PICO is big when
searching the literature
Evidence-based practice is a
combination of the judicious use of the best external evidence, doctor’s
expertise and patient’s wishes and desires.
External evidence means retrieving and evaluating published scientific
studies. The first part in finding
the evidence is to formulate a searchable question that one will use when
searching an appropriate database.
What question one constructs depends on if
one is searching for what Sackett et al (1) call “background” information or
“foreground” information. Background
information is general information about a condition.
Background questions are more common when one is newer in practice.
However, there are always times throughout a professional career where
background information is needed. For
example, a patient reports that they were just diagnosed with Gaucher’s
Disease and of the innumerable conditions that one learns in chiropractic
college this is one whose details may not be readily available and demands a
background question.
A background question has two basic parts:
1. Who, what, where, when,
how,
or why and a verb. 2.
The disorder or some aspect of it. Using
the Gaucher’s Disease example, an appropriate background question might be:
What effect does Gaucher’s Disease have upon the joints?
Or what treatments are typically used with Gaucher’s Disease?
“Foreground” information is more
detailed information that should inform ones clinical decisions.
Generally, as one is in practice a longer time the greater the percentage
of questions one will search will be of the foreground type.
A foreground question for the example above might be: For a 50 year old
female with Gaucher’s Disease is chiropractic manipulation a better treatment
for the alleviation of joint pain than NSAIDs?
Questions of this type, foreground
questions, are commonly comprised of four parts.
We are reminded of the four parts of a foreground question with the
acronym PICO. PICO stands for
Patient, Intervention, Comparison and Outcome.
P - Patient
The question should start with some general
information about the type of patient. How
detailed the description of the patient needs to be is dependent upon the amount
of literature there is on the intervention in question.
Thus, a very well researched condition or diagnostic method might mandate
one define the patient’s gender, age group, or occupation.
For example if one were searching about spondylolysis in an adolescent
athlete, one would want to include details such as, adolescent and athlete when
constructing the searchable question.
I - Intervention
The most obvious meaning of
intervention is a treatment. However,
for the purposes of asking a searchable clinical question there is also a much
broader meaning for this word. Intervention
can mean diagnostic test, prognostic factor, a patient perception even the
exposure to some environmental factor.
C - Comparison (if
relevant)
The comparison is an alternative
intervention. Keep in mind that one
does not always need to have a comparison intervention in mind when developing a
searchable question. Examples might
be to compare the diagnostic utility of MRI vs.
SPECT in diagnosing a femoral stress fracture.
O - Outcome
The outcome is what one wants the
intervention to do. Obviously when
the intervention is a diagnosis the outcome is about the reliability or validity
of the test. With prognosis or
treatment as the intervention,
the outcome would be some specific morbidity.
Examples of PICO style clinical questions -
with the part of PICO in parentheses
1. In
adolescent athletes with spondylolysis (P) does rest for six weeks (I) reduce
SPECT hot spots (O)?
2. In
adults with whiplash associated disorder (P) does the timing of initial
symptoms (I) predict prognosis (O)?
3. In
athletes (P) does stretching (I) in preventing athletic injuries (O)?
4. In
adults with neck pain (P) does manipulation alone (I) or manipulation combined
with exercise (C) result greater long as a reduction in pain (O)?
Finding Searchable Clinical Questions
Given both the continual advancement of the
scientific knowledge base and everyone’s entropy of knowledge the reality of
clinical practice is that there are more stimuli for searchable clinical
questions than one ever has the time of the actually search.
In fact, there may be so many questions that we come to just accept our
current knowledge as is and have suppressed
the urge we had as students to actually ask the question.
But continual clinical improvement means one needs to create these
questions and I believe in particular question those “facts” we are most
certain of. A good example of the
later is the importance of stretching in preventing athletic injuries.
Systematic reviews (2, 3) have consistently found that stretching on the
average is ineffective in preventing injuries.
