Foundation for Chiropractic Education and Research
PO Box 4689 Des Moines IA 50306-4689
For Immediate Release: October 14, 1998
Contact: Robin R. Merrifield
P.O. Box 9656
Seattle WA 98109
Phone/Fax: 800-343-0549
New England Journal of Medicine
Publishes Study
on Chiropractic and Low Back Pain:
FCER's Director of Research Responds
FCER Director of Research Anthony Rosner,
Ph.D., Addresses the New England Journal of Medicine Study
on Low Back Pain
Des Moines, Iowa The Cherkin study that has just
appeared in The New England Journal of Medicine (October
8, 1998 issue) and appears to have taken the media by storm is an
inaccurate and unfortunate representation of the patients who
normally seek chiropractic care for low back pain. It
underscores the dangers of generalizing the results of randomized
clinical trials which themselves represent a specialized
application of therapies under restrictions that are not
necessarily indicative of either the actual therapists or
patients whom they see. Worse, its design flaws are so numerous
and serious, as will be summarized below, that its validity is
compromised to the point of misleading the reader from what is
actually shown in the trial.
- Validity of the intervention
One must be aware that several chiropractic techniques are
applicable to the management of low back pain, some of which are
low-force (Logan Basic Technique, Flexion-Distraction, use of a
drop table, or traction). In this trial, only one high-velocity
technique (side-posture) was applied and this may not be equally
effective for all patients (particularly older people).
Furthermore, important ancillary procedures that are intrinsic to
the chiropractic visit appear to have been denied to patients; in
particular, extension exercises were denied and patients most
likely were not given any literature even though these two
options might be considered part of a customary chiropractic
regimen. The implication is that both these elements were only
permitted in the other two arms (educational booklet and McKenzie
method) of the trial reported. In short, chiropractic treatment
in this particular trial appears to be only a pale shadow of the
actual therapy administered to patients in the real world.
The fact that back pain recurrences as reported by the authors
were 50% by the end of the first year and 70% by the end of the
second year confirms this point of view, not only for
chiropractic but for the McKenzie physical therapy modality as
well.
- Characteristics of the Medical Booklet
What was the purpose and what were the details of the arm
of the trial involving the educational booklet? One is left
wondering what form of therapy this is supposed to represent in
real life, and whether any attention (and of what kind) was given
to the patient in addition to this literature. Finally, no
details of any kind are provided as to the presentation and
actual content of the booklet.
- Lack of sufficient attention to patient
expectations
No details are provided as to how patients were polled
regarding their expectations of treatment, how the questioning
was phrased, and whether the instrument was validated. The
consequences of patient expectations have been given inadequate
attention. Once patients were eligible to participate, how many
refused to participate and for what reasons? The percentage of
patients who had prior chiropractic care for low back pain
appears to be substantially lower for those patients in the
chiropractic arm (24%) than for either the McKenzie or medical
booklet cohorts (35% and 40% respectively). Yet the authors
themselves quote from another prominent investigation that
"the British study found the benefits of chiropractic
treatment to be most evident among patients who had previously
been treated by chiropractors, a group presumably favorably
inclined toward chiropractic care." Consequently, one
can easily argue that the patients in the chiropractic cohort
appear to be doomed to diminished outcomes.
Baseline values regarding severity among the three groups
tested appear to create a bias in the outcomes. First, the
chiropractic group shows the highest tendency in percentages of
patients who, due to low back pain and prior to their therapy,
encounter (a) greater than one day of bed rest (35% vs 24% and
22% for the McKenzie and booklet groups respectively), (b) more
than one day of work lost (39% vs 41% and 30% for the McKenzie
and booklet group), and (c) greater than one day of restricted
activity (72% vs 65% and 52% for the McKenzie and booklet
cohorts).
Second, the initial bothersome and Roland-Morris disability
scores of 4 and 7-8 are substantially below the respective values
of 6-7 and 10 which are more frequently observed in trials
involving significant low back pain. This means that any
observed changes are compressed within an artificially narrow
range and that statistical variations become more disruptive.
The effect of both of these aberrations is to compromise the
monitoring of back pain resolution.
- Patient Compliance issues
Sufficient details regarding patient compliance are
lacking. In addition, there would appear to be a wide variance
between the percentage of patients therapists considered to be
the level of compliance (55%) as opposed to what patients in at
least the McKenzie groups have reported (78%). What were the
levels recorded in both the chiropractic and booklet groups?
How, when, and how often was the question posed to study
subjects? Since compliance is closely linked to satisfaction and
has a major bearing on outcomes, this issue cannot be
ignored.
- Lack of convincing or meaningful cost data
There is no way to draw a meaningful conclusion from the cost
data as presented.
Requisite statistics regarding costs are totally
ignored, such that one cannot assess whether costs follow a
normal distribution or are skewed (and to different extents) in
each of the three regarding modalities. Furthermore, it is
incomprehensible that the HMO costs regarding laboratory
services, medications, and radiology should constitute 50% of the
chiropractic bill when the norm within the United States
indicates that about 80% of chiropractic costs are borne within
the therapist s office and 20% are allocated to external
services while precisely the opposite distribution of percentages
is observed in the offices of allopathic physicians.
