Generating comprehensive functioning and disability data worldwide: development process, data analyses strategy and...

Area of Science:

• Public Health
• Rehabilitation Science
• Disability Studies

Background:

• Population-level data on functioning and disability are crucial for estimating rehabilitation needs and monitoring international agreements like the Convention on the Rights of Persons with Disabilities (CRPD) and Sustainable Development Goals (SDGs).
• Existing data often complement, but do not fully capture, mortality and morbidity information.
• Accurate measurement of functioning and disability is essential for evidence-based policy and service planning.

Purpose of the Study:

• To report the development process of the World Health Organization (WHO) Model Disability Survey.
• To outline the data analysis strategy employed for the survey.
• To assess the reliability and measurement capabilities of the survey across various levels of functioning and disability in different countries.

Main Methods:

• A detailed description of the survey's development process.
• Secondary data analysis utilizing Rasch methods to evaluate reliability and targeting.
• Inclusion of data from eight national and two regional implementations of the survey.

Main Results:

• The currently available versions of the WHO Model Disability Survey are presented.
• The survey demonstrates good to very good internal reliability across all participating countries.
• The survey exhibits good targeting, effectively measuring functioning and disability levels in diverse populations.

Conclusions:

• The survey's strong psychometric properties are attributed to its participatory development, stakeholder expertise integration, and use of existing ICF-based tools.
• The WHO Model Disability Survey has been implemented in multiple countries, including Afghanistan, Cameroon, Chile, Costa Rica, India, Laos, Pakistan, Philippines, Sri Lanka, and Tajikistan.
• The survey serves as a vital tool for informing policy, monitoring the CRPD and SDGs, and planning rehabilitation services globally.