17 December 2014

The Clinical Art of Pain Medicine: Balancing Evidence, Experience, Ethics, and Policy

Blackwell Synergy - Pain Medicine, Volume 6 Issue 4 Page 277-279, July 2005 (Full Text)
The Clinical Art of Pain Medicine: Balancing Evidence, Experience, Ethics, and Policy

* Rollin M. Gallagher, MD, MPH

Efficacy, effectiveness, morbidity risks, and costs are four metrics that inform our conscious clinical reasoning about treatment for each patient. These metrics also inform general treatment strategies for different patient groups defined by characteristics such as mechanism, disease, age, comorbidities, and insurance coverage. Physician factors such as bias and values, sometimes unconscious, may also affect clinical reasoning. The Spine Section herein, while arguing best practices for zygapophysial blocks, highlights the importance of carefully considering the source and meaning of our metrics in pain medicine practice.

Efficacy tells us about the chances of pain relief and its expected magnitude from any treatment, based on double-blind, placebo-controlled clinical trials in specific clinical populations. Effectiveness, a less precise metric usually derived from extended open label clinical trials and clinical experience, informs us of the performance of a treatment in a practice setting where factors such as convenience, comorbidities, and tolerability influence our decisions. Tricyclic antidepressants for neuropathic pain or depression are a good example––efficacy is established, but effectiveness in the field, which is enhanced by side-effects such as nighttime sedation and by once-a-day dosing convenience, is limited by both side-effect burden and concerns about toxicity and drug–disease interactions (e.g., arrhythmias, hypotension, urinary retention, suicide). Morbidity risks may emerge in early clinical trials, but sometime only after large populations are exposed to a particular drug or procedure in routine clinical practice over years or in large, postapproval multicenter trials. Nonsteroid anti-inflammatory drug (NSAIDS) (gastrointestinal and renal risk), Cox 2 inhibitors (cardiovascular risk), and spinal surgery for nonspecific low back pain (failed back surgery syndrome) are examples of risks that emerged in the public's awareness long after treatments were widely used in the field. Costs may influence practitioners’ decisions about what to recommend, and patients’ decisions about what prescriptions to fill and what advice to follow. Managed care plans require time-consuming preapproval for many treatments and may sanction physician outliers. Well-insured or wealthy patients often ignore cost, which for others may preclude filling a prescription or using it correctly ("a little is better than none"). As a general rule, when medicine fails to develop cost-effectiveness models for practice, a business model prevails and restricts practice. Business knows that withholding treatment for costs implies an administrative, rather than therapeutic, relationship to the patient, and that this position is uncomfortable for most physicians.

What is our metric for deciding when a procedure is justified for any one patient? Can we weigh the cost-effectiveness of a treatment against our patient's hopes for relief ? If initial treatment is ineffective, when does our own insecurity influence our decisions? When is consultation appropriate? Dr. Schofferman [1] reminds us that conventional wisdom based on extensive research suggests that a two-point reduction in pain on a 0–10 scale is clinically significant and that many investigators consider a 50% improvement to be significant when evaluating efficacy [2]. In our practices we chip away at the pain, using the additive benefit of several modalities to bring the pain down to a level that enables the patient to enjoy a meaningful quality of life. Ultimately, a level 4 may be as low as we can get without intolerable side-effects; if level 4 improves quality of life and achieves a patient's desired goals (if not complete relief, then return to work or other meaningful activity), we consider treatment successful. Complete relief often seems ephemeral in pain clinics for two reasons: first, the "simple" cases with one or a few isolated lesions causing pain that respond to a block or neuroablative procedure may be treated successfully before referral; second, the cases that are referred have more complex pain (multiple mechanisms, including progressive tissue damaging disease or central nervous system damage) or more complex clinical problems (e.g., medical or psychiatric comorbidities). This reality indicates the fundamental problem with our model of sequential care in pain medicine––we often do not see the patient until after a succession of treatment failures by others, and the resulting complications of poor pain relief [3].

