The WHO has just released guidelines for non-surgical management of chronic primary low back pain (CPLBP). The guideline considers 37 types of interventions across five intervention classes. With the guidelines, WHO recommends non-surgical interventions to help people experiencing CPLBP. These interventions include:

• education programs that support knowledge and self-care strategies;
• exercise programs;
• some physical therapies, such as spinal manipulative therapy (SMT) and massage;
• psychological therapies, such as cognitive behavioural therapy; and
• medicines, such as non-steroidal anti-inflammatory medicines.

The guidelines also outline 14 interventions that are not recommended for most people in most contexts. These interventions should not be routinely offered, as WHO evaluation of the available evidence indicate that potential harms likely outweigh the benefits. WHO advises against interventions such as:

• lumbar braces, belts and/or supports;
• some physical therapies, such as traction;
• and some medicines, such as opioid pain killers, which can be associated with overdose and dependence.

As you probably guessed, I am particularly intrigued by the WHO’s positive recommendation for SMT. Here is what the guideline tells us about this specific topic:

Considering all adults, the guideline development group (GDG) judged overall net benefits [of spinal manipulation] across outcomes to range from trivial to moderate while, for older people the benefit was judged to be largely uncertain given the few trials and uncertainty of evidence in this group. Overall, harms were judged to be trivial to small for all adults and uncertain for older people due to lack of evidence.

The GDG commented that while rare, serious adverse events might occur with SMT, particularly in older people (e.g. fragility fracture in people with bone loss), and highlighted that appropriate training and clinical vigilance concerning potential harms are important. The GDG also acknowledged that rare serious adverse events were unlikely to be detected in trials. Some GDG members considered that the balance of benefits to harms favoured SMT due to small to moderate benefits while others felt the balance did not favour SMT, mainly due to the very low certainty evidence for some of the observed benefits.

The GDG judged the overall certainty of evidence to be very low for all adults, and very low for older people, consistent with the systematic review team’s assessment. The GDG judged that there was likely to be important uncertainty or variability among people with CPLBP with respect to their values and preferences, with GDG members noting that some people might prefer manual
therapies such as SMT, due to its “hands-on” nature, while others might not prefer such an approach.

Based on their experience and the evidence presented from the included trials which offered an average of eight treatment sessions, the GDG judged that SMT was likely to be associated with moderate costs, while acknowledging that such costs and the equity impacts from out-of-pocket costs would vary by setting.

The GDG noted that the cost-effectiveness of SMT might not be favourable when patients do not experience symptom improvements early in the treatment course. The GDG judged that in most settings, delivery of SMT would be feasible, although its acceptability was likely to vary across
health workers and people with CPLBP.

The GDG reached a consensus conditional recommendation in favour of SMT on the basis of small to moderate benefits for critical outcomes, predominantly pain and function, and the likelihood of rare adverse events.

The GDG concluded by consensus that the likely short-term benefits outweighed potential harms, and that delivery was feasible in most settings. The conditional nature of the recommendation was informed by variability in acceptability, possible moderate costs, and concerns that equity might be negatively impacted in a user-pays model of financing.

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This clearly is not a glowing endorsement or recommendation of SMT. Yet, in my view, it is still too positive. In particular, the assessment of harm is woefully deficient. Looking into the finer details, we find how the GDG assessed harms:

WHO commissioned quantitative systematic evidence syntheses of randomized controlled
trials (RCTs) to evaluate the benefits and harms (as reported in included trials) of each of the
prioritized interventions compared with no care (including trials where the effect of an
intervention could be isolated), placebo or usual care for each of the critical outcomes (refer to Table 2 for the PICO criteria for selecting evidence). Research designs other than RCTs
were not considered.

That explains a lot!

It is not possible to establish the harms of SMT (or any other therapy) on the basis of just a few RCTs, particularly because the RCTs in question often fail to report adverse events. I can be sure of this phenomenon because we investigated it via a systematic review:

Objective: To systematically review the reporting of adverse effects in clinical trials of chiropractic manipulation.

Data sources: Six databases were searched from 2000 to July 2011. Randomised clinical trials (RCTs) were considered, if they tested chiropractic manipulations against any control intervention in human patients suffering from any type of clinical condition. The selection of studies, data extraction, and validation were performed independently by two reviewers.

Results: Sixty RCTs had been published. Twenty-nine RCTs did not mention adverse effects at all. Sixteen RCTs reported that no adverse effects had occurred. Complete information on incidence, severity, duration, frequency and method of reporting of adverse effects was included in only one RCT. Conflicts of interests were not mentioned by the majority of authors.

Conclusions: Adverse effects are poorly reported in recent RCTs of chiropractic manipulations.

The GDG did not cite our review (or any other of our articles on the subject) but, as it was published in a very well-known journal, they must have been aware of it. I am afraid that this wilfull ignorance caused the WHO guideline to underestimate the level of harm of SMT. As there is no post-marketing surveillance system for SMT, a realistic assessment of the harm is far from easy and needs to include a carefully weighted summary of all the published reports (such as this one).

The GDG seems to have been aware of (some of) these problems, yet they ignored them and simply assumed (based on wishful thinking?) that the harms were small or trivial.

Why?

Even the most cursory look at the composition of the GDG, begs the question: could it be that the GDG was highjacked by chiropractors and other experts biased towards SMT?

The more I think of it, the more I feel that this might actually be the case. One committee even listed an expert, Scott Haldeman, as a ‘neurologist’ without disclosing that he foremost is a chiropractor who, for most of his professional life, has promoted SMT in one form or another.

Altogether, the WHO guideline is, in my view, a shameful example of pro-chiropractic bias and an unethical disservice to evidence-based medicine.