MD, PhD, FMedSci, FRSB, FRCP, FRCPEd.

osteoarthritis

This study describes the use of so-called alternative medicine (SCAM) among older adults who report being hampered in daily activities due to musculoskeletal pain. The characteristics of older adults with debilitating musculoskeletal pain who report SCAM use is also examined. For this purpose, the cross-sectional European Social Survey Round 7 from 21 countries was employed. It examined participants aged 55 years and older, who reported musculoskeletal pain that hampered daily activities in the past 12 months.

Of the 4950 older adult participants, the majority (63.5%) were from the West of Europe, reported secondary education or less (78.2%), and reported at least one other health-related problem (74.6%). In total, 1657 (33.5%) reported using at least one SCAM treatment in the previous year.

The most commonly used SCAMs were:

  • manual body-based therapies (MBBTs) including massage therapy (17.9%),
  • osteopathy (7.0%),
  • homeopathy (6.5%)
  • herbal treatments (5.3%).

SCAM use was positively associated with:

  • younger age,
  • physiotherapy use,
  • female gender,
  • higher levels of education,
  • being in employment,
  • living in West Europe,
  • multiple health problems.

(Many years ago, I have summarized the most consistent determinants of SCAM use with the acronym ‘FAME‘ [female, affluent, middle-aged, educated])

The authors concluded that a third of older Europeans with musculoskeletal pain report SCAM use in the previous 12 months. Certain subgroups with higher rates of SCAM use could be identified. Clinicians should comprehensively and routinely assess SCAM use among older adults with musculoskeletal pain.

I often mutter about the plethora of SCAM surveys that report nothing meaningful. This one is better than most. Yet, much of what it shows has been demonstrated before.

I think what this survey confirms foremost is the fact that the popularity of a particular SCAM and the evidence that it is effective are two factors that are largely unrelated. In my view, this means that more, much more, needs to be done to inform the public responsibly. This would entail making it much clearer:

  • which forms of SCAM are effective for which condition or symptom,
  • which are not effective,
  • which are dangerous,
  • and which treatment (SCAM or conventional) has the best risk/benefit balance.

Such information could help prevent unnecessary suffering (the use of ineffective SCAMs must inevitably lead to fewer symptoms being optimally treated) as well as reduce the evidently huge waste of money spent on useless SCAMs.

S-adenosyl methionine – SAMe for short – is a popular dietary supplement available freely via the Internet. It is a naturally occurring methyl radical donor involved in enzymatic transmethylation reactions in humans and animals. It has been used for treating postpartum depression, cholestatic jaundice, osteoarthritis, and numerous other conditions. SAM-e has poor oral bioavailability. SAM-e has so far been thought of as safe. The most frequent adverse effects reported were gastrointestinal, such as nausea, and skin rashes.

I have been involved in two systematic reviews that produced positive evidence for the effectiveness of SAMe:

Now the safety of SAMe has been questioned by new research. A team from Manchester and Kyoto universities reported that the supplement can break down inside the body into substances that cause a wide range of medical problems, including kidney and liver damage. Their study showed that “excess S-adenosylmethionine disrupts rhythms and, rather than promoting methylation, is catabolized to adenine and methylthioadenosine, toxic methylation inhibitors.”

Jean-Michel Fustin, of Manchester University, said experiments that he and his collaborators had carried out had revealed that SAMe breaks down into adenine and methylthioadenosine in the body. These substances are known to be toxic, he added. “This discovery came out of the blue,” Fustin said last week. “When we gave the supplement to mice we expected they would become healthier. But instead we found the opposite. We found that when SAMe breaks down in the body, it produces very toxic molecules, including adenine which causes gout, kidney disease and liver disease.” Fustin added that, although their study was carried out on mice, their results were relevant for humans. “We have not yet tested the supplement on men and women but we have added it to human cells in laboratory cultures and have found it had the same effect as it had on mice.”

Their study, which was funded by the Medical Research Council and the Japanese Society for the Promotion of Science, makes it clear that the health benefits of SAMe are questionable, to say the very least, Fustin added. “It is unclear what dose of it might be safe, so there is a good chance that a safe dose will be exceeded if someone takes this supplement – if a safe dose exists at all.”

