Health-related quality of life in older adults with symptomatic hip and knee osteoarthritis: a comparison with matched healthy controls

Abstract

Health-related quality of life (HRQOL) assessment is receiving increasing attention as an outcome measure in osteoarthritis (OA). The aims of this study were to compare HRQOL among older adults aged 55 to 78 years with hip and/or knee OA with those without OA, and to assess the influence of selected variables (sex, body mass index, radiographic OA severity, educational level, comorbidities) on HRQOL. The generic Medical Outcome Study Short Form-36 item health status questionnaire (SF-36) was administered to a cohort of 264 OA patients (105 with hip OA alone, 108 with knee OA alone, and 51 with both hip and knee OA) and 112 healthy controls. Compared with the healthy controls, OA of the lower extremities has a detrimental effect on the eight-scale profile score, as well as on physical and mental summary measures of the SF-36. The most striking impact was seen in the physical measures "physical functioning", "physical role" and "pain" (p<0.0001). No statistically significant differences in SF-36 scores were found among the three groups of OA patients. The physical and mental summary scales of the SF-36 were closely correlated (p<0.0001). One hundred and forty-five patients (54.9%) reported at least one chronic coexisting disease. There was a significant inverse association with measures of comorbidity (number of comorbidities and comorbidity index score) and both physical and mental summary scores of the SF-36 questionnaire. In patients with OA of the knee alone (but not in hip OA alone or hip and knee OA), the SF-36 pain score was inversely correlated with years of formal education (p=0.016). In addition, the impact of hip and knee SF-36 dimensions was not influenced by the degree of radiographic severity. Older adults with OA of the lower extremities undergo a significant impact on multiple dimensions of HRQOL, compared with healthy controls. The use of a generic measure of HRQOL such as the SF-36, in studies of OA where comorbidity is common, should be useful in characterizing the global burden of this disease.