The Importance of Convergent Validity
The primary reason (63%) patients go to chiropractors is for the management of low back pain (1). The objective of this publication is to assess the efficacy of chiropractic care for low back pain using an evaluation tool called Convergent Validity.
The denotation of the concept of Convergent Validity has a strict definition. A clinical connotation of the concept of Convergent Validity would include an approach to answering the following question:
How effective is chiropractic care (spinal manipulation)
for the management of low back pain?
There are many ways to approach an answer to such a question. Each research group will construct a particular approach to answer the question. The quality of the research will be assessed by official journal reviewers and journal editors, and if the approach is deemed worthy, the study will be published in a peer reviewed journal.
When a clinician or patient looks at the research, they quickly become aware of the varied approaches to evaluate the question. In different studies, variables often include:
- The year the study was published.
- Country of origin of the researchers and of the patients assessed.
- The journal of publication and the journal’s country of origin.
- The number of subjects in the study.
- The length or duration of the study.
- The methodology of the study, including such categories as randomized controlled trial, randomized clinical trial, an epidemiological study, a prospective study, a retrospective study, etc.
When multiple studies with different methodological parameters, spanning a period of decades, come to the same or similar conclusion, the studies validate each other. This is clinical convergent validity. Below is a review of studies that have appeared to answer the question posed above.
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TITLE: Manipulation in Back Pain
COUNTRY: Canada
JOURNAL: Canadian Medical Association Journal
YEAR: 1958
In 1958, WB Parsons, MD and JDA Cumming, MD published a study to “describe a method of manipulation that for 20 years has brought gratifying results with none of the disasters that so many predict.” This article was published in the Canadian Medical Association Journal, titled (2):
Manipulation in Back Pain
This article was published 66 years ago. The authors made these statements:
“The standard medical treatment for lumbago and other acute backache is bed rest and sedation, counter-irritation and heat, possibly supplemented by massage and injections of procaine.” Yet, “patients soon find that in the majority of instances they can get rapid relief [from spinal manipulation] without the loss of time.”
“The reason we took up manipulation was an interest in backache, with the early discovery that many patients who failed to respond to routine medical treatment went to a manipulator and received immediate relief.”
“Manipulation as an art is as old as medicine.”
“That manipulation will relieve back pain in many instances, few will argue. Those who manipulate swear by it. Those who don’t, condemn it. Those who don’t manipulate warn of all the catastrophes that can result from the practice.”
“That manipulation can bring comfort to mankind there can be no doubt.”
“Since the majority of backaches will respond to manipulation, it is probable that the origin of the pain lies in relationship to one of the joints, either the zygapophysial joint or the intervertebral disc.”
“Pain so severe as to keep the patient in bed is no contraindication to manipulation. We see many patients who are afraid to make an effort to get out of bed but who, following manipulation, get up and move with ease.”
“Much is said about the hazards of manipulation. We do not know what they are.”
“It is our belief, based on long experience, that manipulation is no more beset by hazards than many other recognized procedures in therapy, while its results are often more dramatic and sure.”
“In our hands this approach to backache has proved most gratifying and, more important, has brought comfort to a large group of patients who have not been able to achieve it before.”
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TITLE: Low Back Pain and Pain Resulting from Lumbar Spine Conditions: A Comparison of Treatment Results
COUNTRY: Australia
JOURNAL: The Australian Journal of Physiotherapy
YEAR: 1969
In 1969, Brian C. Edwards, MAPA (Medical Affairs Professionals of Australia), published a study in the Australian Journal of Physiotherapy, titled (3):
Low Back Pain and Pain Resulting from Lumbar Spine Conditions:
A Comparison of Treatment Results
This was the first study to compare the results of effectiveness for low back and leg pain treated with mobilization/manipulation compared to those treated with heat, massage, and exercise. The study used 184 subjects, half were treated with heat/massage/exercise and half were treated with mobilization/manipulation. The authors made these statements:
“The difference in the number of patients with ‘acceptable’ results by each method of treatment, in the third [pain radiation down thigh to knee] and fourth [pain radiation down leg to foot] groups are statistically significant.”
“[The results] indicate that treatment of low back pain and pain resulting from low back conditions by passive movement techniques of mobilization and manipulation is a more satisfactory method than by standard physiotherapy of heat massage and exercise, in regards to both results and number of treatments required.”
