Impact of osteoarthritis: results of a nationwide survey of 10,000 patients consulting for OA

Abstract

The clinical burden of osteoarthritis (OA) is difficult to assess because of the substantial variability between patients.

Objective.– Evaluate the human consequences of OA in patients.

Methods.– In 2000, a nationwide survey was conducted among a sample of more than 5000 physicians (90.3% general practitioners and 9.7% rheumatologists), representative of French physicians. Each recruited the first two patients consulting for hip, knee, or hand OA after the survey began. The functional limitation rates were compared with those for age- and sex-matched controls obtained from the 1999 population-based national survey on disability (HID survey).

Results.– Clinical and demographic information was obtained for 10,412 OA patients (mean-age 66.2 years, sex ratio F:M 1.96). The OA diagnosis was based on both clinical and radiographic findings for 84.5%. More than 80% of all patients reported limitations in their activities of daily living, either for basic tasks, leisure activities, or work. OA patients were substantially more limited than controls: the standardised limitation rate ratios (SLRR) were 6.0 (95% confidence interval: 5.9:6.1) for mobility outside the home, 2.1 (2.0:2.1) for house cleaning, 1.6 (1.5:1.8) for dressing oneself, and 1.6 (1.5:1.8) for sports. Of the 17.6% of OA patients and 17.5% of the controls still working, 64.4% and 14.3%, respectively, were limited in their job duties, for a SLRR of 4.5 (4.3:4.7).

Conclusion.– This study shows that OA-related disability has a significant impact on the retired as well as on those still involved in the labour market.

Introduction

Osteoarthritis (OA), caused by cartilage and subchondral bone degeneration, is the most common of the joint diseases. Its prevalence increases with age. Because it is heterogeneous and lacks any consensual definition, its epidemiology is complex [1], [2]. Prevalence estimates vary widely, since some authors focus on radiological OA and others on symptomatic disease [3]. Up to half the adult population may have signs of OA on systematic radiography [4], [5], but only 40% of those with Kellgren and Lawrence stage II OA and 60% of those with stage III OA appear to have clinical symptoms of the disease [6], [7]. Moreover, the prevalence of symptomatic OA varies widely according to age and the joints involved: from 10% of those aged 40–49 years to 80% of those older than 70 years for hand OA; from 2% to 10% of those 55 or older for hip OA; from 15% of those older than 45 years to 40% of those older than 75 for knee OA [6], [8], [9].

Behind these statistics, the human impact of OA at a population level is difficult to estimate. Although often considered a non-serious disease, it has a major impact on patients and their families. In a British survey, more than 90% of OA patients reported functional limitations in their activities of daily living, a percentage very close to that observed in a population of patients with rheumatoid arthritis [10]. Because of the disability that it can induce, OA generates substantial costs to society, especially with respect to the elderly, who are the most likely to become dependent and socially isolated when affected by such a disease [11], [12]. At the population level, the economic burden of OA has been evaluated at seven times that of rheumatoid arthritis [13].

The objective of this study was to gather information about the medical and human reality of OA in a large sample of patients, identified during a nationwide survey of more than 5,000 physicians. We addressed three principal questions: Who seeks care for OA? What are the consequences of this degenerative joint disease in their daily lives? Are OA patients substantially more limited than age- and sex-matched controls? To answer the latter question, we compared the functional limitation rates observed in the sample of OA patients with those obtained from a national survey of a representative sample of the French general population in 1999 [14].