VANCOUVER, British Columbia—The first study to ask patients with osteoarthritis (OA) of the hip or knee how much additional risk of drug-induced gastrointestinal, cardiovascular, or cerebrovascular complications they would tolerate for relief of OA pain reports that most will accept some additional risk and are more willing to accept greater risk of stomach bleeding than heart attack or stroke; risk tolerance was lowest in patients who already had other risk factors in the relevant area. Chris G. Richardson, PhD, and colleagues from the University of British Columbia also report that willingness to accept side effect risk is not significantly associated with the OA patient's level of pain. The study is reported in The Journal of Rheumatology.1

"Our study provides empirical support for the belief that many patients would accept this risk for pain relief if given the choice."—Chris G. Richardson, PhD.
"In one trial, 3.6% of patients taking rofecoxib (25 mg per day) experienced a serious thrombotic event compared to 2.0% in the placebo group. Our study provides empirical support for the belief that many patients would accept this risk for pain relief if given the choice, and highlights the need to explicitly consider patients' attitudes toward maximal acceptable risk increments when helping them arrive at informed choices among optional therapies," Dr. Richardson says.

Threshold techniques used to quantify acceptable risk for side effects

The  study included 196 patients for whom researchers used a set of threshold technique tasks to quantify patients' maximal acceptable risk for a measured condition. "Each task described 2 treatment options, their levels of pain relief, and the risks of side effects," Dr. Richardson explains. "The risk for the side effect under investigation was then systematically increased to reveal the maximal acceptable risk increment associated with the pain reduction." Their Western Ontario and McMaster (WOMAC) scores rated these patients as having moderately severe OA.

The maximal acceptable risk for stomach bleeding or heart attack/stroke was not affected by the patient's baseline pain level. However, there was a statistical significance at baseline of the patient's side effects level and accepted incremental risk of stomach bleeding and heart attack/stroke. Patients were, not surprisingly, also willing to accept greater risk of both kinds of side effects in exchange for the chance of greater pain relief (2 points vs 5 points on a 10-point pain scale).

Finally, the study showed that, for the same level of potential pain relief, patients were more willing to accept increased risk for stomach bleeding than for heart attack or stroke.

In summary, Dr. Richardson reports that:

  • 64.5% of patients would accept some additional risk of both stomach bleed and heart attack/stroke for a 2-point (20%) pain reduction
  • 72.6% would accept additional risk of both stomach bleed and heart attack/stroke for a 5-point (50%) pain reduction
  • 22.3% would not accept any increased risk in either type of adverse effect for a 2-point pain reduction, and
  • 14.7% would not accept any increased risk in either type of adverse effect for a 5-point pain reduction

"In other words, among those who would accept some additional risks, subjects' maximal acceptable risk increment for stomach bleed[ing] was roughly 4 times greater than their maximal acceptable risk increment for heart attack/stroke, in both the 2-point and 5-point pain reduction conditions," Dr. Richardson explains.

"We recommend that clinicians examine the risk attitude and treatment preferences of each patient on an individual basis when deciding on a treatment regimen," Dr. Richardson concludes.

Reference

1. Richardson CG, Chalmers A, Llewellyn-Thomas HA, et al. Pain relief in osteoarthritis: patients' willingness to risk medication-induced gastrointestinal, cardiovascular, and cerebrovascular complications. J Rheumatol. 2007;34:1569-1575.