Identifying the Need for Hip and Knee Arthroplasty – A Community Survey

Arthritis is the number one cause of disability in the population. Health care interventions designed to target modifiable determinants of arthritis disability can be expected to have an important effect on the health of Canadians. The most common type of arthritis is osteoarthritis (OA). There is no cure for OA. Thus, medical management of OA is directed towards pain relief and preserving and improving physical function. One intervention which has been shown to reduce OA-related disability is total joint replacement (TJR) surgery. For individuals with advanced hip and knee OA, in whom medical treatment has failed, total joint replacement has become the accepted treatment. Yet, despite its established efficacy, area variation exists in the rates of TJR use and predictors of disability are largely unknown.

In 1995, we began a large population-based study in Ontario called the Study of Arthritis in Your Community. The aim of this study was to assess the need and willingness to have total joint replacements (TJR) among people living with severe hip and/or knee arthritis. We were also interested in examining the appropriateness of the rates of TJR and the gender and socioeconomic differences in the provision of TJR surgery. We wanted to define the nature (patterns and types of joint involvement) and impact (self-reported disability and health care utilization) of arthritis and rheumatism in the population.

Methods

A screening questionnaire was mailed to the entire population of people aged 55 years and older in two Ontario communities to identify individuals with disabling hip/knee arthritis. We selected two communities where the current rates for TJR were known and shown to be disparate: Oxford County, a rural community in southwestern Ontario with a high rate of TJR and East York, an urban community in Toronto with a low rate of TJR.

From more than 28,000 participants, we identified 2,411 individuals with hip or knee joint problems. These individuals were asked additional questions to determine education, income, general health status, arthritis severity and TJR waiting list status. Good surgical patients were also asked about their willingness to have TJR. Individuals with the highest level of pain were considered to have the greatest potential need for TJR.

Results

Unmet Need for Joint Replacement

We documented potential unmet need for total joint replacement (TJR) in both regions. However, both the prevalence of severe hip/knee arthritis and willingness to have TJR were significantly greater in the high-rate area. Furthermore, for the first time, we documented a wide gap between potential need for a procedure (TJR), as defined from the point of view of surgical indication, and actual need, as defined from the point of view of the patient. Among individuals with potential TJR need, fewer than 15% were definitely willing to consider having this surgery. This research is important as it puts to rest a long-standing source of confusion in the surgical variation literature: the failure to distinguish clearly between two factors governing the need for surgery: the prevalence of illness, and the preferences of patients. Importantly, our findings suggest there may not be a “right rate” for discretionary procedures like TJR that can be applied across large geographic areas if both disease prevalence and patients’ preferences are considered.

  • Hawker GA, Wright JG, Coyte PC, Williams JI, Harvey B, Glazier R, Wilkins A, Badley EM. Determining the need for hip and knee arthroplasty – The role of clinical severity and patients’ preferences. Medical Care. 2001;39:1-11.

Gender and Socioeconomic Differences in Need for TJR

Need for TJR (i.e., severe hip/knee arthritis and no surgical contraindications) was more than three times greater in women than men, yet women were less likely to have had a TJR. Furthermore, those with need had less often discussed TJR with a physician and were less likely to be on a TJR waiting list. Disparity in need was also found by socioeconomic status (SES – education and income). Individuals with low SES were more likely to meet our criteria for need for TJR, yet less likely to be on a TJR waiting list. Men and women with low SES were equally likely to have unmet need for TJR, whereas among those with higher SES, women were more likely than men to have unmet need for surgery.

  • Hawker GA, Wright JG, Coyte PC, Williams JI, Harvey B, Glazier R, Badley EM. Differences between men and women in the use of total joint arthroplasty. New England Journal of Medicine. 2000; 342:1012-1022.

Willingness to Have Joint Replacement Surgery

Among our cohort with disabling hip/knee arthritis, willingness to consider TJR was independently associated with younger age, worse perceived arthritis severity (but not measured severity), fewer comorbidities, perceived indications for TJR and acceptability of associated surgical risks, especially risk of revision surgery, and the opinions and experiences of friends. Interestingly, participants significantly over-estimated the degree of joint pain and disability needed to warrant TJR. These misperceptions largely explained the low observed rates of willingness to consider TJR, and suggest a need for education at a population level. Furthermore, we documented significant gender and socioeconomic differences in TJR perceptions that warranted further attention.

  • Hawker GA, Wright JG, Badley EM, Coyte PC, for the Toronto Arthroplasty Health Services Research Consortium. Perceptions of, and willingness to consider, total joint arthroplasty in a population-based cohort of individuals with disabling hip and knee arthritis. Arthritis & Rheumatism 2004; 51(4) 635-641.

Summary

Overall, the findings of this research project shed new light on the interpretation of small area variations in health care utilization, and have led to a shift in research emphasis from area variation to disparity in access to care among people with OA. This research was heavily cited by the December 2003 NIH Consensus Panel on Total Knee Replacement, which called for research population-based studies to determine whether there are indeed disparities in utilization of knee replacement, and if so, why.

Investigators

Gillian Hawker (PI), Elizabeth Badley, Peter Coyte, Richard Glazier, Jack Williams, Jim Wright, Bart Harvey

Date

1995-1998

Grants

  • Identifying the Need for Hip and Knee Arthroplasty – A Community Survey.
    Investigators: G. Hawker (PI), E.M. Badley, P. Coyte, R. Glazier, J. Williams, J. Wright. Funding Organization Medical Research Council (1995-1997)
  • Individuals’ preferences for joint replacement surgery in assessing the need for hip and knee arthroplasty.
    Investigators: G. Hawker (PI), E.M. Badley, P. Coyte, R. Glazier, J. Williams, J. Wright. Funding Organization: PSI (1995-1996)
  • Assessing the unmet need for joint replacement.
    Investigators: G. Hawker (PI), J. Wright, E.M. Badley, P. Coyte, R. Glazier, J. Williams, B. Harvey. Funding Organization: Canadian Orthopaedic Foundation (Hip Hip Hooray) (1996-1997)
  • Validation of the use of patient self-report to estimate need for total joint replacement.
    Investigators: G. Hawker (PI), E.M. Badley, P. Coyte, R. Glazier, J. Williams, J. Wright. Funding Organization: Dean’s Fund, Faculty of Medicine, University of Toronto. (1996-1997)
  • Identifying the Need for Hip and Knee Arthroplasty – A community survey.
    Investigators: G. Hawker (PI), E.M. Badley, P. Coyte, R. Glazier, B. Harvey, J. Williams, J. Wright. Funding Organization: Medical Research Council (Renewal) (1997-1998)
  • Individuals’ preferences for joint replacement surgery in assessing the need for hip and knee arthroplasty.
    Investigators: G. Hawker (PI), J. Wright, E.M. Badley, P. Coyte, R. Glazier, J. Williams, B. Harvey. Funding Organization: The Arthritis Society of Canada. (1997-1998)