“The survey also indicated that by using techniques of mobilization good results can be obtained with patients even if neurological signs are present.”
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This study (3) was reviewed in the 1990 reference text, White and Panjabi’s Clinical Biomechanics of the Spine. Dr. White, MD, is from Harvard; Dr. Panjabi, PhD, is from Yale. They made the following statements (4):
“A well-designed, well executed, and well-analyzed study.”
In the group with central low back pain only, “the results were acceptable in 83% for both treatments. However, they were achieved with spinal manipulation using about one-half the number of treatments that were needed for heat, massage, and exercise.”
In the group with pain radiating into the buttock, “the results were slightly better with manipulation, and again they were achieved with about half as many treatments.”
In the groups with pain radiation to the knee and/or to the foot, “the manipulation therapy was statistically significantly better,” and in the group with pain radiating to the foot, “the manipulative therapy is significantly better.”
“This study certainly supports the efficacy of spinal manipulative therapy in comparison with heat, massage, and exercise. The results (80 – 95% satisfactory) are impressive in comparison with any form of therapy.”
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TITLE: Spinal Manipulation in the Treatment of Low Back Pain
COUNTRY: Canada
JOURNAL: Canadian Family Physician
YEAR: 1985
In 1985, W. H. Kirkaldy-Willis, MD, and J. D. Cassidy, DC, published a study in the journal Canadian Family Physician, titled (5):
Spinal Manipulation in the Treatment of Low Back Pain
Dr. Kirkaldy-Willis was a Professor Emeritus of Orthopedics and director of the Low-Back Pain Clinic at the University Hospital, Saskatoon, Canada.
The authors note that spinal manipulation is one of the oldest forms of therapy for back pain, yet it has mostly been practiced outside of the medical profession. They also note that “there has been an escalation of clinical and basic science research on manipulative therapy, which has shown that there is a scientific basis for the treatment of back pain by manipulation.” The authors made these statements:
“Spinal manipulation is essentially an assisted passive motion applied to the spinal apophyseal and sacroiliac joints.”
“[Joint manipulation] requires precise positioning of the joint at the end of the passive range of motion and the proper degree of force to overcome joint coaptation.”
“With experience, the manipulator can be very specific in selecting the spinal level to be manipulated.”
These authors presented the results of a prospective observational study of spinal manipulation in 283 patients with chronic low back and leg pain. All 283 patients in this study had failed prior conservative and/or operative treatment, and they were all totally disabled (“constant severe pain; disability unaffected by treatment”). These patients were given a “two or three week regimen of daily spinal manipulations by an experienced chiropractor.” Eighty-one percent of the patients achieved a good clinical outcome (“symptom-free with no restrictions for work or other activities;” “mild intermittent pain with no restrictions for work or other activities”).
The authors made these statements:
“In most cases of chronic low back pain, there is an initial increase in symptoms after the first few manipulations. In almost all cases, however, this increase in pain is temporary and can be easily controlled by local application of ice.”
“No patients were made worse by the manipulation, yet many experienced an increase in pain during the first week of treatment. Patients undergoing manipulative treatment must therefore be reassured that the initial discomfort is only temporary.”
“Most family practitioners have neither the time nor inclination to master the art of manipulation and will wish to refer their patients to a skilled practitioner of this therapy.”
“The physician who makes use of this [manipulation] resource will provide relief for many back pain patients.”
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TITLE: Low Back Pain of Mechanical Origin: Randomized Comparison of Chiropractic and Hospital Outpatient Treatment
COUNTRY: United Kingdom
JOURNAL: British Medical Journal
YEAR: 1990
In 1990, epidemiologist TW Meade assembled a team that published a study in the British Medical Journal, titled (6):
Low Back Pain of Mechanical Origin:
Randomized Comparison of Chiropractic and Hospital Outpatient Treatment
The objective of this study was to compare chiropractic and hospital outpatient treatment for managing low back pain of mechanical origin. It is a randomized controlled trial that involved 741 patients. Each patient was re-evaluated at weekly intervals for six weeks, at six months, and at one and two years after entry. The authors stated:
“Chiropractic treatment was more effective than hospital outpatient management, mainly for patients with chronic or severe back pain.”
