Functioning and disability

World Health Organization Disability Assessment Schedule (WHODAS 2.0)

The WHODAS 2.0 is a generic instrument that can provide population-based measurements of functioning and disability or measurements in clinical practice (Information sheet 16, Questionnaire 14). It measures the level of functioning in six fields, i.e. cognitive, mobility, personal care, relations with others, day-to-day activities, and social participation. The full version comprises 36 questions and the short version, 12. This instrument possesses sound psychometric properties (MacLeod et al., 2016; Üstün et al., 2010). What is more, it is included in the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as an emerging instrument and a replacement for the Global Assessment of Functioning (GAF). This instrument has been used in several major health surveys, including the World Mental Health Survey. The short version, the 12-item WHODAS 2.0, was used in the 2012 Canadian Community Health Survey (CCHS) – Mental Health (Sjonnesen et al., 2016).

Social functioning questionnaire (SFQ)

The 16-item QFS measures two facets of social functioning, i.e. the frequency of behaviour and satisfaction with such behaviour (Information sheet 17, Questionnaire 15) (Zanello et al., 2006). It evaluates eight fields, i.e. activities, everyday tasks, leisure activities, family and marital relationships, extrafamilial relationships, financial and administrative management, general health and communal life and information. In order for a disorder to be diagnosed according to the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), it must affect social functioning in at least one field or arouse significant distress. That is why the measurement of social functioning is central to the evaluation of psychopathology, or its absence.

Other questions related to disability

Statistics Canada has developed validated questions to measure disability. The committee of experts did not evaluate the questions, since they do not constitute a validated instrument. However, indicators have been developed based on the modules, some of which the Infocentre de santé publique disseminates, and thus allow for comparisons over time. Consequently, the questions could serve as alternatives to the instruments recommended earlier (WHODAS, SFQ) if the latter do not satisfy the needs of the survey to be conducted.

Three modules in the Canadian Community Health Survey (CCHS) measure functioning and disability. The first one, “Activities of daily living” (Questionnaire 16), examines the impact of a physical or mental disorder on ordinary activities of daily living such as preparing meals, shopping, and performing housekeeping duties. The six-item module is found in several cycles of the CCHS (Table 4).

The six-item second module, “Activity limitation” first measures difficulties in hearing, seeing, communicating, walking, and so on. The other questions then measure whether activities are reduced (a) in the home, (b) at work or school, and (c) in other activities (Questionnaire 17). This module is also found in several cycles of the CCHS (Table 4). Statistics Canada has developed the two CCHS modules (“Activities of daily living” and “Activity limitation”) based on the International Classification of Functioning, Disability and Health (ICF) (MacKenzie, Husrt, and Crompton, 2010).

The CCHS also contains questions that allow for the production of another disability indicator, “Health utility index,” sometimes called the “Generic health status index.” The indicator describes an individual’s overall functional health based on eight attributes, i.e. vision, hearing, speech, mobility (ability to move about), dexterity (use of the hands and fingers), emotion (feelings), cognition (memory and thinking), and pain. The version used in the CCHS is adapted from the HUI Mark 3 (HUI3). It is possible to produce an overall score or eight scores for the individual attributes. This module is very long (31 items) and statistics from these indicators (overall score or sub-indices) are not available from the Infocentre (Statistics Canada, 2018). This questionnaire is not included in the toolkit.