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Rheumatology Advance Access originally published online on September 27, 2008
Rheumatology 2008 47(11):1719-1725; doi:10.1093/rheumatology/ken352
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© The Author 2008. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

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

A.-C. Rat1,2, F. Guillemin1 and J. Pouchot3

1Centre d’Epidémiologie Clinique CIC-EC-INSERM CIE6, Service d‘Epidémiologie et Evaluation Cliniques, 2Service de Rhumatologie, Nancy University, Nancy and 3Service de Médecine Interne, Hôpital Européen Georges Pompidou, Paris, France.

Correspondence to: A.-C. Rat, EA4003, Centre d’Epidémiologie Clinique CIC-EC-INSERM CIE6, Service d’Epidémiologie et Evaluation Cliniques, Hôpital Marin, 2 avenue du Maréchal de Lattre de Tassigny, C.O N°34, 54035 Nancy Cédex, France. E-mail: ac.rat{at}chu-nancy.fr


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 Conclusion
 Acknowledgements
 References
 
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.

KEY WORDS: Quality of life, Osteoarthritis, International classification of functioning, disability and health, Outcome measures


   Introduction
Top
 Abstract
 Introduction
Methods
 Results
 Discussion
 Conclusion
 Acknowledgements
 References
 
In designing a clinical research project, a major issue is to determine what should be measured in respect with the objectives of the study. The second issue is to decide which measures to use. Unfortunately, many studies compare the psychometric properties of instruments but rarely their contents.

The content of different health-related quality of life (HRQoL) measures is not equivalent, which prevents comparison between instruments. Bridging HRQoL scores with clinical care or public health is still difficult because of the need to interpret scores, as well as obtain a precise knowledge of the content of the measure instruments [1].

The International Classification of Functioning, Disability and Health (ICF) is a general health status framework that comprehensively represents the experience of patients [2]. The ICF was developed because diagnosis alone does not predict functional outcomes and services needs, and because data about levels of functioning and disability were lacking. The classification aims to provide a scientific basis to understand and study health states, as well as their consequences and determinants. To analyse the impact of different interventions, classifying areas of life as well as environmental factors that improve performance was important. Indeed, to achieve patients’ treatment goals and improve their satisfaction, it is essential to identify systematically and comprehensively all the patients’ problems, needs, contextual factors and their relations and consequences on participation. The ICF has the advantage of being a universal and standardized language to describe functioning and health. However, it emphasizes what has to be measured but not how to measure. Patient-reported outcome measures are needed to assess repercussions of health problems. The ICF can guide content analysis of new measures and improve our understanding of the structure of existing instruments to aid in the interpretation of their results. Investigators can translate outcome measures into the same language (ICF codes) to compare the content of instruments, thus identifying the instrument that could efficiently address the categories required for the objectives of a planned study [1].

To facilitate the application of the ICF, experts have developed specific comprehensive ICF core sets [3], that are short lists of ICF categories important for patients with a specific disease. The ICF core set for OA (OA core set), recently developed contains 55 categories [4].

Several instruments have been used to measure HRQoL or health status among patients with OA of the lower limbs [5, 6] and those undergoing total hip or knee replacement [7–12]. In OA studies, the Medical Outcomes Study—Short Form 36 (MOS-SF36) is frequently combined with the WOMAC [5] or the Lequesne index [13], which measure function and pain. However, specific aspects of HRQoL could be missed even with a combination of different scales. The OsteoArthritis Knee and Hip Quality Of Life (OAKHQOL) is the first specific HRQoL questionnaire developed for knee and hip OA [14].The aim of its development was to introduce elements of QoL that patients with hip and knee OA at various stages of severity report as affecting their daily lives and to capture specific aspects of HRQoL as expressed by patients.

We aimed to document the content of the OAKHQOL, specifically to map the OAKHQOL content to the ICF categories, and to compare the OAKHQOL to other health status instruments frequently used in OA in terms of the OA core set.


