The SF-36 consists of 36 questions and is a general health questionnaire assessing the patient’s health status using 8 different dimensions. Those are:
When evaluating the SF-36 questionnaire, it is important to consider which version of the questionnaire is used, as there may be decisive differences between v1.0 and v2.0 concerning the scoring.
For evaluation of the SF-36 questionnaire v1.0, all answers are first converted into predetermined points using a scoring key. The average score of all questions of the respective health dimension, e.g. physical health, is then calculated so that 8 average scores are obtained for the 8 dimensions. These describe the patient’s state of health in the respective dimensions, which can then be assessed using comparison tables.
The possible score ranges from 0 to 100 points. 0 points represent the greatest possible limitation of health, while 100 points represent the absence of health restrictions.6
For evaluation of SF-36 v2.0 no publicly accessible information is available (see license).
In 2009, a systematic review showed that the SF-36 is the most widely used patient reported outcome (PRO) instrument in clinical trials. It is thus one of the most established PRO scores in medicine and its validity has already been proven in numerous studies.1,2,7-11 It is also available in over 170 languages.12
Containing 36 questions, the SF-36 is relatively lengthy compared to other general health surveys. One study showed that patients were able to answer an average of 5 questions per minute.13 Thus, it would take approximately 7 minutes to complete the SF-36 . Spending that much time answering a questionnaire is realistic in a research setting, but needs good time management, e.g. via electronic recording, to be of use in clinical practice..
The use of SF-36 v1.0 does not require licensing and is therefore free of charge.14 For the SF-36 v2.0 however, a license is required. The question of whether this involves costs is not discussed on the website of the rights holder. In our opinion, this is to be expected though.15
The SF-36 questionnaire is a globally established, validated and frequently used questionnaire that is used in various medical disciplines. It therefore has great clinical relevance and will presumably maintain it’s relevance in the future.