Background:
The assessment of functioning and disability is an important part of clinical evaluation, since it measures disease burden and reflects the effectiveness of therapeutic planning and interventions. The aim of the current study was to develop a self-report instrument on the basis of a review of the literature, compatible with the World Health Organization (WHO) approach.
Methods:
The review of the literature led to the development of the Global Disability Scale (GloDiS), with 25 items assessing different aspects of disability. The study sample included 728 persons from vulnerable populations (homeless, jobless, very low income, single parent families and so on (29.12% males and 70.88% females; age 55.96 +/- 15.22 years). The protocol also included the State-Trait Anxiety Inventory (STAI) and the Center for Epidemiologic Studies Depression Scale (CES-D). The statistical analysis included factor analysis, item analysis and analysis of covariance (ANCOVA).
Results:
The factor analysis revealed the presence of four factors explaining 71% of total variance (everyday functioning, social and interpersonal functioning, severity and mental disability). The Cronbach alpha value for the whole scale was 0.95 and for subscales the range of values was 0.74 to 0.94.DiscussionThe results of the current study suggest that the GloDiS has the potential to serve as a reliable and valid tool for assessing functioning and disability. Further research is needed to prove that it could be useful across countries, populations and diseases, and on whether it provides data that are culturally meaningful and comparable. It can be used in surveys and in clinical research settings and it can generate information of use in evaluating health needs and the effectiveness of interventions to reduce disability and improve health.