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 Conclusion
 Acknowledgements
 References
 
The OAKHQOL
The OAKHQOL is a self-administered questionnaire comprising 40 items divided into five dimensions—physical activity, mental health, pain, social support and social activities—and three additional independent items [14].

Oral responses were elicited from patients and health professionals in five different ways [15]. For all methods, the sole instruction given to interviewees was to report the impact of OA on their (or their patients) HRQoL, the difficulties they encountered because of OA and during which circumstances they had difficulties in daily life. No HRQoL definition or specific question relating to the ICF components was used prior to or during the interviews. Content analysis of the tape-recorded transcripts elucidated different facets of the functionalist approach to QoL and of the needs-based model and confirmed that patients expressed the impact of disease in terms of the needs they were unable to meet. During the item-selection step that combined psychometric properties and content assessment, the WHO definition of health and QoL was used and selection was based on item relevance to this concept. The process generated 80 items, of which 43 were retained after content and psychometric analysis [14].

The raw scores of the OAKHQOL are the mean of observed items of each dimension and are calculated only if at least half of the items within the considered dimension are answered. The normalized scores vary from 0 (worst) to 100 (best possible HRQoL).

The International Classification Of Functioning, Disability and Health
The ICF is a general health status framework that comprehensively represents the experience of patients. The ICF framework contains four components that interact: body functions and body structures, activities and participation, environmental factors and personal factors. In the model, problems in functioning are a consequence of the interaction of a health condition and environmental and personal factors.

The four components of ICF include categories that represent the units of the ICF classification. Within the hierarchical code system of the classification, the categories are designated by a letter: (b) body functions, (s) body structures, (d) activities and participation or (e) environmental factors, followed by a numerical code. The numerical code begins with the chapter number (one digit), followed by the second level (two digits) and the third and fourth levels (one digit each) of definition [2, 16].

The ICF classification provides four lists of categories to characterize body functions, body structures, activities and participation, and environmental factors. However, personal factors cannot be coded, and no distinction can be made between activities and participation because they share the same list and are thus coded with the same codes.

The ICF model defines three main health outcomes: impairment assessed by body functions and body structures categories, activity limitations and participation restrictions.

The ICF allows for considering two different perspectives (subject and external observer perspective), whereas the HRQoL reflects subject perspective. Actually, all the ICF components can reflect subject perception: satisfaction with health condition, body functions and structures, activities and participation, and environmental factors. In this way, ICF and QoL are closely connected.

ICF core set for OA
To facilitate the application of the ICF, experts have developed specific comprehensive ICF core sets [3] for reporting functioning and health, defined as ‘what to measure for assessment of functioning’ for a specific disease. ICF core sets are lists of ICF categories that include as few categories as possible to be practical, but as many as necessary to be sufficiently comprehensive to describe the typical spectrum of problems in functioning of patients with a specific condition. The OA core set, recently developed, contains 55 categories [4].

Linking the items of the OAKHQOL to the ICF
Each item of the OAKHQOL was linked to ICF categories according to published linking rules [17, 18]. Health professionals trained in the ICF are advised to identify all meaningful concepts within each item of the health status measure under consideration according to these linking rules. Each meaningful concept is linked to the most precise ICF category. If a single item encompasses different concepts, the information in each concept should be linked. If a concept is not explicitly named in the corresponding ICF category, the lower level of the ICF classification is linked. If the information provided by the meaningful concept is not sufficient to determine its precise category, the concept is assigned ‘not definable’ (nd). A concept can be coded as ‘personal factors’ (pf). If a concept is not covered by the ICF classification, it is assigned ‘not covered’ (nc).

Two rheumatologists (J.P. and A.-C.R.) independently linked the OAKHQOL concepts to the ICF. The degree of agreement between the two investigators was assessed by analysis of the proportion of agreement in ICF second-level categories. Disagreements were discussed and a consensus was obtained.

