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Shared Decision-Making Tied to Better Outcomes in Patients With Knee Osteoarthritis

Key findings

  • Massachusetts General Hospital researchers conducted a secondary analysis of the randomized, multicenter DECIDE-OA trial that compared different decision-support tools for patients considering total joint replacement for hip or knee osteoarthritis
  • Patients who made well-informed, patient-centered (IPC) decisions experienced significantly greater improvements in overall quality of life than patients who made non-IPC decisions
  • Patients with knee osteoarthritis who made IPC decisions reported a larger improvement in Knee Injury and Osteoarthritis Outcome Score, higher satisfaction and less decision regret than those who did not
  • For patients with hip osteoarthritis, IPC decisions did not predict better Harris hip scores, higher satisfaction or less regret; the differences from patients with knee osteoarthritis might be due to the typically greater success of hip replacement
  • While IPC decisions led to greater improvements in quality of life, this study showed that surgeons are less likely to engage women in shared decision-making compared with men

Evidence-based guidelines in orthopedics recommend shared decision-making for the treatment of hip and knee osteoarthritis. The elements of shared decision-making are to inform patients about surgical and nonoperative options, listen to patient goals and concerns and tailor the recommendation to patient preferences.

Little research has examined whether shared decision-making predicts outcomes of total joint replacement. Karen Sepucha, PhD, director of the Health Decision Sciences Center at Massachusetts General Hospital, Hany S. Bedair, MD, chair of the Center for Hip & Knee Replacement in the Department of Orthopaedic Surgery, and colleagues investigated this issue by examining data from DECIDE-OA, a randomized, multicenter trial that compared different decision-support tools.

In The Journal of Bone and Joint Surgery, they report that, for patients with knee osteoarthritis, well-informed, patient-centered decisions predicted small improvements in outcomes, greater satisfaction and less regret. However, the same was not true for patients with hip osteoarthritis.

Study Methods

The team analyzed data on 845 patients with osteoarthritis (283 hip, 562 knee) who were recruited at three sites. All patients received a decision aid before visiting a surgeon.

Surgeons at each site, matched on patient volume and years in practice, were randomly assigned to an intervention arm or usual care. Those in the intervention arm received a report on patient responses to three items: the main goal for the visit; a list of three important activities patients were unable to perform because of symptoms; and treatment preference.

Shortly after the surgical consultation, each patient completed a joint-specific set of patient-reported outcome measures and either the Knee Osteoarthritis Decision Quality Instrument (DQI) or Hip Osteoarthritis DQI. The DQI surveys include five knowledge items and one item assessing treatment preference (surgical, nonsurgical or unsure). Six months post-visit (or six months postoperatively, for those who had surgery), patients completed the same set of patient-reported outcome measures.

Quality of Decision-making

Patients who scored ≥60% on the DQI knowledge items were considered well-informed. The researchers then compared the DQI treatment preference item with the treatment received. Patients who were well informed and received their preferred treatment were considered to have made informed, patient-centered (IPC) decisions.

68% of the sample (74% of patients with hip osteoarthritis and 66% of those with knee osteoarthritis) met the criteria for IPC decisions.

Women were significantly less likely than men to receive their preferred treatment, even though knowledge scores were similar by sex. In fact, 15% of women indicated a clear preference for surgery but did not undergo total joint replacement even though most were good surgical candidates. Studies of total knee replacement have documented that surgeons are less likely to engage women in shared decision-making compared with men.

Outcomes

After adjustment for type of treatment and other potential confounders, the following outcomes were present:

  • EuroQol-5 Dimension, a measure of general health status—more improvement with IPC than non-IPC decisions (adjusted mean difference, 0.04 points; P<0.001)
  • Knee Injury and Osteoarthritis Outcome Score—more improvement with IPC than non-IPC decisions (adjusted mean difference, 4.9 points; P=0.004)
  • Harris hip score—no significant difference between IPC and non-IPC decisions

Satisfaction and Decision Regret

Knee osteoporosis

  • Overall satisfaction—higher with IPC decisions (adjusted OR (aOR), 1.7; P=0.003)
  • Satisfaction with pain relief—better with IPC decisions (aOR, 2.1; P=0.002)
  • Decision regret—more likely to have none with IPC decisions (aOR, 2.3; P=0.003)

Hip osteoporosis

  • Overall satisfaction—IPC decisions were not a significant predictor
  • Satisfaction with pain relief—IPC decisions were not a significant predictor
  • Decision regret—more likely with IPC decisions

Interpreting the Findings

The IPC decision rate of 68% is more than twice the rate reported for usual care in other published studies. That suggests the use of a decision aid helps inform and engage patients who are considering total joint replacement.

These results support previous studies that show the "preference effect" may influence outcomes of total hip or knee replacement. Simply put, patients who had a strong preference for the treatment they received may experience better outcomes than those who did not prefer it.

Why the differences in results between hip and knee replacement? Both provide a high likelihood of nearly complete pain relief, but hip surgery tends to provide greater relief than knee surgery, and the recovery period is shorter and easier. Considering the success of hip replacement, there may be limited ability to document further improvement with shared decision-making.

68%
of patients who received a decision aid about hip or knee replacement later made a well-informed, patient-centered decision

1.7x
greater odds of overall satisfaction with treatment among patients with knee osteoarthritis who made a well-informed, patient-centered decision

2.1x
greater odds of satisfaction with pain relief among patients with knee osteoarthritis who made a well-informed, patient-centered decision

2.3x
greater odds of no decision regret among patients with knee osteoarthritis who made a well-informed, patient-centered decision

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