How often do we hear that chiropractic is safe because numerous trials reported no adverse events? This systematic review tested whether there has been a change in the reporting of adverse events associated with spinal manipulation in randomized clinical trials (RCTs) since 2016.

Databases were searched from March 2016 to May 2022: MEDLINE (Ovid), Embase, CINAHL, ICL, PEDro, and Cochrane Library. Domains of interest (pertaining to adverse events) included: completeness and location of reporting; nomenclature and description; spinal location and practitioner delivering manipulation; methodological quality of the studies and details of the publishing journal. Frequencies and proportions of studies reporting on each of these domains were calculated. Univariable and multivariable logistic regression models were fitted to examine the effect of potential predictors on the likelihood of studies reporting on adverse events.

5399 records were identified by the electronic searches, of which 154 (2.9%) were included in the analysis. Of these, 94 (61.0%) reported adverse events with only 23.4% providing an explicit description of what constituted an adverse event. Reporting of adverse events in the abstract has increased (n=29, 30.9%) while reporting in the results section has decreased (n=83, 88.3%) over the past 6 years. Spinal manipulation was delivered to 7518 participants in the included studies. No serious adverse events were reported in any of these studies.

The authors concluded as follows: while the current level of reporting of adverse events associated with spinal manipulation in RCTs has increased since our 2016 publication on the same topic, the level remains low and inconsistent with established standards. As such, it is imperative for authors, journal editors and administrators of clinical trial registries to ensure there is more balanced reporting of both benefits and harms in RCTs involving spinal manipulation.

This article is clearly relevant to our discussions about adverse events after spinal manipulation. However, I find it far too uncritical. This might be due to the affiliations of some of the authors:

  • Integrative Spinal Research Group, Department of Chiropractic Medicine, University Hospital Balgrist and University of Zurich, Zurich, Switzerland.
  • Department of Chiropractic, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia.

Interestingly, the authors stated that they have no conflict of interest. Also interesting is the fact that they do not cite our paper from 2012. I, therefore, take the liberty of doing it:

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.

In percentage terms the results are similar. What is very different is that the authors of the new paper merely lament that the level remains low and inconsistent with established standards, while we make it clear in the abstract that adverse effect reporting is poor and in the paper identify this deficit as a violation against research ethics and thus as a form of scientific misconduct.

In view of all this, let me re-phrase the last sentence of the authors’ conclusion:

it is imperative for authors, journal editors, and administrators of clinical trial registries to ensure that researchers adhere to accepted ethical standards and that scientific misconduct no longer gets published.

11 Responses to Scientific misconduct by chiropractors or osteopaths should no longer get published

  • Interesting, what is the standard (vs the ideal)?

    “The median percentage of published documents with adverse events information was 46% compared to 95% in the corresponding unpublished documents. There was a similar pattern with unmatched studies, for which 43% of published studies contained adverse events information compared to 83% of unpublished studies.”

    “Finally, only between 3% and 33% of the total number of investigator-reported adverse events from the trials were reported in the publications because of post hoc filters, though six of seven papers stated that “all adverse events were recorded.”

    “Among the remaining 139 trials, for 44 (32 %), the number of SAEs per group published did not match those posted at For 31 trials, the number of SAEs was greater at than in the published article, with a difference ≥30 % for at least one group for 21.”

    “Sixty-two per cent reported some form of spontaneous AE collection but only 29% included details of specific prompts used to ascertain AE data. Numbers that withdrew from the trial were well reported (80%), however only 35% of these reported whether withdrawals were due to AEs.”

    • 1) tu quoque fallacy (because my neighbor is nasty to his wife, my wife-beating is less offensive)
      2) AE-reporting in trials might be less crucial in areas of healthcare with post-marketing surveillance than in areas without it

      • The call is for chiropractic researchers to adhere to the “acceptable ethical standard”. So it’s logical to ask…what is this standard? Such a request is not a fallacy.

        standard: usual rather than special (Cambridge)

        The examples I gave gives an indication of what the “standard” is in medical research.