Other health status measures
We compared the OAKHQOL to the five most frequently used instruments in OA. Among the generic HRQoL instruments, the MOS-SF36 is available in many languages [19, 20]. It contains 36 items in eight dimensions: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health [19, 21]. The WOMAC is a three-dimensional index with five items related to pain, 17 to physical function and three to stiffness [5]. The Lequesne index is also a function scale comprising 10 items assessing pain intensity, walking ability and physical function [13]. The short form of the Arthritis Impact Measurement Scales (AIMS2-SF) [22–25] measures five domains of health: physical function divided into upper and lower body limitations, social function, symptoms and affect. The HAQ is a questionnaire measuring the ability to perform daily life activities: dressing, arising, eating, walking, hygiene, reaching, gripping and other activities [26, 27].

Comparison of OAKHQOL and health status instruments using the OA core set
To focus the analysis on ICF categories especially pertinent to OA, we compared the OAKHQOL with the other health status instruments in terms of the OA core set instead of the whole ICF classification.

The WOMAC, Lequesne index, AIMS2-SF, HAQ and MOS-SF36 have already been linked to the ICF [1, 17, 28–31], and we used the published results for comparison with the OAKHQOL. However, several discrepancies were found in the reported articles, and some of the linkage rules have recently been updated [18]. After we checked the above-sited published results, we made a few modifications to the published linking results. As an example, in the WOMAC index, we linked the item ‘light domestic duties’ to the category ‘doing housework’ rather than to the category ‘domestic life unspecified.’

Since the categories of the OA core set were at the second level, we moved all third- and fourth-level ICF categories that were linked to the different instruments, to the second level.

For each instrument, we analysed the number of categories linked, the mean number of concepts per item and the mean number of concepts per OA core set category.

For the Lequesne index and the HAQ, several queries about aids or devices (e.g. use of a cane) are not considered to be items but, rather, serve to weight the scores. However, the queries were considered as items in terms of estimating the mean number of concepts per item.


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 Conclusion
 Acknowledgements
 References
 
Inter-observer reliability
The two physicians linking the ICF categories to the concepts contained in the 43 items of the OAKHQOL were in agreement with 83% of the second-level categories. Disagreements concerned five concepts involving activity/participation categories and three body function categories.

Linking the OAKHQOL to the ICF
Linking to the ICF whole classification
The 43 items of the OAKHQOL encompass 51 concepts linked to 27 second-level ICF categories: 16 categories of activities and participation, 5 body functions and 6 environmental factors. Nine other concepts are linked to four chapters (or subchapters) of the ICF. Two concepts are coded ‘nc’, three are personal factors and two are ‘nd’ (one referred to disability and the other to side-effects of medication) (Table 1).


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  		TABLE 1. Items of the OAKHQOL and the corresponding ICF categories

 
Linking to the OA core set
The OAKHQOL covered 20 categories of the current version of the OA core set and three ICF chapters. The six ICF body structures categories are not represented in any of the instruments and the two categories related to the upper arm are not appropriate to lower-limb OA. Only 3 of 19 ICF activities and participation categories are not addressed in the OAKHQOL. Among body functions categories, several concepts describe sleep, pain and emotional function categories (Table 2). The ICF environmental factors covered by the OAKHQOL include medication, products for personal mobility, support and relationships, and attitudes (Table 2).


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  		TABLE 2. Frequency with which the ICF OA core set categories were addressed in OAKHQOL and five other health status instruments

 
Conversely, several categories covered by the OAKHQOL are not included in the OA core set, although they are identified in other parts of the whole ICF (Table 1): experience of self, temperament and personality, carrying out daily routine, moving around using equipment, caring for body parts, family relationships, and acquaintances, peers, colleagues, neighbours and community support.