This study describes the use of so-called alternative medicine (SCAM) among older adults who report being hampered in daily activities due to musculoskeletal pain. Cross-sectional European Social Survey (EES) Round 7 (2014) data from 21 countries were examined for participants aged 55 years and older, who reported musculoskeletal pain that hampered daily activities in the past 12months. From a total of 35,063 individuals who took part in the ESS study, 13,016 (37%) were aged 55 or older; of which 8183 (63%) reported the presence of pain, with a further 4950 (38%) reporting that this pain hampered their daily activities in any way.

Of the 4950 older adult participants reporting musculoskeletal pain that hampered daily activities, the majority (63.5%) were from the West of Europe, reported secondary education or less (78.2%), and reported at least one other health-related problem (74.6%). In total, 1657 (33.5%) reported using at least one SCAM treatment in the previous year. Manual body-based therapies (MBBTs) were most used, including massage therapy (17.9%) and osteopathy (7.0%). Alternative medicinal systems (AMSs) were also popular with 6.5% using homeopathy and 5.3% reporting herbal treatments. A general trend of higher SCAM use in younger participants was noted.

SCAM usage was associated with

  • physiotherapy use,
  • female gender,
  • higher levels of education,
  • being in employment,
  • living in West Europe
  • having multiple health problems.

The authors concluded that a third of older Europeans with musculoskeletal pain report SCAM use in the previous
12 months. Certain subgroups with higher rates of SCAM use could be identified. Clinicians should comprehensively and routinely assess SCAM use among older adults with musculoskeletal pain.

Such studies have the advantage of large sample sizes, and therefore one is inclined to consider their findings to be reliable and informative. Yet, they resemble big fishing operations where all sorts of important and unimportant stuff is caught in the net. When studying such papers, it is wise to remember that associations do not necessarily reveal causal relationships!

Having said this, I find very little information in these already outdated results (they originate from 2014!) that I would not have expected. Perhaps the most interesting aspect is the nature of the most popular SCAMs used for musculoskeletal problems. The relatively high usage of MBBTs had to be expected; in most of the surveyed countries, massage therapy is considered to be not SCAM but mainstream. The fact that 6.5% used homeopathy to ease their musculoskeletal pain is, however, quite remarkable. I know of no good evidence to show that homeopathy is effective for such problems (in case some homeopathy fans disagree, please show me the evidence).

In my view, this indicates that, in 2014, much needed to be done in terms of informing the public about homeopathy. Many consumers mistook homeopathy for herbal medicine (which btw may well have some potential for musculoskeletal pain), and many consumers had been misguided into believing that homeopathy works. They had little inkling that homeopathy is pure placebo therapy. This means they mistreated their conditions, continued to suffer needlessly, and caused an unnecessary financial burden to themselves and/or to society.

Since 2014, much has happened (as discussed in uncounted posts on this blog), and I would therefore assume that the 6.5% figure has come down significantly … but, as you know:

I am an optimist.

I believe in progress.

This randomized clinical trial tested the effects of laying on of hands (LooH) as a complementary therapy to kinesiotherapy, on pain, joint stiffness, and functional capacity of older women with knee osteoarthritis (KOA) compared to a control group.

Participants were assigned into 3 groups:

  1. LooH with a spiritual component (Group – SPG),
  2. LooH without a spiritual component (Group – LHG),
  3. a control group receiving no complementary intervention (Control Group – CG).

Patients were assessed at baseline, 8 weeks, and 16 weeks. Primary outcomes were joint stiffness and functional capacity (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), and pain (WOMAC and visual analogue scale). Secondary outcomes were anxiety, depression, mobility, and quality of life. Differences between groups were evaluated using an intention-to-treat approach.

A total of 120 women with KOA were randomized (40 participants per group). At 8 weeks, SPG differed significantly from the LHG for WOMAC Functional Status; Anxiety levels; and also from the CG for all outcomes with exception of WOMAC Stiffness. After 16 weeks, SPG differed significantly from the LHG only for WOMAC Functional Status and also from the CG for all outcomes with exception of WOMAC Stiffness and timed up-and-go.