In particular areas where questions arise
are the following:
1. Looking
for the etiology of disorders
2. What
the meaning of clinical findings are
3. Determining
the validity and reliability of diagnostic tests
4. What
are the clinical manifestations of a disorder
5. Determining
the likely differential diagnoses
6. How
to estimate a prognosis.
7. Determing
what is the best course of treatment
8. Finding
out how to prevent significant disease or recurrence of a disorder just
treated.
9. Finally,
self improvement. How to keep up
to date and improve ones clinical skills.
1.
Sackett DL,
Straus SE, Richardson WS, Rosenberg W, Haynes RB. Evidence-based medicine:
How to practice and teach ebm. 2nd ed. New York: Churchill Livingstone;
2000.
2. Herbert
RD, Gabriel M. Effects of stretching before and after exercising on muscle
soreness and risk of injury: Systematic review. Bmj 2002;325(7362):468.
3. Weldon
SM, Hill RH. The efficacy of stretching for prevention of exercise-related
injury: A systematic review of the literature. Man Ther 2003;8(3):141-50.
Hypersensitivity in Chronic Pain
Banic
B, Petersen-Felix S, Andersen OK, Radanov BP, Villiger PM, Arendt-Nielsen L, et
al. Evidence for spinal cord hypersensitivity in chronic pain after whiplash
injury and in fibromyalgia. Pain 2004;107(1-2):7-15.
Previous
research has suggested that cases with chronic pain have essentially mediated
hypersensitivity. The problem with
this type of research is that it is based on patience’s subjective assessment
of pain levels. Banic et al. have
conducted an interesting experiment to test, in an objective way, whether
chronic pain patients have spinal cord hypersensitivity sensitivity.
This study uses a procedure involving what is called nociceptive
withdrawal reflex, which is a spinal reflex in the lower extremity that can be
elicited by stimulation of sensory nerves. The
reflex is measured by determining the minimal intensity of the stimulus that is
needed to elicit the reflex which is measured by the evoked potential in the
biceps femoris using EMG. This
method can be used an electrophysiological measure of
the excitability of spinal neurons.
The
study is a sample of people with chronic neck pain after whiplash and
fibromyalgia patients. The
conditions were selected because the pains involved were not specific to the
area tested. In fact those with neck pain obviously did not have
pain in the leg.
The
study found that there was hypersensitivity in spinal cord from stimulation in
the leg even though the whiplash patients did not have leg pain, although the
fibromyalgia patients may have. The
authors contend that since there is spinal cord hypersensitivity in these two
very different pain syndromes that it is likely that spinal cord
hypersensitivity may be seen in other musculoskeletal pain states.
Studies
in animals have shown that tissue damage induces plasticity in the spinal cord
which results in hypersensitivity to peripheral stimulation.
This might explain why the hypersensitivity occurred in their subjects.
Especially given the fact that the injured tissues were distant from the
site of pain. From animal studies it
is known that inflammation producing cyclooxygenase in the spinal cord
ultimately leads to spinal hyperexcitability.
Interestingly, the cyclooxygenase is not localized to the area in the
cord near the injury.
The
importance of the study is that it
provides
evidence that people who have chronic pain may have hypersensitivity to pain
elsewhere in the body. The major
problem with the study is that it is possible for malingerers to use the
knowledge obtained from the study to imply greater impairment.
On the other hand, the nociceptive withdrawal reflex if it is used in
clinical practice can confirm that the patient has cord hyperexcitability and
thus probably is suffering from a chronic pain syndrome.
1. Sackett DL, Straus SE, Richardson WS,
Rosenberg W, Haynes RB. Evidence-based medicine: How to practice and teach
ebm. 2nd ed. New York: Churchill Livingstone; 2000.
2. Herbert RD, Gabriel M. Effects of
stretching before and after exercising on muscle soreness and risk of
injury: Systematic review. Bmj 2002;325(7362):468.
3. Weldon SM, Hill RH. The efficacy of
stretching for prevention of exercise-related injury: A systematic review of
the literature. Man Ther 2003;8(3):141-50.