Articles by Drs Barnsely [4] and Bogduk [5] in the Spine Section argue another perspective––that only complete relief from pain, no pain, is the gold standard outcome upon which treatments should be judged. Barnsley, in a study of a consecutive sample of patients who underwent neurotomy of the medial branches of the cervical dorsal rami to palliate chronic zygapophysial joint pain, used complete relief of pain as the indicator of successful outcome. This was obtained for 36 of 45 cases (80%) for a mean of 35 weeks and is, indeed, a very impressive result. Although this study is not placebo controlled, the magnitude of effect (complete relief) argues strongly for effectiveness. (A recent study of subanesthetic ketamine in complex regional pain syndrome [6], using a similar metric, similarly argues for the effectiveness of a new treatment in what many have considered a treatment-resistant disease). Bogduk's review of the evidence for the efficacy of steroid injections into lumbar zygapophysial joints uses the same criterion for success. However, his review suggests little more than placebo effect for this procedure when used in the lumbar region.

Schofferman's commentary [1] cogently present a different perspective. He argues that pain specialists, particularly experienced clinicians, often treat outliers, patients that do not conform to the strict selection criteria required in a research protocol. These patients may have several causes of pain and are more likely to have failed conventional treatment and to have comorbidites. He suggests that the clinical art of medicine, informed by but not dictated by evidence-based medicine (EBM), should determine our behavior as clinicians. He also suggests that ethical principles ("do no harm") inform these decisions––that not doing something that might relieve pain, when its potential harm is minimal and the chances of success reasonable, given the available information, is not "best practices."

I agree that practicing the clinical art of pain medicine should be guided by this combination of values (evidence, clinical needs, and ethics) in pain practice (see Dubois M, Pain Medicine 2005;6[3]). We should add to that equation the value of a mindfulness of social policy. This perspective is particularly important for a field engaged now in a struggle to establish its professional authority through EBM and public accountability. The physician caring for a patient with unrelenting pain feels a moral imperative to ease suffering. Some may respond by trying anything that might work. If it is well reimbursed, then, as Dr. Bogduk suggests, our economic "imperative" is satisfied, and we are gratified in testing our clinical skills. Many consider this posture irresponsible, because it jeopardizes our professional standing as a field. A more nuanced approach, recognizing all the factors that might influence outcome, is needed. Trying a procedure as an isolated treatment without addressing a patient's risks for poor outcome is unwise clinically and, to many, unethical because of its cumulative negative effects on social policy as regards our specialty. The ultimate negative outcome would be reducing the public's access to our effective treatments. Although today this behavior may be reimbursed, it reduces our professional authority and makes tomorrow's reimbursement for our effective procedures less likely. The highest clinical art imbeds procedures in a plan that addresses other salient risks, thus improving cost-effectiveness and enhancing our reputation. Ultimately, calm demeanor and reasoned judgment, informed by education, training, experience, ethical principles, and emerging evidence, is the medical product that society will deem invaluable.

1 Schofferman J. Commentary to a narrative review of intra-articular corticosteroid injections for low back pain. Pain Med 2005; 6( 4): 297– 8 .
2 Farrar J, Young J, LaMoreaux L, Werth J, Poole M. Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale. Pain 2001; 94: 149– 58.
3 Gallagher RM. Pain medicine and primary care: A community solution to pain as a public health problem. Med Clin North Am 1999; 83( 5): 555– 85.
4 Barnsley L. Percutaneous radiofrequency neurotomy for chronic neck pain: Outcomes in a series of consecutive patients. Pain Med 2005; 6( 4): 282– 6 .

5 Bogduk N. A narrative review of intra-articular corticosteroid injections for low back pain. Pain Med 2005; 6( 4): 287– 96 .
6 Correll GE, Maleki J, Gracely EJ, Muir JJ, Harbut RE. Subanesthetic ketamine infusion therapy: A restrospective analysis of a novel therapeutic approach to complex regional pain syndrome. Pain Med 2004; 5( 3): 263– 75.

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