Pain Information
Ethical Problems In Pain Medicine
Pain Relief is a Fundamental Human Right !!!
Evidence-Based Medicine (EBM)
Definition
- Evidence-based medicine tries to address the question: "What is the evidence to justify any treatment used in clinical practice?
Why is there a need for EBM?
- A variety of problems and issues came together at the end of the 20th century to trigger a movement to prove clinical effectiveness:
- Exponentially expanding body of knowledge
- Unexplained variations in clinical practice
- Ever increasing consumer expectations
- Rapid introduction of new interventions
- Inappropriate use of existing interventions
- Under use of proven therapies
Isolated cases : But my friend has had treatment xyz and he is now much better. That's enough for me.
- Let’s assume a patient seeks help with chronic headaches. A particular intervention is performed and the patient reports reductions in his headaches over a three week period. Surely a successful treatment?!
- Well...Did I mention that our patient also moved house, purchased new eyeglasses, gave up his proofreading job and stopped drinking alcohol?!
A Word of Warning
- EBM can only examine evidence available to the researcher. In other words - there are a significant number of drugs used beyond licence which do work but where the patent has run out. As such the drug manufacturer has no interest in pursuing any more research into the product. To set up a research study properly takes money, commitment and time (often several years from idea conception to writing up the results). However, daily pressures on individual clinicians will prevent taking part or initiating any form of meaningful research in most cases and ultimately we all are left with a paucity of trials, especially into older medications.
- So, what does it mean if any of the EBM sites quote that there is no evidence for a particular intervention / drug ? Indeed, very little. Only that no-one has put in the money and legwork as yet.
- In summary, every patient should read as much as possible about his/her disease and should become the Master of his problem. However, if you as a patient should find anything new / controversial or indeed find evidence against something your GP / Pain physician etc. has recommended : talk to the relevant health professional and come to a consensus what to do. This is what informed consent is all about.
Web Links
- "Best Evidence" a main UK source of reviews of EBM aimed at the general public (indeed a well done web page)
- "National Electronic Library for Health". "Clinical Evidence is freely available to NHS staff, patients and the public in England through the National electronic Library for Health. It provides a regularly updated guide to evidence about the effectiveness of care". Well, that's the advert. When I have tried to access any of the information I was asked for a password and was reminded that indeed for GBP 5.- i was able to access a single topic for 48 hours (as such a pay-for-view-service)
- Bandolier. Unfortunately much of this information is from the 90s and has not been updated recently. Nevertheless a good source of information when combined with modern resources.
Persistent Problems with EBM and Systematic Reviews
Presented by Tony Gin; Chinese University of Hong Kong; Hong Kong at the ANZCA ASM 2007
Evidence based medicine (EBM) was presented initially as a crusade for a new paradigm in the practice of medicine [1]. Some proponents have acknowledged these early mistakes. Haynes [2] writes: “EBM has long since evolved beyond its initial (mis)conception, that EBM might replace traditional medicine. EBM is now attempting to augment rather than replace individual clinical experience and understanding of basic disease mechanisms. EBM must continue to evolve, however, to address a number of issues including scientific underpinnings, moral stance and consequences, and practical matters of dissemination and application”. Other advocates have continued proselytizing with evangelical zeal, discounting any criticism as heresy. In defence of EBM, Strauss and McAlister [3] ignored some of its major problems, labelled other criticisms as misperceptions, and made several irrelevant and incorrect assertions to support their devotion. These same biases are reproduced in the standard text, [Evidence Based Medicine. How to Practice and Teach EBM], that has a cursory page on the limitations of EBM.
There are many critical analyses of the problems with EBM [4.5], and some of the main issues are summarized below.
The EBM definition of evidence is much narrower than that which is assumed in common usage. Evidence based medicine is not the same as medicine based on evidence. The word evidence is being used increasingly to impart authority and credibility. After all, who would admit to making their decisions without evidence, according to some guess, random whim or disproven theory. EBM will use a broad definition of evidence when it suits, but in reality, the “best evidence” is meant to be that identified using epidemiological and biostatistical techniques. None of the critics of EBM suggest that high-quality evidence should be ignored, but it is only one factor to consider when making decisions. Recently, the EBM hierarchy of evidence has been expanded and modified to try and deflect these criticisms. Although other forms of evidence may now be acceptable, the EBM guide still leaves it up to the clinician to use their professional experience and clinical expertise to integrate all these different factors. This was no different from how Medicine was practiced before EBM.
Evidence prepared by EBM is wrong more times that one would expect for what is supposedly the best unbiased evidence. The results of subsequent large trials have disagreed with conclusions from a systematic review and meta-analysis 10-23% of the time [6]. Early studies of a new treatment are usually positive and it can take years before trials with real negative results are included in a review. Even systematic reviews of the same original papers can come to different conclusions. Systematic reviews and meta-analyses can be prepared badly. The Cochrane review of epidural analgesia in labour prepared by the Pregnancy and Childbirth group is biased when evaluated from an anaesthesia and a patient point of view. Expert knowledge is required to assess papers for review, because a meta-analysis of good methodological quality garbage just produces compact garbage.
EBM is not itself evidence based. There is no evidence that EBM improves patient outcomes. Advocates try and evade this problem by arguing that patients have better outcomes if they receive proven effective therapies, but this sidesteps the issue. Advocates also argue that EBM is widely and effectively taught, but again this does not show evidence of efficacy. Many resources are used to support EBM with no evidence to support this expenditure.
