By Colleen Donder

Approximately 20 per cent of Canadians live with chronic pain, which is defined as pain that lasts longer than three months. The symptoms of chronic pain can be more than just physical. People with chronic pain typically find that their quality of life is reduced, and they are unable to do normal everyday activities because of their pain. They also often experience mental health–related symptoms.

Chronic pain is difficult to cure, and its management often involves different types of non-drug and drug therapies. Non-drug therapies can fall into different categories, such as physical, psychological, and preventive treatments. With so many different options, it can be difficult to know what therapies work for what type of pain. CADTH – an independent agency that finds, assesses, and summarizes the research on drugs, medical devices, tests, and procedures – looked at the evidence for nine different non-drug interventions for chronic pain.

As an example, one of the interventions CADTH reviewed was exercise, specifically for managing knee osteoarthritis pain. Osteoarthritis is caused by the wearing down of cartilage in the joints of the body and the thickening of the bones underneath. It can cause pain, stiffness, and swelling. Osteoarthritis typically affects the hands, feet, knees, spine, and hips; but the knee is most commonly affected. The pain, joint stiffness, instability, and decrease in function from knee osteoarthritis can cause disability and reduce a person’s ability to participate in physical activities.

There are different treatments available for knee osteoarthritis to help decrease pain and improve the joint’s ability to move. Common drug therapies include pain and anti-inflammatory medications (e.g., acetaminophen and ibuprofen). In addition to exercise, non-drug therapies include physiotherapy, weight loss or healthy weight programs, and self-management programs. When the damage to the knee is severe, surgery to replace the joint may be recommended. Even though there are many treatment options, exercise is one of the core non-drug therapies that is recommended for knee osteoarthritis pain, in part because it is considered safer than some of the drug therapy options.

CADTH was asked to look at the evidence to see if exercise for chronic knee osteoarthritis pain is effective and safe. CADTH found two systematic reviews and one systematic umbrella review that were best suited to help answer this question.

Overall, the evidence suggests that exercise may decrease pain and improve function, performance, and health-related quality of life for people with pain from knee osteoarthritis. The individual studies included in the reviews investigated several different types of exercises of different lengths and frequency; therefore, it is difficult to say if there are certain exercises that are better than others for knee osteoarthritis pain.

While the evidence suggests that exercise is effective for managing the pain from knee osteoarthritis, it is important to assess any potential risks. And the evidence CADTH identified related to safety indicates that low-impact exercise that combines muscle strengthening, stretching, and aerobic activity does not appear to cause serious side effects in older adults. Some studies found that there was a temporary increase in minor pain with exercise, but there was no difference in worsening pain, falls, or death.

Exercise is only one example of a non-drug therapy that may help manage pain from knee osteoarthritis — there are many others that might be effective. Non-drug therapies have also been studied for the management of pain associated with other chronic pain conditions. As mentioned, CADTH has conducted evidence reviews on many of these interventions — including acupuncture, manual therapy, mindfulness, cognitive behavioural therapy, yoga, splints and braces, healthy weight management, orthotics, and exercise. These reviews are conveniently summarized at www.cadth.ca/chronicpain.

To learn more about CADTH, please visit cadth.ca, follow us on Twitter @CADTH_ACTMS, or speak to a Liaison Officer in your region: cadth.ca/Liaison-Officers.

Colleen Donder is a knowledge mobilization officer at CADTH.