People diagnosed with knee osteoarthritis often start using pain relief medications on their own, without the advice of a health professional on the best treatment option, a new Canadian study suggests.

Osteoarthritis (OA) is the most common form of arthritis, and can contribute to disability and reduced quality of life when tasks such as climbing stairs can become difficult. About 4.3 million Americans over age 60 have symptoms of knee osteoarthritis, according to the U.S. Centers for Disease Control and Prevention.

'Most concerning was the greater number of participants who opted to first use NSAIDs prior to trying acetaminophen which is the treatment of choice for knee OA pain relief.'— Carlo Marra

In the April issue of the journal Arthritis Care & Research, researchers at the University of British Columbia and the University of Alberta asked pharmacists in Greater Vancouver and Edmonton to recruit people 50 or older who had pain, aching or discomfort in the knee lasting more than four weeks with previously undiagnosed knee osteoarthritis based on a review of medical charts.

A total of 190 participants were later confirmed to have knee OA by a rheumatologist and physiotherapist after a physical exam and radiographs.

Half of the participants took non-steroidal anti-inflammatory drugs or NSAIDs and 25 per cent tried acetaminophen, Carlo Marra, a UBC pharmacist and epidemiologist and his colleagues found.

Acetaminophen is the initial treatment of choice recommended in rheumatology guidelines because of its effectiveness, safety and low cost, the researchers said.

"Most concerning was the greater number of participants who opted to first use NSAIDs prior to trying acetaminophen, which is the treatment of choice for knee OA pain relief,” Marra said in a release.

Treatment of choice concern

By the end of the six-month period, 50 per cent of study subjects said that the analgesics and natural supplements helped in managing their knee OA. Significant improvements were seen in pain and usual activity scores after six months compared to before the study began.

About three-quarters of these study participants started exercising, one-third started using activity aids such as taping their knee or acupuncture, and one-third started taking natural medicine products.

In 52 per cent of the subjects, pain relief was started, including 36 per cent who started taking the natural supplements glucosamine or glucosamine with chondroitin, and 66 per cent who started both supplements and analgesics.

Medication reviews

"While a variety of different individuals were credited with recommending interventions for the management of OA, more than 50 per cent of the participants stated that they decided to start exercising, using activity aids, or taking analgesic medication on their own," the researchers wrote.

The limited involvement of pharmacists in patient care was unexpected since pharmacists were the first point of contact for participants, Marra said.

Medication reviews by a pharmacist can reduce potentially dangerous use of NSAIDS in those with knee OA, according to a previous study. The latest study did not assess precautions for using acetaminophen, such as liver problems.

Exercise advice

The findings also suggest many participants were not advised to become more physically active or did not consider the advice from health-care professionals.

"Whether perception or reality, the observation is important to consider in developing arthritis management programs that target early disease management," the researchers concluded.

Of the participants, 43 per cent were considered overweight and 24 per cent were obese, based on their body mass index.

The questionnaire did not ask about frequency, appropriateness or consistency of the exercise regimens, but the findings suggest people are open to trying exercise-based lifestyle interventions, especially after diagnosis, the researchers said.

Receiving a diagnosis of a chronic condition may have provided motivation to increase physical activity levels, and some may have already been contemplating lifestyle changes such as losing weight.

The study's authors acknowledged participants self-reported on their interventions and likely overestimated involvement in activities such as exercise.

The researchers are preparing a randomized controlled trial of a multidisciplinary approach to managing knee OA. To that end, this pilot study assessed whether pharmacists could reliably identify participants with undiagnosed knee OA.

Osteoarthritis affects an estimated three million people, which amounts to roughly one in 10 Canadians, according to the Arthritis Society.

The research was funded in part by the Canadian Institutes of Health Research Team, and a grant from Merck Frosst Canada. The company had no role in the study design, analysis or interpretation of the data.