Methods of Treating Chronic Pain: A Systematic Review [Internet]

Conclusions How Patients Experience Chronic Pain

1. The research on treating chronic pain unequivocally demonstrates a strong negative correlation between pain and quality of life, i.e., pain reduction improves quality of life (strong scientific evidence).

2. Living with chronic pain requires a new orientation in life and the opportunity to talk about the experience (moderately strong scientific evidence).

3. Patients with chronic pain are eager to retain their sense of dignity (strong scientific evidence).

Multimodal Rehabilitation

1. The long-term impact of broad-based, coordinated rehabilitation programs, referred to as multimodal rehabilitation (usually a combination of psychological interventions and physical activity, physical exercise or physical therapy) is that pain decreases more, a greater number of people return to work and sick leaves are shorter than with passive control and/or limited, separate interventions (strong scientific evidence). Because the studies on which that conclusion is based were structured in various different ways, any attempt to compare the magnitude of the effects may be misleading.

2. Multimodal rehabilitation improves long-term functional ability in fibromyalgia patients more effectively than passive control or limited, separate interventions (moderately strong scientific evidence).

Cognitive Behavioral Therapy

1. Cognitive behavioral therapy yields better social and physical function, as well as 25% greater ability to cope, in chronic pain patients than other behavioral therapies, medications and physical therapy that have been studied and to no treatment at all (moderately strong scientific evidence).

Drugs

1. Paracetamol (acetaminophen) somewhat (effect size 0.21)* alleviates the pain of mild to moderate osteoarthritis (strong scientific evidence). Paracetamol is more effective in combination with tramadol or another weak opioid than as monotherapy (strong scientific evidence).

2. COX-2 inhibitors and other nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the pain of osteoarthritis and arthritis by at least 30% (strong scientific evidence). Combining them with tramadol or another weak opioid can increase their effectiveness (strong scientific evidence). All COX-2 inhibitors and other NSAIDs increase the risk of cardiovascular events (strong scientific evidence). There is insufficient scientific evidence to draw any conclusions concerning possible differences between various classes of drugs.

3. COX-2 inhibitors can be a cost-effective option for chronic pain patients with a high risk of gastrointestinal bleeding (moderately strong scientific evidence).

4. Amitriptyline reduces the pain of peripheral and central neuropathic pain due to shingles (herpes zoster), diabetes and stroke patients by more than 20% (moderately strong scientific evidence).

5. Tricyclic antidepressants moderately alleviate fibromyalgia pain (moderately strong scientific evidence).

6. Strong opioids – number needed to treat (NNT)** approximately 2.6 – alleviate neuropathic pain in diabetes and shingles patients (strong scientific evidence). Strong opioids reduce severe osteoarthritis pain by approximately 24% (strong scientific evidence). Weak opioids reduce mild to moderate osteoarthritis and low back pain by approximately 40% (strong scientific evidence). They are just as effective as NSAIDs for osteoarthritis pain (strong scientific evidence). Both weak and strong opioids cause unpleasant adverse effects (the most common of which are constipation, fatigue, dizziness, nausea and vomiting) in more than half of all patients (strong scientific evidence).

7. Carbamazepine is effective (NNT 1.4–2.8) in trigeminal neuralgia (tic douloureux) (moderately strong scientific evidence). Gabapentin (Neurontin) reduces neuropathic pain (NNT 3.8 for at least 50%) in diabetes (moderately strong scientific evidence) and in patients with post-herpetic (NNT 3.2) pain (strong scientific evidence).

8. Tramadol is more effective than placebo for nociceptive pain – approximately 20% of tramadol patients, as opposed to 40% of placebo patients, stop taking their medication due to insufficient relief (strong scientific evidence). Tramadol alleviates neuropathic pain (NNT 4.3 for at least 50% pain relief) (limited scientific evidence). Tramadol is as effective as weak opioids for musculoskeletal pain (strong scientific evidence). Tramadol causes adverse effects to the same extent as weak and strong opioids (strong scientific evidence).

9. Capsaicin reduces (NNT 8 for at least 50%) neuropathic pain and osteoarthritis pain in small joint pain (strong scientific evidence).

10. The research results are contradictory when it comes to the effectiveness of glucosamine in relieving osteoarthritis pain.

Medical instruments

1. Spinal cord stimulation reduces the frequency of angina attacks by 50% and improves quality of life, both short-term and long-term, in patients with severe angina pectoris or the ischemic symptoms of peripheral arterial disease (strong scientific evidence).

2. Radiofrequency denervation (limited scientific evidence) can provide short-term relief of chronic neck and back (including whiplash-related) pain but poses a risk of serious complications.

3. Physical Activity, Physical Exercise, Relaxation, biofeedback, Massage, Manipulation, Physical Therapy and Orthosis Active, specific and professionally supervised exercise alleviates chronic pain 20–30% more effectively than treatment that does not involve physical activity (strong scientific evidence).

4. Treatment strategies that include physical activity are more cost-effective in alleviating chronic low back pain than standard primary care that does not involve specific measures (limited scientific evidence).

Acupuncture

1. Western acupuncture alleviates chronic low back pain more effectively than placebo (strong scientific evidence).

2. There is strong scientific evidence that acupuncture alleviates low back pain, lateral epicondylitis (tennis elbow), neck and shoulder pain as effectively as other treatments.

Other Methods

1. Balneotherapy (mud or mineral baths) reduces chronic musculoskeletal pain by 20–30% (limited scientific evidence).

Odontological Methods

1. In orofacial pain, occlusal splints and behavioral therapies such as biofeedback and cognitive behavioral therapy give better pain relief than no therapy at all (limited scientific evidence).

Chronic Pain in Children

1. Psychological methods (NNT 2.35) alleviate tension (muscle contraction) headaches in children more effectively than placebo, standard primary care (which does not involve specific measures) or no treatment at all (strong scientific evidence).

* Effect size: <0.20: insignificant; 0.20–0.50: small; 0.50–0.80: moderate; >0.80: large. Source: Treatment of Alcohol and Drug Abuse, SBU Report 156/2, 2001, pp 403-5. ** Number of patients who must be treated before one of them is likely to benefit. The lower, the better.