“For patients with low back pain in whom manipulation is not contraindicated, chiropractic almost certainly confers worthwhile, long-term benefit in comparison with hospital outpatient management.”
“The results were also analyzed according to length of the current episode of pain. Those treated by chiropractors improved more than those treated in hospital.”
“The results leave little doubt that chiropractic is more effective than conventional hospital outpatient treatment.”
“The effects of chiropractic seem to be long term, as there was no consistent evidence of a return to pretreatment Oswestry scores during the two years of follow up, whereas those treated in hospital may have begun to deteriorate after six months or a year.”
“Chiropractic was particularly effective in those with fairly intractable pain-that is, those with a history of severe pain.”
“The results from the secondary outcome measures suggest that the advantage of chiropractic starts soon after treatment begins.”
“Patients treated by chiropractors were not only no worse off than those treated in hospital but almost certainly fared considerably better and that they maintained their improvement for at least two years.”
“There is, therefore, economic support for use of chiropractic in low back pain, though the obvious clinical improvement in pain and disability attributable to chiropractic treatment is in itself an adequate reason for considering the use of chiropractic.”
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This significant article generated an editorial comment in a different United Kingdom medical journal, The Lancet, titled (7):
Chiropractors and Low Back Pain
The editors of The Lancet note:
“[The article] showed a strong and clear advantage for patients with chiropractic.”
“The highly significant difference occurred not only at 6 weeks, but also for 1, 2, and even (in 113 patients followed so far) 3 years after treatment.”
“Surprisingly, the difference was seen most strongly in patients with chronic symptoms.”
“Chiropractic treatment should be taken seriously by conventional medicine, which means both doctors and physiotherapists.”
“Physiotherapists need to shake off years of prejudice and take on board the skills that the chiropractors have developed so successfully.”
•••••
In this study (6), the follow-up period was up to 2 years. In 1995, the same authors published a 3-year follow-up on the same group of subjects. It was also published in the British Medical Journal, and titled (8):
Randomised Comparison of Chiropractic and Hospital Outpatient Management for Low Back Pain:
Results from Extended Follow Up
In 1990, the authors “reported greater improvement in patients with low back pain treated by chiropractic compared with those receiving hospital outpatient management.” The authors further stated:
“The beneficial effect of chiropractic on pain was particularly clear.”
“At three years the results confirm the findings of an earlier report that when chiropractic or hospital therapists treat patients with low back pain as they would in day to day practice those treated by chiropractic derive more benefit and long-term satisfaction than those treated by hospitals.”
“The substantial benefit of chiropractic on intensity of pain is evident early on and then persists.”
“The results of our trial show that chiropractic has a valuable part to play in the management of low back pain.”
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TITLE: Chronic Spinal Pain: A Randomized Clinical Trial Comparing Medication, Acupuncture, and Spinal Manipulation
COUNTRY: Australia
JOURNAL: Spine
YEAR: 2003
In 2003, Lynton Giles, DC, PhD and Reinhold Muller, PhD published a study in the journal Spine, titled (9):
Chronic Spinal Pain:
A Randomized Clinical Trial Comparing Medication, Acupuncture, and Spinal Manipulation
The objective of this study was to compare pain medications, needle acupuncture, and chiropractic spinal manipulation for management of chronic spinal pain. It was a randomized controlled clinical trial. Patients were assessed before treatment, and again at 2, 5, and 9 weeks after the beginning of treatment.
In this study, chiropractic manipulation achieved the best overall results. The authors stated:
“High-velocity, low-amplitude thrust spinal manipulation to a joint was performed by a chiropractor at the spinal level of involvement to mobilize the spinal joints.”
“The highest proportion of early (asymptomatic status) recovery was found for manipulation (27.3%), followed by acupuncture (9.4%) and medication (5%).”
“The results of this efficacy study suggest that spinal manipulation, … may be superior to needle acupuncture or medication for the successful treatment of patients with chronic spinal pain syndrome.”
“The significance of the study is that for chronic spinal pain syndromes, it appears that spinal manipulation provided the best overall short-term results, despite the fact that the spinal manipulation group had experienced the longest pretreatment duration of pain.”