Comparison of the content of the OAKHQOL with other instruments in terms of the OA core set
The OAKHQOL and AIMS2-SF most comprehensively represent the OA core set. Indeed, 20 categories (plus three chapters) and 16 categories (plus one chapter) of the OA core set are covered by the OAKHQOL and the AIMS2-SF, respectively. Fewer than 14 ICF categories are addressed in the other instruments.

All instruments address pain, but only the OAKHQOL and AIMS2-SF address emotional and sleep functions. The MOS-SF36 addresses emotional function comprehensively but not sleep. The WOMAC, HAQ and AIMS2-SF but not OAKHQOL address stiffness. However, one item of the OAKHQOL is closely related to OA stiffness: ‘I have difficulty getting going again after staying in the same position for a long time.’ As well, the item related to stiffness in the AIMS2-SF is not really relevant for patients with OA because the length of time specified is too long (more than an hour).

The different instruments cover a broad range of ICF activity and participation categories.

Two items of the OAKHQOL are linked to ICF chapters (two chapters and one subchapter) and not categories. The item related to work is linked to a subchapter ‘Work and employment’ because it is quite general, but the same concept has been linked to the category ‘remunerative employment’ in a publication about mapping the ICF to the MOS-SF12 [18] or to ‘work and employment, other specified and unspecified’ in a paper mapping the ICF to the MOS-SF36 [17]. In the AIMS2-SF, the item related to work is more precise because it explicitly references remunerated work. Items referring to participation in social life are also more general in the OAKHQOL and are linked at a chapter level but are more precise in the AIMS2-SF and MOS-SF36.

Items linked to OA core set environmental factors categories are present only in the OAKHQOL, AIMS2-SF and HAQ. The HAQ is appropriate for required details on ‘products and technology for personal use or mobility’ categories. The AIMS2-SF and OAKHQOL are less precise on these categories but include items linked to the ICF ‘Support and relationships’ chapter.

A few categories represented in these five instruments were not found in the OA core set: fine hand use, carrying out daily routine, caring for body parts, using communication devices, preparing meals, school education, and religion and spirituality. The category d230 ‘Carrying out daily routine’ found in the OAKHQOL is also linked to an item of the SF36 and the category ‘d520 Caring for body parts’ is linked to an item of the HAQ. The other categories absent from the OA core set are not linked to items of the five questionnaires studied here but are part of other questionnaires: for example, b180 ‘Experience of self and time functions’ is in the WHOQOL and d760 ‘Family relationships’ in the EQ5D.

The mean number of concepts per item linked to the ICF and the mean number of concepts per OA core set category are displayed in Table 3.


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  		TABLE 3. Frequencies of items, concepts and ICF categories in the OAKHQOL instrument and other health status instruments

 

   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
Conclusion
 Acknowledgements
 References
 
Comparison of the content of health status instruments using the ICF as an independent reference framework illustrates that the various available instruments cover different categories with different levels of precision within a similar category.

The instruments we compared were not purported to measure similar health components and their conceptual frameworks were not the same. This may explain in part the observed differences. The MOS-SF36 is a generic HRQoL questionnaire, the AIMS2-SF is a specific HRQoL questionnaire used in different forms of arthritis, the OAKHQOL is a specific HRQoL questionnaire for OA of the lower-limb, the HAQ assesses functional ability in different forms of arthritis, and the WOMAC and Lequesne questionnaires assess pain and physical function for patients with lower limb OA.

The OAKHQOL, among the health status instruments studied, covered the highest number of categories of the OA core set. As the OA core set represents the minimal standard for reporting functioning and health in OA, a good coverage of its different categories is important. Such lists of ICF categories can serve to rate patients included in a clinical study with OA or to guide multidisciplinary assessments in patients with OA [4]. Moreover, the number of OAKHQOL concepts per ICF category was high (more than five) for emotional function, pain and support and relationships categories, which suggests that the OAKHQOL can describe in detail these areas that are especially relevant for patients with OA.

