Scale Analysis

The World Health Organization (WHO) developed the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) as a general self-assessment tool for functionality and disability, based on the conceptual framework of the International Classification of Functioning, Disability and Health (ICF). According to the ICF, a biopsychosocial framework is used to describe an individual’s functionality and limitations, regardless of illness, disease, or syndrome.

Purpose of the Scale

WHODAS 2.0 is a practical measure of general performance aimed at describing and examining the impact of disability. It gathers information about functionality that is affected by health conditions and daily life difficulties. Health conditions include diseases or illnesses, temporary or chronic health problems, injuries, mental or emotional issues, as well as problems related to alcohol or drug use.

Question Calibration

WHODAS 2.0 consists of 36 questions in total, categorized into six subscales: Understanding and Communication, Mobility, Self-care, Getting along/Interpersonal Interactions, Life Activities, and Participation in Society. A 5-point Likert scale was used for responses, ranging from 1 (None) to 5 (Extreme or Cannot Do).

Statistical Analysis

Participants, through their responses, indicate the degree of difficulty they experienced while performing the activities in the questionnaire over the past 30 days. The entire questionnaire is answered by all participants, except for a section of the Life Activities subscale, which is only completed by those who are employed or students. The total score ranges from 0 to 100, where 0 indicates no disability and 100 indicates complete disability.

Validity and Reliability

WHODAS 2.0 demonstrates excellent psychometric properties. Studies from countries worldwide have shown it to be highly reliable. The Greek translation was carried out by Koumpouros, Sakellari, Papageorgiou, and Lagiou. Validity studies also showed that it performs well compared to other disability or health status measurement tools, as well as in relation to clinical and other relevant assessments. Cronbach’s alpha values were generally very high. For the six subscales, the alpha coefficient ranged from 0.94 to 0.96, while for the overall WHODAS it was α = 0.98.

References

World Health Organization (WHO)
Greek Translation: I. Koumpouros, E. Sakellari, E. Papageorgiou, and A. Lagiou.