The authors concluded that the results suggest that LooH with a “spiritual component” may promote better long-term functional outcomes than both LooH without a “spiritual component” and a control group without LooH.

This is an interesting study which seems well designed. Its findings are surprising and lack scientific plausibility. Therefore, sceptics will find it hard to accept the results and suspect some hidden bias or confounding to have caused it rather than the laying on of hands. SCAM enthusiasts would then probably claim that such an attitude exemplifies the bias of sceptics.

So, what can be done to find out who is right and who is wrong?

Whenever we are faced with a surprising finding based on a seemingly rigorous trial, it is wise to realise that there  is a plethora of possible explanations and that speculations are usually not very helpful. There is always a danger of a clinical trial producing false or misleading findings. This could be due to a plethora of reasons such as error, undetected bias or confounding, fraud, etc.

What we really need is an independent replication – better two.

Much of so-called alternative medicine (SCAM) is used in the management of osteoarthritis pain. Yet few of us ever seem to ask whether SCAMs are more or less effective and safe than conventional treatments.

This review determined how many patients with chronic osteoarthritis pain respond to various non-surgical treatments. Published systematic reviews of randomized controlled trials (RCTs) that included meta-analysis of responder outcomes for at least 1 of the following interventions were included: acetaminophen, oral nonsteroidal anti-inflammatory drugs (NSAIDs), topical NSAIDs, serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, cannabinoids, counselling, exercise, platelet-rich plasma, viscosupplementation (intra-articular injections usually with hyaluronic acid ), glucosamine, chondroitin, intra-articular corticosteroids, rubefacients, or opioids.

In total, 235 systematic reviews were included. Owing to limited reporting of responder meta-analyses, a post hoc decision was made to evaluate individual RCTs with responder analysis within the included systematic reviews. New meta-analyses were performed where possible. A total of 155 RCTs were included. Interventions that led to more patients attaining meaningful pain relief compared with control included:

  • exercise (risk ratio [RR] of 2.36; 95% CI 1.79 to 3.12),
  • intra-articular corticosteroids (RR = 1.74; 95% CI 1.15 to 2.62),
  • SNRIs (RR = 1.53; 95% CI 1.25 to 1.87),
  • oral NSAIDs (RR = 1.44; 95% CI 1.36 to 1.52),
  • glucosamine (RR = 1.33; 95% CI 1.02 to 1.74),
  • topical NSAIDs (RR = 1.27; 95% CI 1.16 to 1.38),
  • chondroitin (RR = 1.26; 95% CI 1.13 to 1.41),
  • viscosupplementation (RR = 1.22; 95% CI 1.12 to 1.33),
  • opioids (RR = 1.16; 95% CI 1.02 to 1.32).

Pre-planned subgroup analysis demonstrated no effect with glucosamine, chondroitin, or viscosupplementation in studies that were only publicly funded. When trials longer than 4 weeks were analysed, the benefits of opioids were not statistically significant.

The authors concluded that interventions that provide meaningful relief for chronic osteoarthritis pain might include exercise, intra-articular corticosteroids, SNRIs, oral and topical NSAIDs, glucosamine, chondroitin, viscosupplementation, and opioids. However, funding of studies and length of treatment are important considerations in interpreting these data.

Exercise clearly is an effective intervention for chronic osteoarthritis pain. It has consistently been recommended by international guideline groups as the first-line treatment in osteoarthritis management. The type of exercise is likely not important.

Pharmacotherapies such as NSAIDs and duloxetine demonstrate smaller but statistically significant benefit that continues beyond 12 weeks. Opioids appear to have short-term benefits that attenuate after 4 weeks, and intra-articular steroids after 12 weeks. Limited data (based on 2 RCTs) suggest that acetaminophen is not helpful. These findings are consistent with recent Osteoarthritis Research Society International guideline recommendations that no longer recommend acetaminophen for osteoarthritis pain management and strongly recommend against the use of opioids.

Limited benefit was observed with other interventions including glucosamine, chondroitin, and viscosupplementation. When only publicly funded trials were examined for these interventions, the results were no longer statistically significant.

Adverse events were inconsistently reported. However, withdrawal due to adverse events was consistently reported and found to be greater in patients using opioids, SNRIs, topical NSAIDs, and viscosupplementation.