It is interesting to note that only four instruments cover the OA core set environmental factors, which are important determinants of HRQoL and participation. The HAQ is particularly detailed for products for personal use or mobility categories, whereas the OAKHQOL precisely covers the ‘Support and relationships’ chapter.

Besides the ICF pain and physical function categories, some categories important in OA were included in the OAKHQOL. Although emotional distress was not selected in the core set of outcome measures for OA developed by the OsteoArthritis Research Society International (OMERACT-OARSI) [32], the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) recommends including an assessment of emotional functioning [33]. Moreover, emotional functioning is often altered in patients with OA [34–37].

Components of social support [38, 39] are associated with HRQoL in OA. Greater social support is associated with higher physical functioning, mental health, social functioning and vitality [40, 41]. Only the AIMS2-SF and OAKHQOL include social support among their items. In the OAKHQOL, three social support items explore the satisfaction perceived or adequacy of support, and one item explores the availability of support or transactions.

Sleep is covered in the OAKHQOL and AIMS2-SF questionnaires. It is an important concern of patients, is often disturbed in OA and is a responsive outcome in clinical trials [8, 42, 43].

Body image, addressed in one item of the OAKHQOL, is also altered in OA. Indeed, compared with RA patients, patients with OA report a greater perceived deterioration of body image, with a more severe level of perceived disadvantage [44].

A few ICF categories linked to the OAKHQOL are not in the OA core set even though they were considered important by the patients: body image, carrying out daily routine, caring for body parts and using communication devices.

Such content differences are essential to consider for planning and reporting an investigation and before selecting one or a few health status instruments. The decision should be performed based on the targets and objectives of the intervention or study. For example, for a clinical trial of a short period of time, social support might not be especially relevant to address and measure. On the contrary, to comprehensively describe health status and functioning of patients with OA, instruments addressing specific issues such as sleep, social support or body image are more appropriate. In OA, pain and physical activity dimensions are usually more responsive but mental health, sleep and social participation are valuable for patients and should also be taken into account. Relying only on functional measures would overlook the diversity of self-perceived patient outcomes that are important to them and critical to determine the efficacy of a treatment and the health care system resources utilization. As recommended, a generic instrument is necessary to compare patients’ health status to normative data or other diseases, but based on their content relative to OA core set coverage, the OAKHQOL or the AIMS2-SF are the most comprehensive specific instruments to assess clinical outcome. To study determinants of participation, environmental factors are important and only the OAKHQOL or the AIMS2-SF contain several items on social support. In short-term clinical trials, when the effect size is expected to be small, pain and physical activity dimensions can be sufficient as other dimensions are less responsive and may need longer time to respond.

One can discuss the choice of the OA core set as a reference. Indeed, this first version still needs to be validated from the perspective of different professions, the perspective of patients and in different clinical settings. However, only a few categories of the different instruments were not part of the OA core set, all the instruments have been mapped to the whole ICF and the understanding of the results is facilitated. Moreover, the ICF is a general health status framework that comprehensively represents the experience of patients and thus is a valuable external reference to compare health status measurement instruments, even if concepts and perspectives are different.

Finally, it is important to remember that if the coverage of the OA core set is an important issue to consider, the choice of one or several questionnaires also depends on other psychometric properties of the instruments and on the objectives of the measure. At the time of the choice of a measure, classic approaches of construct validity remain important and content comparison is only one aspect of the entire validation.


   Conclusion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conclusion
Acknowledgements
 References
 
Comparison of the content of health status instruments used in OA illustrates that the various available instruments cover different ICF categories with different levels of precision. Such content differences are essential to consider for planning and reporting an investigation.

The content of the OAKHQOL maps well to the ICF, a general health status framework based on the patient experience that provides a scientific basis for understanding health states and their consequences and determinants. Compared with the five health status instruments commonly used in OA, the OAKHQOL covers the highest number of OA core set categories of the ICF. The OAKHQOL encompasses broad aspects of functioning, including some aspects of participation, and comprehensively addresses themes pertinent to patients with OA.

