Mapping the osteoarthritis knee and hip quality of life (OAKHQOL) instrument to the international classification of functioning, disability and health and comparison to five health status instruments used in osteoarthritis

Objectives. To map the content of the OsteoArthritis Knee and Hip Quality Of Life (OAKHQOL) scale to the International Classification of Functioning, Disability and Health (ICF). To compare the OAKHQOL with other instruments used in OA using the ICF core set for OA (OA core set). Methods. We mapped the 43 items of the OAKHQOL to ICF categories according to published linking rules. We used the OA core set to compare the linked OAKHQOL to available ICF linking results for five health status instruments frequently used in OA. Results. The 43 items of the OAKHQOL encompass 51 concepts linked to 27 different second-level ICF categories. Of the 55 OA core set categories, 20 could be linked to the OAKHQOL. Among the body function categories, several items describe sleep, pain and emotional function. Only 3 of 19 ICF activity and participation categories are not covered by the OAKHQOL. ICF environmental factors explored by the OAKHQOL include several important categories: drugs, products for personal use, support and relationships. The health status instruments that most comprehensively cover the OA core set are the OAKHQOL and the AIMS2-SF. All instruments address pain and restrictions in activity and participation but, except for the OAKHQOL and the AIMS2-SF, seldom cover emotional and sleep functions, participation in work and social life, and environmental factors. Conclusion. Compared with other health status instruments commonly used in OA, the OAKHQOL covers the highest number of OA core set categories and captures specific aspects that are especially valuable to patients with knee and hip OA.