The usefulness of applying EBM to individual patients is limited. Information generalized from large studies may not be applicable to the patient at hand. Many uncommon problems will never have high-level evidence. Although this limitation is acknowledged by EBM advocates, no new guide is given on how to integrate available evidence in these situations. The problem is left to the clinician who will decide what to do as he has done so in the past, before the fuss about EBM.
EBM is based on empiricism and is a poor philosophic basis for medicine. EBM elevates empirical evidence to be the most important basis for clinical decision making. Are there alternatives to the evidence of EBM? Clinical decision making is influenced by many factors and empirical evidence is not necessarily the most important or overriding factor. Apart from empirical evidence, experiential evidence, pathophysiological rationale, patient values and preferences, and external factors such as available resources may all have major influences on the decision made [7].
EBM is not a new paradigm for medicine. Occasionally systematic reviews can be a useful tool to assist clinicians in discussing care with patients and making decisions. EBM provides a framework for the non-scientist clinician to integrate research into their clinical practice, and it is an interesting context for teaching biostatistics. Unfortunately, poor EBM and poorly prepared systematic reviews diminish its usefulness. Clinical and scientific expertise is still required to prepare and interpret EBM, just as it will be to practice medicine in the future, with or without EBM.
References for Tony Gin's talk
- Evidence-Based Medicine Working Group. Evidence-based medicine. A new approach to teaching the practice of medicine. JAMA 1992;268(17):2420-5.
- Haynes RB. What kind of evidence is it that Evidence-Based Medicine advocates want health care providers and consumers to pay attention to? BMC Health Serv Res. 2002;2(1):3.
- Straus SE, McAlister FA. Evidence-based medicine: a commentary on common criticisms. CMAJ 2000;163(7):837-41.
- Cohen AM, Stavri PZ, Hersh WR. A categorization and analysis of the criticisms of Evidence-Based Medicine. Int J Med Inform. 2004 Feb;73(1):35-43.
- Little M. 'Better than numbers...' A gentle critique of evidence-based medicine. ANZ J Surg. 2003 Apr;73(4):177-82.
- Ioanndis JPA, Cappelleri JC, Lau J. Issues in comparisons between meta-analyses and large trials. JAMA 1998; 279: 1089–93.
- Tonelli MR. Integrating evidence into clinical practice: an alternative to evidence-based approaches. J Eval Clin Pract 2006;12:248-256.
References
- Chinn S. A simple method for converting an odds ratio to effect size for use in metaanalysis. Stat Med 2000;19:3127-31.
- Deeks J, Altman DG, Bradburn MJ. Statistical methods for examining heterogeneity and combining results from several studies in meta-analysis. In: Egger M, Smith GD, Altman DG, eds. Systematic reviews in health care: meta-analysis in context. London: BMJ Publishing, 2001.
- Fleiss JL. The statistical basis of meta-analysis. Stat Methods Med Res 1993;2:121-45.
- Greenland S. Quantitative methods in the review of epidemiologic literature. Epidemiol Rev 1987;9:1-30.
- L’Abbe KA, Detsky AS, O’Rourke K. Meta-analysis in clinical research. Ann Intern Med 1987;107:224-33.
- Song F, Eastwood AJ, Gilbody S, Duley L, Sutton AJ. Publication and related biases. Health Technol Assess 2000;4:1-115.
- Song F, Sheldon TA, Sutton AJ, Abrams KR, Jones DR. Methods for exploring heterogeneity in meta-analysis. Eval Health Prof 2001;24:126-51.
- Song F. Exploring heterogeneity in meta-analysis: is the L’Abbe plot useful? J Clin Epidemiol 1999;52:725-30.
- Sterne JA, Juni P, Schulz KF, Altman DG, Bartlett C, Egger M. Statistical methods for assessing the influence of study characteristics on treatment effects in ‘metaepidemiological’ research. Stat Med 2002;21:1513-24.
- Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, et al. Meta-analysis of observational studies in Sources of Cancer Pain: a proposal for reporting. JAMA 2000;283:2008-12.
- Thompson SG. Why sources of heterogeneity in meta-analysis should be investigated. BMJ 1994;309:1351-5.
Waiting Times
Extract from the Brief Summary of the Findings of the Canadian Pain Society Wait Times Task Force October 19, 2006
Establishing Acceptable Waiting Times for Treatment of Pain in Canada
Objective 1 was to review the evidence of the impact of waiting for treatment for chronic pain. A systematic review of the medical literature regarding the relationship between waiting times, health status and health outcomes for patients awaiting treatment for chronic pain was conducted. The results of this review of 24 published studies indicate that waits of 6 months or more for treatment of chronic pain are associated with deterioration in health related quality of life and psychological well being including an increase in depression scores.
Objective 2 was to determine the existence of any international wait time benchmarks for treatment of chronic pain along with a review of the research evidence they are based upon. An extensive systematic review of the literature, a survey of international IASP chapters, and key informant interviews revealed no established benchmarks or guidelines are currently available anywhere in the world for acceptable wait times for the treatment of chronic pain.
Conclusions: Wait times of 6 months for treatment of chronic pain are associated with significant deterioration in health related quality of life (HRQL) and psychological well being. It is unknown at what point during the wait time for treatment this deterioration begins and therefore one cannot conclude that there is a safe waiting period.
Recommendations: Measures should be taken to ensure that waitlists for interdisciplinary chronic pain treatment be no longer than 6 months. There is an urgent need for further studies to determine: (a) at what stage HRQL and psychological well being begins to deteriorate while waiting and (b) whether waiting for treatment for chronic pain has an impact on other health outcomes such as functional restoration.