Few of the interventions assessed fall under the umbrella of so-called alternative medicine (SCAM):

  • some forms of exercise,
  • cannabinoids,
  • counselling,
  • chondroitin,
  • glucosamine.

It is unclear why the authors did not include SCAMs such as chiropractic, osteopathy, massage therapy, acupuncture, herbal medicines, neural therapy, etc. in their review. All of these SCAMs are frequently used for osteoarthritis pain. If they had included these treatments, how do you think they would have fared?

“Unless positive evidence emerges, the risk/benefit balance of ozone therapy for any condition fails to be positive.”  This is the conclusion I recently drew after assessing the evidence for or against this therapy. Now a new review has just been published. Does it change my verdict?

This review evaluated the available literature on the application of oxygen-ozone therapy (OOT) in the treatment of knee osteoarthritis (KOA) to understand its therapeutic potential and to compare it with other conservative treatment options.

Eleven studies involving 858 patients met the inclusion criteria. Patients in the control groups received different treatments:

  • placebo in 1 trial;
  • hyaluronic acid in 2 studies;
  • hyaluronic acid and PRP in 1 trial;
  • corticosteroids in 4;
  • hypertonic dextrose, radiofrequency, or celecoxib + glucosamine in the remaining 3 trials.

The quality of these studies was poor; none of the studies included reached “good quality” standard, 2 were ranked as “fair,” and the rest were considered “poor.” No major complications or serious adverse events were reported following intra-articular OOT, which provided encouraging pain relief at short term. On the basis of the available data, no clear indication emerged from the comparison of OOT with other established treatments for KOA.

The authors concluded that the analysis of the available RCTs on OOT for KOA revealed poor methodologic quality, with most studies flawed by relevant bias, thus severely limiting the possibility of drawing conclusions on the efficacy of OOT compared with other treatments. On the basis of the data available, OOT has, however, proven to be a safe approach with encouraging effects in pain control and functional recovery in the short-middle term.

The use of ozone for treatment of KOA is highly controversial. The mechanism of action of ozone therapy for the treatment of KOA is unclear. Some studies have suggested that ozone injections results in pain relief, reduction of oedema, and improved mobility. The above review might be valuable in summarising the evidence, however, I fing its conclusion odd:

  • The authors write that they cannot arrive at a verdict about efficacy because of the poor quality of the primary studies. I think the conclusion is very clear and should have been expressed bluntly. THE AVAILABLE DATA FAIL TO SHOW EFFICACY; THE THERAPY IS THUS UNPROVEN AND SHOULD THEREFORE NOT BE USED. Simple!
  • I also disagree that OOT was proven to be safe. No treatment can be proven to be safe on the basis of just a few studies. This would require a much, much greater sample size.

This leaves us with the following situation:

  1. OOT is not plausible.
  2. OOT is unproven.
  3. The risks of OOT are unknown.

To me this means that we should stop using it (and I don’t need to change my above-quotes verdict).

According to WebMed, the shark cartilage (tough elastic tissue that provides support, much as bone does) used for medicine comes primarily from sharks caught in the Pacific Ocean. Several types of extracts are made from shark cartilage including squalamine lactate, AE-941, and U-995.

Shark cartilage is most famously used for cancer. Shark cartilage is also used for osteoarthritis, plaque psoriasis, age-related vision loss, wound healing, damage to the retina of the eye due to diabetes, and inflammation of the intestine (enteritis).

A more realistic picture is pained by this abstract:

The promotion of crude shark cartilage extracts as a cure for cancer has contributed to at least two significant negative outcomes: a dramatic decline in shark populations and a diversion of patients from effective cancer treatments. An alleged lack of cancer in sharks constitutes a key justification for its use. Herein, both malignant and benign neoplasms of sharks and their relatives are described, including previously unreported cases from the Registry of Tumors in Lower Animals, and two sharks with two cancers each. Additional justifications for using shark cartilage are illogical extensions of the finding of antiangiogenic and anti-invasive substances in cartilage. Scientific evidence to date supports neither the efficacy of crude cartilage extracts nor the ability of effective components to reach and eradicate cancer cells. The fact that people think shark cartilage consumption can cure cancer illustrates the serious potential impacts of pseudoscience. Although components of shark cartilage may work as a cancer retardant, crude extracts are ineffective. Efficiencies of technology (e.g., fish harvesting), the power of mass media to reach the lay public, and the susceptibility of the public to pseudoscience amplifies the negative impacts of shark cartilage use. To facilitate the use of reason as the basis of public and private decision-making, the evidence-based mechanisms of evaluation used daily by the scientific community should be added to the training of media and governmental professionals. Increased use of logical, collaborative discussion will be necessary to ensure a sustainable future for man and the biosphere.