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In 2005, these same authors (9) published a 12-month follow-up status of these patients in the Journal of Manipulative and Physiological Therapeutics, titled (10):
Long-Term Follow-up of a Randomized Clinical Trial Assessing the Efficacy of Medication, Acupuncture, and Spinal Manipulation for Chronic Mechanical Spinal Pain Syndromes
In this 1-year follow up, the authors assess the long-term benefits of medication, needle acupuncture, and spinal manipulation in patients with chronic spinal pain syndromes. The authors stated:
“In patients with chronic spinal pain syndromes, spinal manipulation may be the only treatment modality of the assessed regimens that provides broad and significant long-term benefit.”
“The overall results of this extended follow-up efficacy study appears to favor the application of manipulation” which successfully achieved long-term benefits in chronic spinal pain syndrome patients.
“No such benefit could be observed for medication.”
“Spinal manipulation appeared to provide the highest satisfaction.”
“Patients who have chronic mechanical spinal pain syndromes and received spinal manipulation gained significant broad-based beneficial short-term and long-term outcomes.”
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TITLE: Association of Spinal Manipulative Therapy with Clinical Benefit and Harm for Acute Low Back Pain
COUNTRY: United States
JOURNAL: Journal of the American Medical Association
YEAR: 2017
In 2017, Neil Paige, MD, and colleagues, published a study in the Journal of the American Medical Association, titled (11):
Association of Spinal Manipulative Therapy with Clinical Benefit and Harm for Acute Low Back Pain Systematic Review and Meta-analysis
The objective of this article was to systematically review studies of the effectiveness and harms of spinal manipulative therapy for acute low back pain. The authors stated:
“In this systematic review and meta-analysis of 26 randomized clinical trials, spinal manipulative therapy was associated with statistically significant benefits in both pain and function.”
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TITLE: Comparison of Effectiveness of Chiropractic Spinal Manipulation and Conservative Therapy for Low Back Pain
COUNTRY: United Kingdom
JOURNAL: Journal of Orthopedics and Sports Medicine
YEAR: 2023
In 2023, Emmanuel Wong and colleagues published a study in the Journal of Orthopedics and Sports Medicine, titled (12):
Comparison of Effectiveness of Chiropractic Spinal Manipulation and Conservative Therapy for Low Back Pain
The objective of this study was to describe the evidence for the effectiveness of chiropractic spinal manipulation (SMT) in comparison to the conservative intervention on low back pain (LBP). It is a meta-analysis of eight randomized clinical trials (RCTs). The authors stated:
“SMT which is delivered by chiropractors, is a regularly utilized treatment that has consistently excellent effects in terms of pain intensity and functionality.”
“Clinical practice recommendations for patients with acute, subacute, and chronic LBP suggest chiropractic therapy or spinal manipulation as a scientific proof, cost-effective, conservative treatment approach.”
“Spinal manipulation or mobilization is recommended as an effective therapy for acute, subacute, and chronic LBP by four guidelines in total which include National Institute for Health and Care Excellence (NICE), The American College of Physicians Pain Society, European guidelines for chronic LBP, and European guidelines for acute LBP.”
“RCTs have demonstrated that chiropractic care and its signature treatment, spinal manipulation, is an effective conservative care option for patients with LBP.”
“Chiropractic care seems to be more effective than conservative intervention for LBP in reducing pain, increasing range of motion in lumbar spine, improving disability status, and enhancing general health.”
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TITLE: Reduction of Chronic Primary Low Back Pain by Spinal Manipulative Therapy is Accompanied by Decreases in Segmental Mechanical Hyperalgesia and Pain Catastrophizing: A Randomized Placebo-controlled Dual-blind Mixed Experimental Trial
COUNTRY: Canada and Spain
JOURNAL: Journal of Pain
YEAR: 2024
In 2024, Carlos Gevers-Montoro, PhD, and colleagues published a study in the Journal of Pain, titled (13):
Reduction of Chronic Primary Low Back Pain by Spinal Manipulative Therapy is Accompanied by Decreases in Segmental Mechanical Hyperalgesia and Pain Catastrophizing:
A Randomized Placebo-controlled Dual-blind Mixed Experimental Trial
The objective of this study was to investigate the efficacy of spinal manipulative therapy to improve chronic low back pain. It involved 49 individuals with chronic low back pain and 49 controls (placebo group). The authors stated:
“Most clinical practice guidelines recommend spinal manipulative therapy for the management of chronic low back pain.”
