Quality of life

World Health Organization Quality of Life (WHOQOL-BREF)

The committee of experts recommends the WHOQOL-BREF instrument to assess individual quality of life (Information sheet 18). This 26-item instrument measures four fields, i.e. physical health, mental health, social relations and the environment. The analysis is based on the scores generated for each field (no overall score can be calculated). The user manual is comprehensive, which makes the instrument easy to use (WHO, 1996). While some studies call into question the construct validity (D’Abundo et al., 2011), the WHOQOL-BREF is generally recognized as a reliable, valid instrument to assess quality of life and is widely used in the literature for clinical and population-based surveys (Oliveira, Carvalho and Esteves, 2016; Skevington, Lotfy and O’Connell, 2004). Since this instrument is protected, the English and French questionnaires are not included in this toolkit. Authorization must be sought before using the instrument.

EuroQol-5-Dimension (EQ-5D-5L)

The EuroQol Group has developed three tools to evaluate health status. The most recent instrument is the six-item EQ-5D-5L (Information sheet 19) (Ramos-Goñi et al., 2017). It measures five dimensions (5D), i.e. mobility, personal care, day-to-day activities, pain and discomfort, and depression. The last item of the instrument, called Eq-VAS, is an image of a graduated scale from 0 to 100 that allows the respondent to circle his perception of his current level of health. Since the visual image and its dimensions must be maintained, it is recommended to respond to this instrument on the printed or Web version or in a paper-based face-to-face interview. This tool is very useful in medico-economic surveys. It offers considerable flexibility in the analysis of results, either by presenting the results for each dimension or by creating an index that allows for comparative analyses by mean or by multivariate model. A reference database also exists, including that of the population of Canada, which facilitates comparisons (Xie et al., 2016). However, this instrument is protected and requires registration on the group’s website. Fees may be levied depending on the type of study conducted. The questionnaire is not included in the toolkit.

SF-12v2 Health Survey

The SF-12v2 is the second version, updated in 2000, of the SF-12. The SF-12 and the Sf-12v2 assess quality of life based on 12 items that are derived from the 36-item version (Information sheet 20). It determines a respondent’s profile in eight fields: physical function, physical role, physical pain, general health, vitality, social functioning, emotional role, and mental health. The second version is already well documented in the literature. The first version is still widely used. The method of calculating the SF-12 indices is more complicated than the other two instruments mentioned earlier. While the questionnaire is readily accessible online, the instrument is protected and authorization must be requested beforehand to use it. For this reason, the questionnaire is not included in this toolkit.