exp Dermatol, 1994; 19: 210-216.
- Lewis V L, Finlay A Y. Ten years experience of the Dermatology Life Quality Index (DLQI) J Investig Dermatol Symp Proc, 2004; 9(2):169-180.
- Hongbo Y, Thomas C L, Harrison M A, Salek M S, Finlay A Y. Translating the Science of Quality of Life into Practice: What Do Dermatology Life Quality Index Scores Mean? J Invest Dermatol, 2005; 125: 659-664.
- 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.
- AY Finlay. Current severe psoriasis and the Rule of Tens. Br J Dermatol 2005; 152: 861-867.
For a detailed list of references please click on the link below:
http://www.dermatology.org.uk/quality/quality-dlqi-articles.html
Dermatology Life Quality Index, "DLQI" as the search term is the quickest way to identify very recent publications.
In theory yes, but at present there is no validation of this approach.
Not currently available from this Department.
The Dermatology Life Quality Index questionnaire has been designed and validated for use in adults, i.e. patients over the age of 15. On the other hand, the Children's Dermatology Life Quality Index questionnaire has been designed for use in children, i.e. patients from age 5 to age 16. Like the DLQI, it is self explanatory and can be simply handed to the patient who is asked to fill it in with the help of the child's parent or guardian.
It is not appropriate to place the score numbers next to the answer choices. This is because all of the validation of the questionnaire has taken place without this and it could
be that having the numbers present would alter the way in which the respondents answer. We do not have any validation information concerning the questionnaire with the layout including the score numbers.
If patients answer "Not relevant" this question should be given a score of 0 (as for "Not at all"). It does not matter whether "Not relevant" or "Not at all" is ticked; in either case the score would be zero. The total score should still be out of 30. If "Not relevant" is ticked, this therefore does not affect the final statistical analysis.
Under no circumstances, should respondents be guided to tick one or other option as this could lead to bias. Ideally respondents should complete the questionnaire unaided unless there is some specific confusion and they ask for help in understanding a particular question. In most research studies that have been conducted using the DLQI, most respondents did not find it difficult to complete the questionnaire unaided.
The absolute minimum time is of course one week, because of the questions referring to the last week. However, if the DLQI is to be used repeatedly, it is better not to use it more frequently than once monthly because of patient recall and because of the risk of inducing carelessness or lack of interest in the patient.
It is completely unacceptable to add questions to the DLQI. The DLQI can only be used if the users agree to use the exact wording of the DLQI. If users wish to administer some additional questions in their study, that is up to them, but they must not include additional questions as part of the DLQI.
"Literal translation" means that a translator makes a one way translation from English into the language of that version. This is not acceptable and permission will not be given for such unvalidated and non-approved translations of the DLQI to be used or published. "Literal" one-way translations nearly always contain errors and we will not allow any inaccurate translations to be published.
All translations of the DLQI must be validated through an extensive process of independent forward and backward translations, reconciliation, cognitive debriefing and final approval by the Cardiff team. This is why only the validated translations as given on our website are allowed to be reproduced (with permission).
For undergraduate (e.g. medical student) or postgraduate research projects involving the use of the DLQI, in any language version, you do not need to ask for formal permission and there will not be any charge for its use irrespective of the number of subjects. However, it is a requirement that the copyright statement (© A Y Finlay, G K Khan April 1992 www.dermatology.org.uk) must always be reproduced at the end of every copy of the DLQI questionnaire used. Please also note that for commercially funded research studies, there is a small charge as mentioned on our website (see FAQs).
No, it is not correct to combine DLQI and CDLQI score data. The questions in the two measures are different and the score banding meaning descriptors for the CDLQI and for the DLQI are different. DLQI and CDLQI data should be analysed and presented separately.