To be clear: there is no good evidence that the supplements commercially available currently are effective for any condition.

Now, there is more news on this topic:

The objective of this study was to analyse labelling practices and compliance with regulatory standards for shark cartilage supplements sold in the United States. The product labels of 29 commercial shark cartilage supplements were assessed for compliance with U.S. regulations. Claims, including nutrient content, prohibited disease, and nutritional support statements, were examined for compliance and substantiation.

Overall, 48% of the samples had at least one instance of non-compliance with labelling regulations. The most common labelling violations observed were:

  • missing a domestic address/phone number,
  • non-compliant nutrient content claim,
  • missing/incomplete disclaimer,
  • missing statement of identity,
  • prohibited disease claims,
  • incomplete “Supplement Facts” label.

The use of prohibited disease claims and nutritional support statements without the required disclaimer is concerning from a public health standpoint because consumers may delay seeking professional treatment for a disease.

The authors concluded that the results of this study indicate a need for improved labelling compliance among shark cartilage supplements.

In summary, it seems that shark cartilage supplements are bad for all concerned:

  • Patients who rely on them might hasten their death.
  • Sharks are becoming an endangered species.
  • Consumers are being mislead and misinformed.

There is just one party smiling: the supplement manufacturers who make a healthy profit destroying the health of gullible consumers and patients.

Collagen is a fibrillar protein of the conjunctive and connective tissues in the human body, essentially skin, joints, and bones. Due to its abundance in our bodies, its strength and its relation with skin aging, collagen has gained great interest as an oral dietary supplement as well as an ingredient in cosmetics. Collagen fibres get damaged with the pass of time, losing thickness and strength which has been linked to skin aging phenomena. Collagen can be obtained from natural sources such as plants and animals or by recombinant protein production systems. Because of its increased use, the collagen market is worth billions. The question therefore arises: is it worth it?

This 2019 systematic review assessed all available randomized-controlled trials using collagen supplementation for treatment efficacy regarding skin quality, anti-aging benefits, and potential application in medical dermatology. Eleven studies with a total of 805 patients were included. Eight studies used collagen hydrolysate, 2.5g/d to 10g/d, for 8 to 24 weeks, for the treatment of pressure ulcers, xerosis, skin aging, and cellulite. Two studies used collagen tripeptide, 3g/d for 4 to 12 weeks, with notable improvement in skin elasticity and hydration. Lastly, one study using collagen dipeptide suggested anti-aging efficacy is proportionate to collagen dipeptide content.

The authors concluded that preliminary results are promising for the short and long-term use of oral collagen supplements for wound healing and skin aging. Oral collagen supplements also increase skin elasticity, hydration, and dermal collagen density. Collagen supplementation is generally safe with no reported adverse events. Further studies are needed to elucidate medical use in skin barrier diseases such as atopic dermatitis and to determine optimal dosing regimens.

These conclusions are similar to those of a similar but smaller review of 2015 which concluded that the oral supplementation with collagen peptides is efficacious to improve hallmarks of skin aging.

And what about the many other claims that are currently being made for oral collagen?

A 2006 review of collagen for osteoarthritis concluded that a growing body of evidence provides a rationale for the use of collagen hydrolysate for patients with OA. It is hoped that ongoing and future research will clarify how collagen hydrolysate provides its clinical effects and determine which populations are most appropriate for treatment with this supplement. For other indication, the evidence seems less conclusive.

So, what should we make of this collective evidence. My interpretation is that, of course, there are caveats. For instance, most studies are small and not as rigorous as one would hope. But the existing evidence is nevertheless intriguing (and much more compelling than that for most other supplements). Moreover, there seem to be very few adverse effects with oral usage (don’t inject the stuff for cosmetic purposes, as often recommended!). Therefore, I feel that collagen might be one of the few dietary supplements worth keeping an eye on.

