Original ArticleOAKHQOL: A new instrument to measure quality of life in knee and hip osteoarthritis
Introduction
Osteoarthritis (OA) is a chronic disease and a major cause of pain and disability. An estimated 7–11% of the populations of developed countries have symptomatic OA, and 27–44% have radiographic disease; the annual incidence in the United Kingdom is reported to be 3.1% [1], [2], [3]. As OA increases in prevalence with age, the growing proportion of elderly people in the populations of many countries will lead to it becoming an increasingly important global public health problem. OA already accounts for considerable expenditure by health care providers [4], [5], and the cost to OA patients themselves can be substantial [6]. Apart from its economic consequences, OA is a major cause of disability, quality of life impairment, and social dysfunction [6]. It should therefore be a high priority for health care professionals, researchers, and public health decision-makers.
There is a growing interest in using quality of life (QoL) assessment to help investigate the impact of new pharmaceutical products and other interventions. The US FDA guide for clinical development programs in OA recommends that efficacy endpoints include: a measure of pain, patient global assessment, and a self-administered questionnaire covering pain and function (McMaster Western Ontario questionnaire [WOMAC] or Lequesne's index) [7], [8]. QoL instruments are particularly valuable in patient global assessment because of their ability to capture more than just pain and disability [9].
Several tools have been used to measure health-related quality of life (HRQoL) among patients with OA of the lower limbs [7], [10] and those undergoing total hip or knee surgery [11], [12], [13], [14], [15], [16]. The Medical Outcomes Study Short-Form 36 (SF36) has been widely applied but, as a generic instrument, tends to be less responsive than specific instruments [17], particularly in the context of a medical or rehabilitation intervention rather than joint replacement. Comparisons of the SF36 with a disease-specific instrument (WOMAC) in patients undergoing knee replacement surgery report that they measure different aspects of health and should probably be used together [12], [13]. However, no specific HRQoL instrument has been developed for patients with OA of the lower limb. WOMAC [7] and Lequesne's index [8] measure pain and functional disability but do not take other domains of QoL into account. The Arthritis Impact Measurement Scales (AIMS2) tool [18] and its short form AIMS2-SF [19] have been considered for use in OA but have a limited usefulness among patients with a high prevalence of lower limb disability [20].
There is a clear need for a disease-specific instrument with good content, construct validity, and responsiveness in assessing the QoL of patients with lower limb OA. We hypothesized that specific aspects of QoL are encountered by patients with knee and hip OA. Apart from affecting physical activities, knee or hip OA may also have an impact on mental health in terms of anxiety and depression, on sleep, on sexuality, and on social functioning [21], [22]. Some specific aspects like social support have also already been demonstrated to be of importance in this pathology [23]. The combination of the SF36 with the WOMAC or the Lequesne index may thus not capture these specific aspects of HRQoL expressed by patients with knee and hip OA. The knee and hip osteoarthritis quality of life questionnaire (OAKHQOL) should be more able to apprehend aspects specifically appropriate to knee and hip OA patients.
Our aim was to develop a new instrument (OAKHQOL) with the ability to capture a patient's perception of his or her disease and with the psychometric properties required for use in clinical trials and observational studies. As the construction process of a QoL instrument has a major influence on its content and construct validity, OAKHQOL was developed a priori. The present article reports its conception, development, and early testing.
Section snippets
Materials and methods
OAKHQOL was developed in three stages: first, a qualitative stage to define the concept and content of the instrument, elicit verbatim remarks, build categories, and generate items; second, a quantitative stage to examine the properties of items, and determine the dimensional and factorial structure of the finished questionnaire; and third, preliminary psychometric analysis (item-scale correlations, construct validity, reliability).
Qualitative stage
One hundred twenty-eight patients and 32 health professionals participated in this stage. The initial analysis of interview transcripts identified 119 relevant items, of which, 83 were pertinent and related to QoL. The first version of the OAKHQOL 1.0 was a self-administered questionnaire of 46 items reported in terms of their frequency and intensity.