Whiplash
Sterling
M, Kenardy J, Jull G, Vicenzino B. The development of psychological changes
following whiplash injury. Pain 2003;106(3):481-9.
There
have been various theories suggested about psychological impact of whiplash.
Given our knowledge of fear avoidance beliefs in chronic lower back pain,
it is reasonable to assume a similar process occurs in whiplash.
However to date there are no data that document this.
Sterling
et al in this prospective study have attempted to determine what the
psychological sequella of whiplash
are. Subjects in this study were
stratified after the fact into three groups those that recovered, those with
mild continuing symptoms and those with moderate to severe continuing symptoms.
At intake, two months, three months and six months post injury the
following psychological instruments were used: the General Health Questionnaire
28 (which is used to measure emotional distress), the TAMPA Scale of Kinesphobia
(which is used to measure fear of reinjury due to movement),
the Impact of Events Scale (which is used to measure current stress
related to a specific life events) and SF 36 (measuring general health).
The Neck Disability Index (NDI) and Visual Analog Scale (VAS) were used
to determine the degree of symptoms associated with the whiplash.
The
study found that despite the patient’s outcome, all subjects exhibited some
degree of psychological distress. However,
in all measures but the TAMPA scale the moderate to severe group had higher
scores at intake. This is an
interesting finding as the degree of fear avoidance is not necessarily related
to the severity of the condition at discharge.
Thus neck pain patients did not exhibit the same type of fear avoidance
behaviors as seen in low back pain patients.
Further,
psychological distress decreased in all whiplash groups over the course of the
study. The moderate to severe group,
however, maintained and normal scores on that he GHQ 28 and SF 36 at the
conclusion of the study. In addition
this group is the only group which showed elevated scores on IES questionnaire.
And elevated IES score suggests some measure of post-traumatic stress
disorder. Although these patients do
exhibit stress disorder, it does decrease as their condition improves.
The
results of the study suggest that psychological consult might be advantageous in
patients with whiplash associated disorders early in the treatment as there is
no good prognostic indicator of the eventual development of stress disorders.
Back
Pain Trends
Costs and Utilization
Luo
X, Pietrobon R, Sun SX, Liu GG, Hey L. Estimates and patterns of direct health
care expenditures among individuals with back pain in the United States. Spine
2004;29(1):79-86.
Feuerstein
M, Marcus SC, Huang GD. National trends in nonoperative care for nonspecific
back pain. Spine J 2004;4(1):56‑63.
Lou
et al noted that the previous estimates of costs for back pain are traced back
to data from 1977 in 1984 and 1994 adjusted estimates were made based on this
1977 data. Thus, the validity of
these estimates is dependent on the assumptions made in making the estimates.
Hence, this 1998 data are the most current available to determine cost of
back pain to the U.S. economy. With
total health care expenditures reaching $1.2 trillion and accounting for 13.6 of
the gross domestic product, understanding the proportion of this astronomical
sum that comes from back pain is important for health policy decisions.
Both
of these studies use the 1998 Medical Expenditure Panel Survey (MEPS). MEPS is a
survey conducted by AHRQ investigating various aspects of healthcare
expenditures. There were a total of
32,636 participants in the study, of those 2,120 reported back pain sometime
during 1998. Given the fact that
this is a sampling survey these individuals ultimately represent a sample of
25.9 million adults having back pain in United States in 1998.
Lou
et al identified individuals with back pain by looking for ICD 9 codes.
The codes included more than 720, 721, 722, 723,724, 805, 806, 839, 846,
and 847. Feuerstein et al back pain
was defined as those having ICD codes 724, 846 and 847.
This difference and the definition of what back pain is a may account for
some of the startling findings found in Feuerstein et al.