Mini-scalpel acupuncture or acupotomy is a relatively new type of non-invasive acupuncture/ micro surgery using a small needle-scalpel invented by Professor Zhu Hanzhang around 30 years ago in China. It is a slightly thicker and more blunt instrument that gets under the skin and is able to break apart adhesions and muscle knots more effectively than a regular acupuncture needle would.

Sounds weird?

Never mind, the question is does it work!

A systematic review showed that almost all studies reported an effect of acupotomy on joint pain compared to a variety of controls. On reflection, this is hardly surprising:

  • all the trials were from China;
  • all had major methodological flaws.

This means that we need better studies to decide the efficacy question.

This new study investigated the efficacy and safety of mini-scalpel acupuncture (MA) for knee osteoarthritis (KOA) in an assessor-blinded randomized controlled pilot trial; this would provide information for a large-scale randomized controlled trial.

Participants (n = 24) were recruited and randomly allocated to the MA group (experimental) or acupuncture group (control). The MA group received treatment once a week for 3 weeks (total of 3 treatments), while the acupuncture group received treatment two times per week for 3 weeks (total of 6 treatments). The primary outcome was pain as assessed by a visual analogue scale (VAS). The secondary outcomes (intensity of current pain, stiffness, and physical function) were assessed using the short-form McGill Pain Questionnaire (SF-MPQ) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Assessments were performed at baseline, 1, 2, and 3 during treatment and at week 5 (2 weeks after the end of treatment).

Of the 24 participants, 23 completed the study. Both groups showed significant improvements in VAS, SF-MPQ, and WOMAC. There were no significant differences between the MA and acupuncture groups. No serious adverse event occurred and blood test results were within normal limits.

The authors concluded that although both MA and acupuncture provide similar effects with regard to pain control in patients with KOA, MA may be more effective in providing pain relief because the same relief was obtained with fewer treatments. A large-scale clinical study is warranted to further clarify these findings.

I can recommend this article to anyone who wants a quick introduction into the critical analysis of clinical trials. It is a veritable treasure trove of mistakes, flaws, errors, fallacies etc. Here are just a few:

  • The authors aim of investigating the safety of MA is unobtainable. It would require not 24 but probably 24 000 patients.
  • The authors aim of investigating the efficacy of MA is equally unobtainable. It would require a much larger sample than 24, a sham control arm, identical treatment schedules, patient-blinding, etc.
  • Calling the trial a ‘pilot’ is endearing but, except for the title and the insufficient sample size, this study has none of the characteristics of a pilot study.
  • In their ‘introduction’, the authors state that miniscalpel acupuncture (MA) is a new subtype of acupuncture that is effective in treating chronic soft tissue injuries such as adhesions and contractures. This is clearly wrong but discloses their bias very plainly.
  • The authors statement that both MA and acupuncture provide similar effects with regard to pain control in patients with KOA is misleading. It implies that both interventions had specific effects. Without a sham control arm, this is pure speculation.
  • Similarly their assumption that MA may be more effective in providing pain relief because the same relief was obtained with fewer treatments, is pure fantasy.
  • In fact, as MA requires injections of local anaesthetics, any outcome is heavily confounded by this addition.
  • In the discussion section, the authors state that because MA is invasive and provides a strong stimulus, some participants complained of stiff and dull pain for few days after treatment. Yet, when reporting adverse effects in the results section, this was not mentioned.
  • The way this study was designed, it should have been clear from the start that it would not produce any meaningful findings. Seen from this perspective, running the trial could even be seen as a breach of research ethics.
  • According to the aims of a pilot study and the authors hope that their study would provide information for a large-scale randomized controlled trial, all reporting of outcomes is misplaced and should be replaced by information as to how a definitive trial should be conducted.

The following footnote is worth mentioning: This study is supported by a grant from the Ministry of Health & Welfare, Korea. It suggests to me that this ministry should urgently re-think its funding strategy and recruit some reviewers who are capable of critical analysis.

