Field-testing of the rapid assessment of disability questionnaire.

BACKGROUND: The Rapid Assessment of Disability (RAD) questionnaire measures the magnitude and impact of disability and aims to inform the design of disability inclusive development programs. This paper reports the psychometric evaluation of the RAD. METHODS: The initial version of the RAD comprised five sections: 1) demographics, 2) functioning, 3) rights awareness, 4) well-being, and 5) access to the community. Item functioning and construct validity were assessed in a population-based study in Bangladesh. Data were analysed using descriptive statistics (sections 2 and 5) and Rasch modelling (sections 3 and 4). A subsequent case-control study in Fiji tested the refined questionnaire in a cross-cultural setting and assessed the sensitivity and specificity of the RAD section 2 to identify people with disability. RESULTS: 2,057 adults took part in the study (1,855 in Bangladesh and 202 in Fiji). The prevalence of disability estimated using RAD section 2 in Bangladesh was 10.5% (95% CI 8.8-12.2), with satisfactory sensitivity and specificity (62.4% and 81.2%, respectively). Section 3 exhibited multidimensionality and poor differentiation between levels of rights awareness in both Bangladesh (person separation index [PSI] = 0.71) and Fiji (PSI = 0.0), and was unable to distinguish between people with and without disability (Bangladesh p = 0.786, Fiji p = 0.43). This section was subsequently removed from the questionnaire pending re-development. Section 4 had good ability to differentiate between levels of well-being (PSI = 0.82). In both countries, people with disability had significantly worse well-being scores than people without disability (p < 0.001) and also access to all sectors of community except legal assistance, drinking water and toilets (p < 0.001). CONCLUSIONS: Filed-testing in Bangladesh and Fiji confirmed the psychometric robustness of functioning, well-being, and community access sections of the RAD. Information from the questionnaire can be used to inform and evaluate disability inclusive development programs.

A comparative review of measurement instruments to inform and evaluate effectiveness of disability inclusive development.

PURPOSE: A review of existing measurement instruments was conducted to examine their suitability to measure disability prevalence and assess quality of life, protection of disability rights and community participation by people with disabilities, specifically within the context of development programs in low and middle-income countries. METHODS: From a search of PubMed and the grey literature, potentially relevant measurement instruments were identified and examined for their content and psychometric properties, where possible. Criteria for inclusion were: based on the WHO's International Classification of Functioning Disability and Health (ICF), used quantitative methods, suitable for population-based studies of disability inclusive development in English and published after 1990. Characteristics of existing instruments were analysed according to components of the ICF and quality of life domains. RESULTS: Ten instruments were identified and reviewed according to the criteria listed above. Each version of instruments was analysed separately. Only three instruments included a component on quality of life. Domains from the ICF that were addressed by some but not all instruments included the environment, technology and communication. CONCLUSION: The measurement instruments reviewed covered the range of elements required to measure disability-inclusion within development contexts. However no single measurement instrument has the capacity to measure both disability prevalence and changes in quality of life according to contemporary disability paradigms. The review of measurement instruments supports the need for developing an instrument specifically intended to measure disability inclusive practice within development programs. Implications for Rehabilitation Surveys and tools are needed to plan disability inclusive development. Existing measurement tools to determine prevalence of disability, wellbeing, rights and access to the community were reviewed. No single validated tool exists for population-based studies, uses quantitative methods and the components of the ICF to measure prevalence of disability, well-being of people with disability and their access to their communities. A measurement tool that reflects the UNCRPD and addresses all components of the ICF is needed to assist in disability inclusive development, especially in low and mid resource countries.