Feuerstein
et al compared data from this 1998 MEPS survey to 1987 data from the National
Medical Expenditure Survey (NMES). The
startling findings of this comparison are many in particular for doctors of
chiropractic there was a significant decrease in percent of patients using
chiropractic care over this decade. In
1987 40.5% of respondents used
chiropractic care, while in 1997 the chiropractic utilization decreased to
30.6%! Feuerstein et al noted these
are surprising results given the fact that previous studies shown that there are
higher levels of patient satisfaction associate with chiropractic care and
compared to allopathic care.
Additionally, a recent survey showed that over 50% of those surveyed
found chiropractic treatment “very helpful” for low back pain.
The authors suggest that these findings mean that patient perception of
effectiveness is not the contributor to the observed decline in chiropractic
utilization. Other reasons suggested
for the decrease in chiropractic care is an increased perception by physicians,
health care organizations and patients that physical therapy is more effective
for the management of nonspecific back pain.
The authors admit that there are other potential reasons for this trend
which cannot be determined from the data presented (e.g, perceived credibility
of providers to employers and carriers, limitations on insurance reimbursement
and various forms of disability
compensation).
With
the decrease in chiropractic use there was a concomitant increase in both the
use of physical therapy and medical doctors in the treatment back pain.
Physical therapy use went from 4.95% in 1987 to 9.33% in 1997.
The vast majority of chiropractic’s market share went to medical
management which went from 63.97% to 73.73 %.
And likewise there is a significant increase in prescription drug use I
going from 2.0% to 3.9%. Increases
were seen in the use of acetaminophen NSAIDs, muscle relaxants,
narcotic analgesics and non narcotic analgesics. The other findings of
interest include the fact that there was a significant decline in utilization of
x-rays in the decade in question from 32.54 % to 21.54%.
On the other hand there was a nonsignificant increase in utilization of
MR/CT during the decade.
Lou
et al found that 25.9 million adults reported back pain sometime 1998.
The most prevalent diagnosis for low back was ICD9 724 which includes
spinal stenosis, lumbago, sciatica and other unspecified back disorders.
This accounted for 59.5% of all diagnoses.
The next most common diagnosis was ICD9 847 (back sprains and strains) at
16.% , 14.2 % for ICD9 722 (disc disorders) and other disorders of the cervical
spine, ICD9 723 with 9.6%. Expenditures
for lower back pain were $3498 compared with $2177 for individuals without back
pain. Thus, back pain suffers had on
average 1.6 times higher expenditures than those without back pain.
As has been determined many times in the past, it is a minority that
accounts for the majority of costs. Outpatient
expenditures for the top 10% accounted for 86.6% of all expenditure, while the
top 25% accounted for 99.6%.
Exercise and LBP
Rainville
J, Hartigan C, Martinez E, Limke J, Jouve C, Finno M. Exercise as a treatment
for chronic low back pain. Spine J 2004;4(1):106-15.
In
reading this paper I wondered how I would comment on it given the breadth of the
review. Ultimately I am left with
little to say other than recommend that everyone obtain a copy of this review.
It should be noted that this is not a systematic review with effect sizes
but appears to be a comprehensive review of the state of knowledge about
exercise and low back pain. The
author’s abstract follows:
Exercise
is a widely prescribed treatment for chronic low back pain, with demonstrated
effectiveness for improving function and work. The goal of this article is to
review several key aspects about the safety and efficacy of exercise that may
help clinicians understand its utility in treating chronic back pain. A
computerized literature search of MEDLINE was conducted using
"exercise," "fitness," "back pain,"
"backache" and "rehabilitation" as search words.