Formula


   Acknowledgements
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conclusion
 Acknowledgements
References
 
This study was conducted with the support of the Clinical Epidemiology Center-Institut National en Santé Et Recherche Médicale (CIC-EC-INSERM) CIE6, the French Ministry of Health and the University Hospital of Nancy.

Disclosure statement: The authors have declared no conflicts of interest.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conclusion
 Acknowledgements
 References
 

  1. Cieza A, Stucki G. Content comparison of health-related quality of life (HRQOL) instruments based on the International Classification of Functioning, Disability And Health (ICF). Qual Life Res (2005) 14:1225–37.[CrossRef][Web of Science][Medline]
  2. World Health Organization. International Classification of Functioning, Disability And Health: ICF. (2002) (4 January 2008, date last accessed). http://www3.who.int/icf/icftemplate.cfm.
  3. Cieza A, Ewert T, Ustun TB, et al. Development of ICF core sets for patients with chronic conditions. J Rehabil Med (2004) 44((Suppl)):9–11.[Medline]
  4. Dreinhofer K, Stucki G, Ewert T, et al. ICF Core Sets for osteoarthritis. J Rehabil Med (2004) 44((Suppl)):75–80.[Medline]
  5. Bellamy N, Buchanan WW, Goldsmith CH, Campbell J, Stitt LW. Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol (1988) 15:1833–40.[Web of Science][Medline]
  6. Pouchot J, Coste J, Guillemin F. Impact of osteoarthritis on quality of life. In: Osteoarthritis, clinical and experimental aspects—Reginster JY, Pelletier JP, Martel-Pelletier J, Henrotin Y, eds. (1999) Berlin: Springer. 331–55.
  7. Ethgen O, Bruyere O, Richy F, Dardennes C, Reginster JY. Health-related quality of life in total hip and total knee arthroplasty. A qualitative and systematic review of the literature. J Bone Joint Surg Am (2004) 86:963–74.[Abstract/Free Full Text]
  8. Fitzgerald JD, Orav EJ, Lee TH, et al. Patient quality of life during the 12 months following joint replacement surgery. Arthritis Rheum (2004) 51:100–9.[CrossRef][Web of Science][Medline]
  9. Hawker G, Melfi C, Paul J, Green R, Bombardier C. Comparison of a generic (SF-36) and a disease specific (WOMAC) (Western Ontario and McMaster Universities Osteoarthritis Index) instrument in the measurement of outcomes after knee replacement surgery. J Rheumatol (1995) 22:1193–6.[Web of Science][Medline]
  10. Nilsdotter AK, Petersson IF, Roos EM, Lohmander LS. Predictors of patient relevant outcome after total hip replacement for osteoarthritis: a prospective study. Ann Rheum Dis (2003) 62:923–30.[Abstract/Free Full Text]
  11. Sharma L, Sinacore J, Daugherty C, et al. Prognostic factors for functional outcome of total knee replacement: a prospective study. J Gerontol A Biol Sci Med Sci (1996) 51:152–7.
  12. Fortin PR, Penrod JR, Clarke AE, et al. Timing of total joint replacement affects clinical outcomes among patients with osteoarthritis of the hip or knee. Arthritis Rheum (2002) 46:3327–30.[CrossRef][Web of Science][Medline]
  13. Lequesne MG, Mery C, Samson M, Gerard P. Indexes of severity for osteoarthritis of the hip and knee. Validation – value in comparison with other assessment tests. Scand J Rheumatol Suppl (1987) 65:85–9.[Medline]
  14. Rat AC, Coste J, Pouchot J, et al. OAKHQOL: a new instrument to measure quality of life in knee and hip osteoarthritis. J Clin Epidemiol (2005) 58:47–55.[CrossRef][Web of Science][Medline]
