Counting disability: global and national estimation

To improve the quality of disability information, the World Report recommends the use of a common definition and concepts of disability based on WHO's International Classification of Functioning Disability and Health (ICF). Furthermore, disability measurement needs to apply a multidimensional approach, in particular, measuring disability in terms of the level of difficulty a person is experiencing in multiple areas of life, rather than head counting severe impairment types in a dichotomous way. Environmental factors have significant effects on individual functioning and should be considered as an integral part in disability measurement.