Identified abstracts were scanned, and useful articles were acquired for
further review. Additional references were acquired through the personal
collections of research papers possessed by the authors and by reviewing prior
review articles on this subject. These final papers were scrutinized for data
relevant to the key aspects about exercise covered in this article. For people
with acute, subacute or chronic low back pain, there is no evidence that
exercise increases the risk of additional back problems or work disability. To
the contrary, current medical literature suggests that exercise has either a
neutral effect or may slightly reduce risk of future back injuries. Exercise
can be prescribed for patients with chronic low back pain with three distinct
goals. The first and most obvious goal is to improve or eliminate impairments
in back flexibility and strength, and improve performance of endurance
activities. There is a large body of evidence confirming that this goal can be
accomplished for a majority of patients with chronic low back pain. The second
goal of exercise is to reduce the intensity of back pain. Most studies of
exercise have noted overall reduction in back pain intensity that ranges from
10% to 50% after exercise treatment. The third goal of exercise is to reduce
back pain-related disability through a process of desensitization of fears and
concerns, altering pain attitudes and beliefs and improving affect. The
mechanisms through which exercise can accomplish this goal have been the
subject of substantial research. Exercise is safe for individuals with back
pain, because it does not increase the risk of future back injuries or work
absence. Substantial evidence exists supporting the use of exercise as a
therapeutic tool to improve impairments in back flexibility and strength. Most
studies have observed improvements in global pain ratings after exercise
programs, and many have observed that exercise can lessen the behavioral,
cognitive, affect and disability aspects of back pain syndromes.
Patient Attitudes
Sharma
R, Haas M, Stano M. Patient attitudes, insurance, and other determinants of
self-referral to medical and chiropractic physicians. Am J Public Health
2003;93(12):2111-7.
This
paper is another outstanding piece of health policy research coming out of
Northwestern College of Chiropractic. The
data was obtained from a large-scale study of 2872 patients who self-selected to
one of 14 medical clinics or 51 chiropractic clinics between December 1994 in
June 1996. Various parameters were
analyzed to determine which predict the choice of going to the chiropractor or
medical doctor for care. The regression analysis found those items that are most
predictive of patients choosing care of a chiropractor.
Items of importance are having less pain and disability, and that the
treatment is not paid for by an insurance company.
It appears that patients who do not have insurance are sensitive to the
fact that costs in a chiropractor’s office are generally lower than medical
office. In those who do have
insurance signed chiropractic care more expensive because of policy limits on
chiropractic care. Patients selected chiropractic care if they trust
chiropractors or they did not like prescription medications.
It is interesting note that those who believe that DCs and MDs are
equally skilled in treating the back pain were more likely to seek medical care
than chiropractic care.
Who is a chiropractor?
This
is the 3rd rail question in chiropractic. The
only way to step on the rail and not get electrocuted is if you have more power
than the rail. The World Federation
of Chiropractic, it appears has that power. They have assembled the WFC Task
Force on Identity. The Task Force
has 40 members (34 DCs, 5 lay persons and one student).
They will be meeting late in February to develop a survey instrument to
be sent to DCs worldwide to question them about our identity.
This is not about what we do but about who we are.
Of particular interest at this point in time is the abstract of
Consultation on Identity
“Abstracts
of Previous Relevant Research.” This is a 23 page PDF document with
information about surveys of lay persons and chiropractors conducted in
Australia, Canada, Ireland, Italy, Netherlands, New Zealand, Switzerland, United
Kingdom and USA. In some cases
detailed information about surveys are presented. In general, there is a
discussion of the methods and findings to this document that should be of
interest to all and is available at WFC’s web site.
For more details please go to WFC’s web site www.wfc.org, after you
choose your language, click on the link for Identity Consultation.
CCP
guidelines removed from
the National Guideline Clearinghouse
The
Vertebral subluxation in chiropractic practice (AKA CCP) guidelines have been
removed from the National Guideline Clearinghouse. Both the Mercy and CCP
guidelines were withdrawn because they no longer meet the NGC inclusion criteria
with respect to date. The NGC generally archives guidelines that are over 5
years old.
A
2001 study found the CCP guidelines unsuitable for use in clinical practice,
while the Mercy guidelines were assessed as useable with proviso.
(1)
1. Cates JR, Young DN, Guerriero DJ, et al.
Evaluating the quality of clinical practice guidelines. Journal of
Manipulative and Physiological Therapeutics. 2001;24(3):170-176.