  15. Rat AC, Pouchot J, Guillemin F, et al. Content of quality-of-life instruments is affected by item-generation methods. Int J Qual Health Care (2007) 19:390–8.[Abstract/Free Full Text]
  16. Organisation Mondiale de la Santé. Classification Internationale du Fonctionnement, du Handicap et de la Santé: CIF (2001) Genève: OMS.
  17. Cieza A, Brockow T, Ewert T, et al. Linking health-status measurements to the International Classification of Functioning, Disability and Health. J Rehabil Med (2002) 34:205–10.[CrossRef][Web of Science][Medline]
  18. Cieza A, Geyh S, Chatterji S, et al. ICF linking rules: an update based on lessons learned. J Rehabil Med (2005) 37:212–8.[CrossRef][Web of Science][Medline]
  19. Leplege A, Ecosse E, Verdier A, Perneger TV. The French SF-36 Health Survey: translation, cultural adaptation and preliminary psychometric evaluation. J Clin Epidemiol (1998) 51:1013–23.[CrossRef][Web of Science][Medline]
  20. McHorney CA, Ware JE Jr, Raczek AE. The MOS 36-Item short-form health survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Med Care (1993) 31:247–63.[Web of Science][Medline]
  21. Ware JE Jr, Gandek B. Overview of the SF-36 Health Survey and the International Quality of Life Assessment (IQOLA) project. J Clin Epidemiol (1998) 51:903–12.[CrossRef][Web of Science][Medline]
  22. Meenan RF, Mason JH, Anderson JJ, Guccione AA, Kazis LE. AIMS2. The content and properties of a revised and expanded arthritis impact measurement scales health status questionnaire. Arthritis Rheum (1992) 35:1–10.[Web of Science][Medline]
  23. Ren XS, Kazis L, Meenan RF. Short-form arthritis impact measurement scales 2: tests of reliability and validity among patients with osteoarthritis. Arthritis Care Res (1999) 12:163–71.[CrossRef][Web of Science][Medline]
  24. Pouchot J, Guillemin F, Coste J, Bregeon C, Sany J. Validity, reliability, and sensitivity to change of a French version of the arthritis impact measurement scales 2 (AIMS2) in patients with rheumatoid arthritis treated with methotrexate. J Rheumatol (1996) 23:52–60.[Web of Science][Medline]
  25. Guillemin F, Coste J, Pouchot J, et al. The AIMS2-SF: a short form of the arthritis impact measurement scales 2. French Quality Of Life in Rheumatology Group. Arthritis Rheum (1997) 40:1267–74.[Web of Science][Medline]
  26. Fries JF, Spitz P, Kraines RG, Holman HR. Measurement of patient outcome in arthritis. Arthritis Rheum (1980) 23:137–45.[Web of Science][Medline]
  27. Guillemin F, Briancon S, Pourel J. Validity and discriminant ability of the HAQ functional index in early rheumatoid arthritis. Disabil Rehabil (1992) 14:71–7.[Medline]
  28. Stucki G, Cieza A. The International Classification of Functioning, Disability and Health (ICF) core sets for rheumatoid arthritis: a way to specify functioning. Ann Rheum Dis (2004) 63(Suppl. 2):ii40–5.[Abstract/Free Full Text]
  29. Weigl M, Cieza A, Harder M, et al. Linking osteoarthritis-specific health-status measures to the International Classification of Functioning, Disability, and Health (ICF). Osteoarthritis Cartilage (2003) 11:519–23.[CrossRef][Web of Science][Medline]
  30. Sigl T, Cieza A, van der Heijde D, Stucki G. ICF based comparison of disease specific instruments measuring physical functional ability in ankylosing spondylitis. Ann Rheum Dis (2005) 64:1576–81.[Abstract/Free Full Text]
  31. Stamm T, Geyh S, Cieza A, et al. Measuring functioning in patients with hand osteoarthritis—content comparison of questionnaires based on the International Classification Of Functioning, Disability And Health (ICF). Rheumatology (2006) 45:1534–41.[Abstract/Free Full Text]
