If given a choice of arthritis treatments, for many older people a low risk of side effects is more important than effectiveness.

In a small study of 100 people with knee osteoarthritis who were asked to evaluate various treatment options, a pain-relieving cream was the most popular choice, even though it is less effective than other treatments, researchers report.

One caveat about the study is that participants were asked to select an arthritis treatment assuming that they would have to pay the full cost of the treatment.

“The results of this study underscore the importance of involving patients in treatment decisions for knee osteoarthritis, where most treatment options are associated with relatively modest benefits, but differ significantly in both potential risks and out-of-pocket costs,” a team led by Dr. Liana Fraenkel at Yale University School of Medicine in New Haven, Connecticut, report in the Archives of Internal Medicine.

There are a variety of ways to treat arthritis, including weight loss, muscle-strengthening exercises, prescription and non-prescription drugs, and surgery.

Some of the most commonly used drugs to treat knee arthritis include acetaminophen - the active ingredient in Tylenol and other over-the-counter pain relievers - as well as nonsteroidal anti-inflammatory drugs, or NSAIDs. This class of drugs includes over-the-counter pain relievers such as ibuprofen, aspirin and naproxen, as well the newer prescription drugs celecoxib (Celebrex) and rofecoxib (Vioxx).

Doctors often choose NSAIDs as the first-line therapy for knee arthritis, but there has been little research on what people with arthritis prefer, according to Fraenkel and her colleagues.

In the new study, participants were asked to decide which arthritis treatment they would choose assuming that they would have to pay the full cost of treatment. The researchers outlined the risks and benefits of each option.

When faced with having to pay the full cost of treatment, more than 40 percent of participants chose a topical cream containing capsaicin.

Capsaicin was even more popular than newer prescription NSAIDs, which are designed to minimize gastrointestinal side effects. Participants only preferred the newer NSAIDs when told that they would only have to pay a small copayment for treatment and that the drugs are three times more effective than capsaicin.

Older forms of NSAIDs, which are the most popularly recommended treatments for knee arthritis, were the least popular among people with arthritis.

Overall, concerns about the risk of common side effects and the risk of an ulcer had the greatest impact on people’s treatment choices. These concerns were more important than several other factors including chances of benefiting from the treatment, the time to achieve a benefit, and cost.

SOURCE: Archives of Internal Medicine, June 28, 2004.