        • Yes, many researchers fail to adhere to good standards.
          As I am writing about SCAM, my appeal for improvement is to SCAM researchers.

          • Sure, but if one is demanding chiropractic researchers to be held to a standard one has to know the standard.

            Or is there a double standard at play here?

  • As a victim of Chiropractic, I appreciate you drawing attention to the tainted and so often misguided “studies and reviews” by these “unbiased” authors.

    Indeed, this is yet another exposure, as you say of scientific misconduct, perpetuating a long-established distorted view on the merits of Chiropractic.

    It’s right up there with their automatic claim of a “pre-existing condition ” when disaster does strike.

    So much for ensuring the highest “Standard of Care”. Tell that to those who have suffered needless chiro “treatments” and ended up screwed for life.

    • Let me break it down this way. There are 4 possible scenarios. I will use VAD as an example.

      1. The VAD was present prior the cSMT and the symptoms were the reason they sought care
      2. The VAD occurred during the cSMT and was due to cSMT
      3. The VAD occurred after the cSMT and cSMT was a factor in causing the VAD
      4. The VAD occurred after the cSMT but cSMT was not a factor

      Due to the nature of the condition and the limitations of diagnostic investigation it is very difficult and sometimes impossible to know which scenario occurred. When someone claims that cSMT caused a VAD I question what evidence they have to make that claim. Typically the “evidence” is inadequate to claim causation. Sometimes there is enough evidence to claim a high probability of causation.

      My interest is…when cSMT is, or appears to have a high probability to be, causative of a VAD, why did it occur?

      • Considering the relatively young age of most of the VAD events associated with cSMT than those VADs not associated with cSMT, the most suspected scenarios must be 2 and 3.

        >”Due to the nature of the condition and the limitations of diagnostic investigation it is very difficult and sometimes impossible to know which scenario occurred”

        Precisely for that reason cSMT is contraindicated on patients having symptoms that may herald an imminent or present VAD (as in scenario 1).

        How can any non-monster human being dare put patients at risk of stroke, paralysis and death? I would be scared to death myself!

        • My sentiments exactly!

        • SOK: Considering the relatively young age of most of the VAD events associated with cSMT than those VADs not associated with cSMT

          A few facts

          The typical chiropractic patient is between 38 and 45 years of age and approximately 60% are female. Thus, one would expect to see a higher association with chiropractic care based on demographics.

          People in MVAs also seek out chiropractic care. Since MVAs account for approximately half of all VADs one would expect to see a higher association.

          VADs can mimic MSK issues and thus can be difficult to identify not only in chiropractic clinics but also in PCP clinics and ERs. Some research indicates that VADs associated with cSMT are more mild than other associations indicating these may not be as easy to identify.

          Most published cases indicate that the cSMT was performed in the presence of contraindications. This looks to be the fault of the individual chiropractor, not of the procedure. Some cases there was an improper technique. Again, that is the fault of the individual chiropractor.

          Not one published case has ever concluded causation based upon objective evidence.

          There are published cases where the VAD was suspected by a chiropractor, prior to manipulation, and later confirmed by imaging.

          I won’t go thru the math (busy right now) but there are around 40 million visits to a chiropractor each year in the USA for neck issues. Yet often research on this topic struggles to find enough cases to run a proper analysis.

          Chiropractors are seldom notified that a patient was diagnosed with a VAD after care. This may be for several reasons.

          • Perfectly young healthy wife routinely goes for something the Chiropractor calls “maintenance treatments”.
            Her standard treatment consists of the usual stretching but always ends with a rapid upper neck manipulation.
            Fifteen years later and much regret for ever listening to this ” doctors” advice.
            In Sandy Nettes tragic case, she never even suffered from headaches.
            Again, this procedure was recommended and encouraged for maintaining great health.

            It’s time to stop making excuses and abolish this senseless neck twisting practice.

            Unfortunately I feel the Chiropractic folks need to keep this bizarre technique in their portfolio in order to give them some sort of relevance or definition.

            Commen sense is not so common.

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