  32. Pham T, van der Heijde D, Altman RD, et al. OMERACT-OARSI initiative: Osteoarthritis Research Society International set of responder criteria for osteoarthritis clinical trials revisited. Osteoarthritis Cartilage (2004) 12:389–99.[CrossRef][Web of Science][Medline]
  33. Turk DC, Dworkin RH, Allen RR, et al. Core outcome domains for chronic pain clinical trials: IMMPACT recommendations. Pain (2003) 106:337–45.[CrossRef][Web of Science][Medline]
  34. Xie F, Li SC, Thumboo J. Do health-related quality-of-life domains and items in knee and hip osteoarthritis vary in importance across social-cultural contexts? A qualitative systematic literature review. Semin Arthritis Rheum (2005) 34:793–804.[CrossRef][Web of Science][Medline]
  35. Xie F, Li SC, Fong KY, et al. What health domains and items are important to patients with knee osteoarthritis? A focus group study in a multiethnic urban Asian population. Osteoarthritis Cartilage (2006) 14:224–30.[CrossRef][Web of Science][Medline]
  36. de Bock GH, Kaptein AA, Touw-Otten F, Mulder JD. Health-related quality of life in patients with osteoarthritis in a family practice setting. Arthritis Care Res (1995) 8:88–93.[Web of Science][Medline]
  37. Dexter P, Brandt K. Distribution and predictors of depressive symptoms in osteoarthritis. J Rheumatol (1994) 21:279–86.[Web of Science][Medline]
  38. Doeglas D, Suurmeijer T, Briancon S, et al. An international study on measuring social support: interactions and satisfaction. Soc Sci Med (1996) 43:1389–97.[CrossRef][Web of Science][Medline]
  39. Suurmeijer TP, Doeglas DM, Briancon S, et al. The measurement of social support in the ‘European Research on Incapacitating Diseases and Social Support’: the development of the Social Support Questionnaire for Transactions (SSQT). Soc Sci Med (1995) 40:1221–9.[CrossRef][Web of Science][Medline]
  40. Ethgen O, Vanparijs P, Delhalle S, et al. Social support and health-related quality of life in hip and knee osteoarthritis. Qual Life Res (2004) 13:321–30.[CrossRef][Web of Science][Medline]
  41. Sharma L, Cahue S, Song J, et al. Physical functioning over three years in knee osteoarthritis: role of psychosocial, local mechanical, and neuromuscular factors. Arthritis Rheum (2003) 48:3359–70.[CrossRef][Web of Science][Medline]
  42. Fielden JM, Gander PH, Horne JG, et al. An assessment of sleep disturbance in patients before and after total hip arthroplasty. J Arthroplasty (2003) 18:371–6.[CrossRef][Web of Science][Medline]
  43. Jordan JM, Bernard SL, Callahan LF, et al. Self-reported arthritis-related disruptions in sleep and daily life and the use of medical, complementary, and self-care strategies for arthritis: the National Survey of Self-Care and Aging. Arch Fam Med (2000) 9:143–9.[Abstract/Free Full Text]
  44. Carr AJ. Beyond disability: measuring the social and personal consequences of osteoarthritis. Osteoarthritis Cartilage (1999) 7:230–8.[CrossRef][Web of Science][Medline]
Submitted 11 January 2008; revised version accepted 25 July 2008.
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A. BOONEN, G. STUCKI, W. MAKSYMOWYCH, A. C. RAT, R. ESCORPIZO, M. BOERS, and the OMERACT-ICF Reference Group
The OMERACT-ICF Reference Group: Integrating the ICF into the OMERACT Process: Opportunities and Challenges
J Rheumatol, September 1, 2009; 36(9): 2057 - 2060.
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