Predictors Of Undergoing Joint Replacement Surgery Among Patients With Severe Osteoarthritis

A progressive, destructive joint disease, osteoarthritis (OA) is a major cause of disability worldwide. Total joint arthroplasty (TJA) is a highly successful and cost-effective procedure for managing OA of the hip and knee. Despite this, analyses of hospital records show variations in the rates of TJA by region, gender, race, and socioeconomic status. While these studies tell us about who is undergoing hip and knee replacement surgery, what's missing is why--a comprehensive, rigorous examination of the predisposing factors affecting TJA rates.



Why do some arthritis sufferers agree to undergo TJA and others resist it? To examine the predictors of time to a first TJA, a team of Canadian researchers, affiliated with the University of Toronto and other research institutes, conducted a population-based study of 2,128 individuals ages 55 and over with disabling OA of the hip and/or knee. Their findings, featured in the October 2006 issue of Arthritis & Rheumatism (interscience.wiley/journal/arthritis), support the need for community-based education about arthritis treatments, including hip and knee replacement surgery.



This groundbreaking study focused on two regions of Ontario--one rural with high rates of TJA and one urban with low rates. It started in 1999 with an established sample of older citizens--1,158 from the country; 970 from the city--with severe hip and/or knee OA and no prior joint replacement. Researchers devoted 7 years to follow up, consisting of annual surveys and check-ups on disease progression, linked with hospital databases to determine whether patients had undergone hip or knee replacement surgery.



Among the study population, 73 percent were women, 96 percent were white, 31 percent were living alone, independently, and nearly 68 percent had a high school education or higher. At baseline, the mean age was 71.5 years and the mean WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) arthritis severity score was 41.1/100. At baseline, 48 percent of those surveyed had seen a physician in the past year for hip and/or knee problems, but only 20 percent were willing to consider TJA.



During the follow-up period, scores of disease severity, incidents of doctor visits, and willingness to consider TJA as a treatment option increased. By the culmination, nearly 24 percent of the study population underwent at least one TJA procedure. The rate of joint replacement surgery was almost equal in the two geographic regions--11.8 percent of rural patients and 12.1 percent of urban patients. Researchers evaluated the predictive value of other variables, using the tools of statistical analysis. The factor with the strongest influence over the length of time to the first TJA was an openness to surgery--the patient's willingness.
















To test the strength of this subjective factor and its relationship to other factors, the team calculated time to TJA excluding willingness. A higher education level was significantly correlated with follow through on hip or knee replacement. There was no independent association, however, with either income level or gender. Disease severity did have an impact on the time to TJA, but only among patients who expressed a preference for surgery. Among individuals with similar arthritis severity, the probability of undergoing a TJA was almost 4 times greater for those willing to consider the potential benefits of surgery than for those who were unsure about the process or unwilling.



This unique community-based study indicates the power of education to increase the willingness of arthritis sufferers to explore and choose the option of TJA, regardless of socioeconomic status or disability. "Our findings highlight the need for the development and implementation of strategies directed at the level of health care delivery," stresses the study's lead author, Dr.Gillian Hawker, "possibly through population education programs about arthritis and its treatment, and in particular about the indications for and expected outcomes of specific interventions like TJA." Yet, one critical factor this study does not address is the complex issue of access to elective surgery, specifically in the United States.







Article: "A Prospective Population-Based Study of the Predictors of Undergoing Total Joint Arthroplasty," Gillian A. Hawker, Jun Guan, Ruth Croxford, Peter C. Coyte, Richard H. Glazier, Bart J. Harvey, James G. Wright, Jack I. Williams, and Elizabeth M. Badley, Arthritis & Rheumatism, October 2006; (DOI: 10.1002/art.22146).



Contact: Amy Molnar


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