“The present study shows that spinal manipulative therapy produces greater pain relief compared with a control intervention that was undistinguishable from spinal manipulative therapy.”
“The present results indicate that spinal manipulative therapy produced a clinically significant reduction of chronic low back pain.”
Summary Comments
When the studies presented here are viewed through the concept of convergent validity, the conclusion is clear: decades of research throughout the world converge to validate the efficacy of chiropractic spinal manipulation for the management of low back pain.
REFERENCES:
- Adams J, Peng W, Cramer H, Sundberg T, Moore C; The Prevalence, Patterns, and Predictors of Chiropractic Use Among US Adults; Results From the 2012 National Health Interview Survey; Spine; December 1, 2017; Vol. 42; No. 23; pp. 1810–1816.
- Parsons WB, Cumming JDA; Manipulation in Back Pain; Canadian Medical Association Journal; July 15, 1958; Vol. 79; pp. 013-109.
- Edwards BC; Low Back Pain and Pain Resulting from Lumbar Spine Conditions: A Comparison of Treatment Results; Australian Journal of Physiotherapy; September 1969; Vol. 15; No. 3; pp. 104-110.
- White AA, Panjabi MM; Clinical Biomechanics of the Spine; Second edition; JB Lippincott Company; 1990.
- Kirkaldy-Willis WH, Cassidy JD; Spinal Manipulation in the Treatment of Low Back Pain; Canadian Family Physician; March 1985; Vol. 31; pp. 535-540.
- Meade TW, Dyer S, Browne W, Townsend J, Frank OA; Low back pain of mechanical origin: Randomized comparison of chiropractic and hospital outpatient treatment; British Medical Journal; Volume 300; June 2, 1990; pp. 1431-7.
- _____; Chiropractors and Low Back Pain; Lancet; July 28, 1990; Vol. 336; p. 220.
- Meade TW, Dyer S, Browne W, Frank OA; Randomised Comparison of Chiropractic and Hospital Outpatient Management for Low Back Pain: Results from Extended Follow Up; British Medical Journal; August 5, 1995; Vol. 311; No. 11; pp. 349-353.
- Giles LGF, Muller R; Chronic Spinal Pain: A Randomized Clinical Trial Comparing Medication, Acupuncture, and Spinal Manipulation; Spine; July 15, 2003; Vol. 28; No. 14; pp. 1490-1502.
- Muller R, Lynton G.F. Giles LGF, DC, PhD; Long-Term Follow-up of a Randomized Clinical Trial Assessing the Efficacy of Medication, Acupuncture, and Spinal Manipulation for Chronic Mechanical Spinal Pain Syndromes; Journal of Manipulative and Physiological Therapeutics; January 2005; Vol. 28; No. 1; pp. 3-11.
- Paige NM, Miake-Lye IM, Suttorp Booth MS, Beroes JM, Mardian AS, Dougherty P, Branson R, Tang B, PT, DPT; Morton SC, PhD; Shekelle PG; Association of Spinal Manipulative Therapy with Clinical Benefit and Harm for Acute Low Back Pain: Systematic Review and Meta-analysis; Journal of the American Medical Association; April 11, 2017; Vol. 317; No. 14; pp. 1451-1460.
- Wong E, Lee WT, Chau C, Cheng HY, Kwok R; Comparison of Effectiveness of Chiropractic Spinal Manipulation and Conservative Therapy for Low Back Pain; Journal of Orthopedics and Sports Medicine; January 3, 2023; Vol. 5; No. 1; pp. 1-8.
- Gevers-Montoro C, Romero-Santiago B, Medina-García I, Larranaga-Arzamendi B, Álvarez-Gálovich L, Ortega-De Mues A, Piché M; Reduction of Chronic Primary Low Back Pain by Spinal Manipulative Therapy is Accompanied by Decreases in Segmental Mechanical Hyperalgesia and Pain Catastrophizing: A Randomized Placebo-controlled Dual-blind Mixed Experimental Trial; The Journal of Pain; August 2024; Vol. 25; No. 8; Article 104500.
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