Cieza A, Hilfiker R, Boonen A, Chatterji S, Kostanjsek N, Ustün BT, Stucki G.
Items from patient-oriented instruments can be integrated into interval scales to operationalize categories of the International Classification of Functioning, Disability and Health.
J Clin Epidemiol. 2009; 62(9):912-21, 921.e1-3. Abstract