The grounds for exclusion and symptoms of sciatica were
not provided. In addition, patients attitudes towards provider
groups should have been assessed for inclusion in the trial as
these would have significant impact upon both their compliance
and outcomes.
In summary, the study is a poor representation of therapies as
applied to the live patient in the physician s office. If left
unanswered, these inquiries would appear to be of sufficient
import as to render the data seriously compromised and the study
as a whole unreliable. It would be a grievous error at this
point to accept the study as Gospel and the authors are invited
to respond.
The Foundation for Chiropractic Education and Research (FCER)
is the largest not-for-profit chiropractic organization devoted
solely to the funding and distribution of chiropractic research.
For more information on FCER, please call (800)637-6244.
###
Foundation for Chiropractic Education and Research
PO
Box 4689 Des Moines IA 50306-4689
For Immediate Release: October 14,
1998
Contact: Robin R. Merrifield
P.O. Box 9656
Seattle WA 98109
Phone/Fax: 800-343-0549
New England Journal of Medicine
Publishes Study on Chiropractic and Asthma: FCER s Director of
Research Responds
Des Moines, Iowa The publication of "A
Comparison of Active and Simulated Chiropractic Manipulation as
Adjunctive Treatment for Childhood Asthma" in The New
England Journal of Medicine, prompted the following response
from Anthony L. Rosner, Ph.D., the Director of Research for the
Foundation for Chiropractic Education and Research (FCER).
A casual reading of the Balon and Aker study, published in the
October 8, 1998 issue of The New England Journal of
Medicine suggests that chiropractic spinal manipulation
provides no benefit to patients. What is overlooked are the
facts that the design of the study is such that the outcome is
all but guaranteed in advance and the benefits of chiropractic
manipulation in the management of asthma (suggested in several
previously published case studies and clinical trials) are
obscured and therefore judged to be nonexistent. At a time when
public interest in the application of alternative medicine is
rising, it is regrettable that a study with such deep flaws
should have found its way to the lead position in such a
prominent journal. Major deficiencies of the study are
summarized as follows:
- Lack of validity of the sham procedure
With over 20 commonly used techniques and over 100
procedures overall described for chiropractic, there is a great
deal of controversy as to what constitutes a proper sham or mimic
treatment. Furthermore, with applications to no less than three
regions of the patient (gluteal, scapular, and cranial), there is
high probability that the sham procedure is invasive and overlaps
to a large extent with the maneuvers chosen for the actual
manipulation. The problem is compounded by the fact that nearly
a dozen chiropractors had to be trained to perform such a
procedure with no indication of standardization. The effect of
all of this is to minimize or obscure the therapeutic effect that
might be observed in an actual adjustment.
- Masking of possible effects by medication
The fact that all patients have been medicated may be
necessary from an ethical point of view, but it would be expected
to mask the beneficial effects that might have been observed from
spinal manipulation. The reader must be cognizant of the fact
that the trial reports no benefits in addition to
standard medication.
- Vagueness of interaction with the patient
The nature of personal interaction with the patient is
ill-defined at best, dubious at worst. No indication is given as
to how the practitioner (such as might be seen in the clinic)
interacts with the patient except to administer a satisfaction
questionnaire. This leads to additional intrigues as it is by no
means clear how eligible patients as young as 7 years of age are
to answer questions pertaining to "feeling at ease, the
skill and the ability of the chiropractor, and overall quality of
care."
- Improvements over baseline values in both
treatments
The fact that there were significant improvements by
intervening with the patients is demonstrated by the declines at
2 months and 4 months of both daytime symptom scores and the
number of puffs per day of a beta-antagonist, in addition to
small increases in peak expiratory flow rates and pediatric
quality of life scores in both groups. Such is to suggest that
even in this trial there was significant improvement in
the patients enrolled. What is not clear is which form(s) of
intervention (global and/or manual) elicited responses and
not that contact with the patient in the chiropractor s
office under customary clinical conditions fails to provide
additional benefits in addition to medication in the management
of childhood asthma. It is simply an outmoded concept to assume
that simply the presence or absence of cavitation constitutes the
difference between chiropractic and no treatment.
- Lack of complete representation of global
symptoms
Given the fact that the human diurnal cycle lasts for 24
hours, I am surprised by the lack of data representing
nighttime symptoms. In effect, we have been shown only
half the picture in this study.
This presentation reflects the challenges and problems of
properly designing a clinical trial that involves more than
simply ingesting medications that can fully mask the other forms
of treatment. Practitioners cannot be blinded in the application
of manual therapies, with the result that the authors have relied
upon the patients incorrect answers to validate their ignorance
of the type of treatment applied despite the fact that nuances of
emotion or expectations of the therapist would be expected to be
conveyed to the patient.
What is needed is far more sensitivity to the actual nature of
asthma. Since it is exacerbated by stress by a plausible
mechanism, one would hope in the future to measure suitable
indicators of stress (such as cortisol levels) in assessing the
outcomes of asthma treatments. The chiropractor remains an
ideal candidate for the evaluation of such procedures, and it is
hoped that the current trial appearing in The New England
Journal of Medicine will not be in any way a deterrent to
much-needed future research.
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