Sample characteristics
Of 263 patients recruited in outpatient clinics, 139 were being treated medically, 97 were scheduled for surgery, and 27 had undergone total
Discussion
The OAKHQOL is the first specific knee and hip OA quality of life instrument. Its development followed an a priori structured strategy to ensure content validity. It meets psychometric requirements for validity and reliability.
The intention when developing OAKHQOL was to introduce elements of QoL that patients with hip and knee OA at various stages of severity report as affecting their daily lives. Within the framework provided by WHO, the a priori strategy adopted has allowed for the
Acknowledgments
The authors wish to thank M. Alfonsi, F. Arnould, X. Ayral, P. Bouillot, I. Cahitte, I. Chary-Valckenaere, P. Chaspoux, C. Cuny, J.P. Delagoutte, P. Fener, H. Gaudin, M.F. Gérard, F. Goupy Le Maitre, J. P. Gros, D. Hannouche, E. Hiraux, N. Jeanson, J.M. Lardry, D. Loeuille, D. Mainard, D. Nebout, G. Osnowycz, H. Ouakil, S. Perrot, S. Poiraudeau, J. Pourel, P. Prost, P. Rabany, M. Rousseau, Dr. Thomas, F Touzard, G. Vançon, L. Vastel, and J.P. Voilquin. This study was conducted with the support
References (51)
- et al.
Outcome after total hip arthroplasty. Comparison of a traditional disease-specific and a quality-of-life measurement of outcome
J Arthroplasty
(1997) - et al.
An assessment of sleep disturbance in patients before and after total hip arthroplasty
J Arthroplasty
(2003) - et al.
Assessment of the impact of disease on the individual
Best Pract Res Clin Rheumatol
(2003) - et al.
Methods for testing data quality, scaling assumptions, and reliability: the IQOLA Project approach. International Quality of Life Assessment
J Clin Epidemiol
(1998) - et al.
A new measure of quality of life in depression: testing the reliability and construct validity of the QLDS
Health Policy
(1992) - et al.
Methodological approaches to shortening composite measurement scales
J Clin Epidemiol
(1997) - et al.
Overview of the SF-36 Health Survey and the International Quality of Life Assessment (IQOLA) Project
J Clin Epidemiol
(1998) - et al.
The French SF-36 Health Survey: translation, cultural adaptation, and preliminary psychometric evaluation
J Clin Epidemiol
(1998) - et al.
Reliability, validity, and sensitivity to change of the Cochin hand functional disability scale in hand osteoarthritis
Osteoarthritis Cartilage
(2001) - et al.
Cross-cultural adaptation of health-related quality of life measures: literature review and proposed guidelines
J Clin Epidemiol
(1993)
The incidence and natural history of knee osteoarthritis in the elderly. The Framingham Osteoarthritis Study
Arthritis Rheum
An update on the epidemiology of knee and hip osteoarthritis with a view to prevention
Arthritis Rheum
Incidence and risk factors for radiographic knee osteoarthritis in middle-aged women: the Chingford Study
Arthritis Rheum
Direct medical costs unique to people with arthritis
J Rheumatol
Indirect and nonmedical costs among people with rheumatoid arthritis and osteoarthritis compared with nonarthritic controls
J Rheumatol
Living with osteoarthritis: patient expenditures, health status, and social impact
Arthritis Rheum
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
Indexes of severity for osteoarthritis of the hip and knee. Validation–value in comparison with other assessment tests
Scand J Rheumatol Suppl
Apport des instruments de mesure d'incapacité fonctionnelle et de qualité de vie dans l'arthrose [Contribution of functional disability and quality of life measures to the evaluation of patients with osteoarthritis.]
Rev Rhum
Evaluation à un an de la qualité de vie après arthroplastie totale de hanche et de genou
[Quality of life assessment one year after total hip or knee arthroplasty.] Rev Chir Orthop Reparatrice Appar Mot
Comparison of a generic and a disease-specific measure of pain and physical function after knee replacement surgery
Med Care
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
Health-related quality of life after elective surgery: measurement of longitudinal changes
J Gen Intern Med
Patient outcomes after knee replacement
Clin Orthop
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