Thursday, February 12, 2009
rugpijn
Hancock MJ, Maher GC, Latimer J, et al
Lancet. 2007;370:1638-1643
Previous recommendations have noted that nonsteroidal anti-inflammatory drugs (NSAIDs) and spinal manipulation therapy can be helpful for patients with acute low back pain, but the current study compares this approach with a "usual care" group, who received advice on physical activity and regular doses of paracetamol. The researchers' findings are surprising and should change the way clinicians think about the management of low back pain.
This study was selected from Medscape Best Evidence, which uses the McMaster Online Rating of Evidence System. Of a possible top score of 7, this study was ranked as 6 for relevance and 5 newsworthiness by clinicians who used this system.
Commentary
Low back pain is one of the most common and difficult to treat conditions encountered in the acute care setting. The lifetime prevalence of low back pain is between 60% and 85%, and 15% of the population may have low back pain at any one time.[1] This complaint also exacts a significant toll on society at large. In an analysis of the cost of medical conditions to American businesses in terms of medical visits, prescription drug use, absence from work, and short-term disability, mechanical low back pain ranked number 4 on the top 10 most costly physical diagnoses.[2] Moreover, "other" back pain and spinal injury were also in the top 10.
Current recommendations for the management of low back pain include early mobilization and physical activity.[1] Acetaminophen, NSAIDs, and muscle relaxants are recommended to reduce pain and improve function within the first 6 weeks after the manifestation of acute symptoms. Spinal manipulation therapy is also often recommended in such cases. Such treatments, however, cannot prevent the development of nonspecific low back pain or chronic back pain among patients with acute pain. Prevention of chronic back pain focuses more on behavior and maintenance of activity as opposed to pharmacotherapy.
NSAIDs have been demonstrated to improve low back pain compared with placebo, according to a 2008 systematic review by the Cochrane Collaboration Review Group.[3] Researchers analyzed 65 trials involving a total of 11,237 patients with low back pain. Overall, NSAIDs were more effective than placebo in the management of acute low back pain. However, NSAIDs also increased the risks for adverse events compared with placebo.
These improvements using NSAIDs vs. placebo are modest, and whether NSAIDs confer greater benefit than acetaminophen (paracetamol) is controversial. The review cites 6 studies that investigated this issue, only one of which was of high quality. Most of these studies focused on acute low back pain and failed to demonstrate superiority of one treatment over another. The one high-quality study examined patients with chronic low back pain, not acute pain, and NSAIDs were more effective than paracetamol in this group.
The body of research into the efficacy of spinal manipulative therapy is more complicated and difficult to interpret. The techniques for manipulative therapy are more heterogenous than medical therapy, and studies have compared manipulative therapy with multiple different control treatments, making it difficult to draw a conclusion regarding treatment efficacy. However, one review classified control treatments from studies of spinal manipulative therapy into 7 broad categories and pooled results from 39 randomized controlled trials.[4] Spinal manipulative therapy was significantly superior to sham therapy, resulting in a mean of 10 mm of improvement vs sham therapy on a 100-mm pain scale. However, spinal manipulation therapy was not superior to general practitioner care, analgesics, physical therapy, back exercises, or back school. The authors examined variables affecting pain outcomes, and they found that the profession of the person performing spinal manipulation did not alter the main study result.
Together, these reviews of NSAIDs and spinal manipulative therapy do not provide overwhelming evidence of superior efficacy of either treatment over good routine care of acute low back pain. Furthermore, the current study puts these treatments to the test in a common practice environment. Patients seeking relief of acute low back pain in general practitioners' offices were eligible for study participation. Those with a history of back pain in the month prior to study enrollment or evidence of nerve root compromise on physical examination were excluded.
All participants were given paracetamol 1 gm to be taken 4 times daily until complete recovery or a maximum of 4 weeks elapsed. Subjects were assigned to receive diclofenac 50 mg twice daily and placebo spinal manipulation therapy, spinal manipulation therapy and placebo tablets imitating diclofenac, or double placebo. Spinal manipulation therapy was delivered 2 or 3 times per week and allowed for the use of high-velocity thrust procedures according to the judgment of experienced physiotherapists. The placebo used to replace spinal therapy was detuned pulse ultrasound.
The primary outcome was the number of days until either the first pain-free day or the first of 7 consecutive days with at least minimal pain. Secondary outcomes included pain, function, and disability.
There were 240 patients with moderate levels of pain and disability at baseline who underwent randomization. On average, subjects took approximately two thirds of the recommended dose of paracetamol and 72% of the recommended dose of diclofenac. The median number of spinal manipulation therapy sessions per week was 2.3, and only a small percentage of subjects underwent high-velocity thrust techniques.