In my view, this is a lousy study which the authors decides to call ‘a pilot’ in order to get it published in a lousy journal.

Do musculoskeletal conditions contribute to chronic non-musculoskeletal conditions? The authors of a new paper – inspired by chiropractic thinking, it seems – think so. Their meta-analysis was aimed to investigate whether the most common musculoskeletal conditions, namely neck or back pain or osteoarthritis of the knee or hip, contribute to the development of chronic disease.

The authors searched several electronic databases for cohort studies reporting adjusted estimates of the association between baseline neck or back pain or osteoarthritis of the knee or hip and subsequent diagnosis of a chronic disease (cardiovascular disease , cancer, diabetes, chronic respiratory disease or obesity).

There were 13 cohort studies following 3,086,612 people. In the primary meta-analysis of adjusted estimates, osteoarthritis (n= 8 studies) and back pain (n= 2) were the exposures and cardiovascular disease (n=8), cancer (n= 1) and diabetes (n= 1) were the outcomes. Pooled adjusted estimates from these 10 studies showed that people with a musculoskeletal condition have a 17% increase in the rate of developing a chronic disease compared to people without a musculoskeletal condition.

The authors concluded that musculoskeletal conditions may increase the risk of chronic disease. In particular, osteoarthritis appears to increase the risk of developing cardiovascular disease. Prevention and early

treatment of musculoskeletal conditions and targeting associated chronic disease risk factors in people with long

standing musculoskeletal conditions may play a role in preventing other chronic diseases. However, a greater

understanding about why musculoskeletal conditions may increase the risk of chronic disease is needed.

For the most part, this paper reads as if the authors are trying to establish a causal relationship between musculoskeletal problems and systemic diseases at all costs. Even their aim (to investigate whether the most common musculoskeletal conditions, namely neck or back pain or osteoarthritis of the knee or hip, contribute to the development of chronic disease) clearly points in that direction. And certainly, their conclusion that musculoskeletal conditions may increase the risk of chronic disease confirms this suspicion.

In their discussion, they do concede that causality is not proven: While our review question ultimately sought to assess a causal connection between common musculoskeletal conditions and chronic disease, we cannot draw strong conclusions  due  to  poor  adjustment,  the  analysis methods employed by the included studies, and a lack of studies investigating conditions other than OA and cardiovascular disease…We did not find studies that satisfied all of Bradford Hill’s suggested criteria for casual inference (e.g. none estimated dose–response effects) nor did we find studies that used contemporary causal inference methods for observational data (e.g. a structured identification approach for selection of confounding variables or assessment of the effects of unmeasured or residual confounders. As such, we are unable to infer a strong causal connection between musculoskeletal conditions and chronic diseases.

In all honesty, I would see this a little differently: If their review question ultimately sought to assess a causal connection between common musculoskeletal conditions and chronic disease, it was quite simply daft and unscientific. All they could ever hope is to establish associations. Whether these are causal or not is an entirely different issue which is not answerable on the basis of the data they searched for.

An example might make this clearer: people who have yellow stains on their 2nd and 3rd finger often get lung cancer. The yellow fingers are associated with cancer, yet the link is not causal. The association is due to the fact that smoking stains the fingers and causes cancer. What the authors of this new article seem to suggest is that, if we cut off the stained fingers of smokers, we might reduce the cancer risk. This is clearly silly to the extreme.

So, how might the association between musculoskeletal problems and systemic diseases come about? Of course, the authors might be correct and it might be causal. This would delight chiropractors because DD Palmer, their founding father, said that 95% of all diseases are caused by subluxation of the spine, the rest by subluxations of other joints. But there are several other and more likely explanations for this association. For instance,  many people with a systemic disease might have had subclinical problems for years. These problems would prevent them from pursuing a healthy life-style which, in turn, resulted is musculoskeletal problems. If this is so, musculoskeletal conditions would not increase the risk of chronic disease, but chronic diseases would lead to musculoskeletal problems.

Don’t get me wrong, I am not claiming that this reverse causality is the truth; I am simply saying that it is one of several possibilities that need to be considered. The fact that the authors failed to do so, is remarkable and suggests that they were bent on demonstrating what they put in their conclusion. And that, to me, is an unfailing sign of poor science.

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