Patients had difficulty discerning placebo from active treatments, indicating that the blinding techniques were adequate. The median number of days to recovery among subjects receiving diclofenac was 13, compared with 16 days among participants receiving placebo, which was not a statistically significant difference. In both the spinal manipulation therapy group and the placebo group, the median number of days to recovery was 15. Even the combination of diclofenac and spinal manipulation therapy failed to promote faster rates of improvement vs double placebo. Moreover, both active treatments failed to improve secondary outcomes of pain, disability, or function compared with placebo. Participants reported that the overall perceived effect was similar regardless of study treatment.
The authors of the current study address a major reason for the negative results in their study compared with results of previous research on NSAIDs for acute low back pain. They note that many of these earlier trials failed to include clinicians' advice for basic back care as well as regular treatment with paracetamol. Although NSAIDs and spinal manipulation therapy may be more effective than placebo, the current research suggests that they are no more effective than paracetamol and sound advice.
At the same time, NSAIDs raise significant safety concerns. The prevalence of NSAID-related gastropathy is approximately 25% to 50% among chronic NSAID users. Furthermore, a meta-analysis that examined the gastrointestinal risk associated with specific NSAIDs found that NSAIDs increased the risk for all gastrointestinal complications by 54%.[5] The NSAIDs most associated with these complications were (in order of the frequency of complications) indomethacin, naproxen, and diclofenac. The relative risk for gastrointestinal complications with indomethacin reached its maximum after only 14 days of therapy. Tenoxicam, meloxicam, and ibuprofen produced nonsignificant increases in the risk for gastrointestinal complications.
NSAIDs can have deleterious effects on the kidneys as well. A study of 90 patients with osteoarthritis examined renal function when patients were treated with amtolmetin guacyl (the prodrug of tolmetin), diclofenac, or rofecoxib for 17 days.[6] Researchers found that diclofenac was associated with an increase in serum creatinine and a reduction in daily urine volume. Rofecoxib, which was withdrawn from the market in 2004, increased blood pressure values while reducing daily urine volume and creatinine clearance. However, amtolmetin did not significantly affect any of the parameters of renal function.
Spinal manipulation therapy also has possible adverse consequences. In a review of the medical literature regarding spinal manipulation therapy published between 2001 and 2006, researchers found that more than 200 patients receiving spinal manipulation were suspected to have been seriously harmed.[7] Most data regarding serious adverse effects were from case reports, and vertebral artery dissection was identified as the most common serious adverse event. Mild adverse events of spinal manipulation therapy were very common, occurring in 30% to 61% of all patients. However, some clinical trials of spinal manipulation therapy have demonstrated that these techniques are safe for the management of low back pain.[8,9]
However, the more pertinent question regarding the possible negative consequences of spinal manipulation therapy may be financial. One of the larger trials focusing on the effectiveness of spinal manipulation therapy for back pain included a financial analysis.[10] This study involved 181 general practices in the United Kingdom. The researchers found that mean annual treatment costs relative to standard clinical care were 195 pounds sterling for spinal manipulation. However, spinal manipulation improved the outcome of quality-adjusted life years vs best care, and the authors concluded that spinal manipulation is a cost-effective addition to "best care" for back pain in general practice. Moreover, the researchers found that spinal manipulation alone improved therapeutic value for the money compared with manipulation followed by a supervised exercise program.
Another study conducted by chiropractic researchers in the United States found that chiropractic care was more expensive than medical care for patients with both acute and chronic low back pain.[11] However, at the same time, patients with chronic low back pain receiving chiropractic care experienced better outcomes in pain and functional disability compared with patients receiving medical care exclusively. The authors conclude that chiropractic care appears cost-effective for chronic low back pain, although it may not be as cost-effective for patients with acute low back pain.
The current study by Hancock and colleagues would certainly suggest that the added cost and adverse events associated with spinal manipulation therapy are not justified by more rapid improvement in low back pain. In addition, the study suggests that patients should not be exposed to the risk of taking NSAIDs when there is little added therapeutic benefit associated with such treatment. It is also worth noting that recent research into the early prescribing of opioids for low back pain found this practice to be associated with higher mean disability duration, elevated mean medical costs, and an increased risk for surgery and late opioid use compared with usual practice.[12]
Although it may be difficult for both patients and providers to accept that time appears to be the best therapy for low back pain, most cases of back pain improve significantly within 2 weeks, and 90% of patients report significant improvement at 2 months.[1] Clinicians should certainly encourage appropriate activity and recommend paracetamol/acetaminophen to improve symptoms of acute low back pain, but it appears that giving the body time to recover is the key element of treatment. This common diagnosis requires prescriptive restraint, and patients will benefit from this practice in the long run.
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