Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
How to teach statistics for EBM
- Gervase Vernon (21 April 2002)
-
More and better training in EBM wouldn’t come amiss in diagnostic services too
- Giuseppe Giocoli (21 April 2002)
-
Evidence based medicine in editorials
- Hamish McLaren, Glasgow G21 3UW (22 April 2002)
|
|
|||
|
Gervase Vernon, GP Dunmow, Essex cm6 1bh
Send response to journal:
|
Dear Sirs, your editorial struck a cord because because I had the priviledge of giving a lecture and workshop on this subject last week at the 7th London conference on teching and studying EBM. Some of these methods for teaching statistics to the less numerate have been published. There is also a web based discussion group to share these methods which may be joined by e- mailing me at gervase@jth.demon.co.uk, Yours Sincerely, Gervase Vernon Reference; Vernon G and Wheatley G (2001) How to learn and teach statistics for evidence-based medicine. Education for primary care. 12, 308-311 |
|||
|
|
|||
|
Giuseppe Giocoli, GdL EBM Associazione Microbiologi Clinici Italiani Via Farini, 81. 20159 Milano, Italia
Send response to journal:
|
Having been an enthusiastic reader of papers highlihting the evidence basis of clinical diagnosis during last weeks, I’m now given a chance to recall some concepts which in my opinion are most notable. General practioners feel that their time is best used learning pre- appraised evidence than mastery in clinical epidemiology (1). Their skills should be “primarily those of relating the evidence to particular patients and qualitative explanation of the risks and benefits of treatment options”. As a consequence, Woodcock et al. say that “the challenge for those working in evidence based medicine is to provide summaries of the evidence in a variety of formats that reflect the range of skills of users of evidence, using innovative methods of presentation”. Now, as far as the diagnostic field is concerned, “surely no one still believes that the diagnosis (or exclusion) of a disease begins and ends with a germ culture or a PCR test” (2); contemporaneously the evidence-based approach is urging practitioners of diagnostic services (PDSs) to rethink their traditional role in basic sciences, where mechanisms of disease are studied by using instruments that are objective and bias free, for a more definite function in applied research, where observations of phenomena can be biased and probabilities are used to judge the truth (3). The next challenge for PDSs seems to be presenting their results to clinicians in a probabilistic format, varying with different levels of health care. So, plain likelihood ratios could complement laboratory results in a university hospital, to be directly used for post-test odds or probabilities of disease. On the opposite side, new methods of presenting test accuracy are deemed necessary in primary care (4). In other words, an “Accuracy communication”should be implemented for the sake of “conveying test accuracy information in simple, non technical language, to improve GPs ability to estimate disease probabilities correctly”. Just in the same way as the “Risk communication” between clinicians and patients leads to better understanding and better decisions about clinical management (5). For instance, one could turn a positive likelihood ratio of 20 into a picture explaining that a true positive result is twenty times more probable than a false one. In my opinion, all that implies a real and joint commitment by professional societies to popularize EBM in diagnostic services, much stronger than it has been so far. Needs are obviously greater in non- english speaking countries. Giuseppe Giocoli, MD Competing interests: None 1. JD Woodcock, et al. Doctors' knowledge about evidence based medicine terminology (Editorial). BMJ 2002;324: 929-30 2. ST Green. A new specialty of “Infection Medicine”? (Response to K Cartwright and D Jeffries The current crisis in medical microbiology and virology. BMJ 2002;324:S116) 3. RB Haynes. What kind of evidence is it that Evidence-based Medicine advocates want health care providers and consumers to pay attention to? BMC Health Services Research 2002; 2: 3 4. J Steurer et al. Communicating accuracy of tests to general practitioners: a controlled study. BMJ 2002;324:824–6 5. A Edwards et al Explaining risks: turning numerical data into meaningful pictures.BMJ 2002; 324: 827–30 |
|||
|
|
|||
|
Hamish McLaren, Consultant Physician Stobhill Hospital, Glasgow G21 3UW
Send response to journal:
|
Editor-It is ironic that the BMJ should publish an editorial(1) (gently) deploring Australian general practitioners' lack of knowledge about evidence based medicine terminology when you saw fit to print, a month earlier an editorial on the HOPE study(2) where the only evidence cited to support the statement that "...ramipril substantially decreased the risk of stroke and TIA..." is that treatment produced a 32% in relative risk.In fact reference to the original paper (3) in the same edition shows that the absolute risk reduction for all strokes was 1.5% or in other words 66 patients would have to take ramipril for 4.5 years to prevent one stroke-which may or may not be regarded as a clinically significant effect. In a journal like the BMJ which is such a worthy champion of evidence based medicine surely readers have a right to expect that editorials about recent trials should contain a critical appraisal of the evidence rather than acceptance of the, often over-optimistic, relative risk reduction so beloved of cardiovascular researchers and their pharmaceutical sponsors. 1.Woodcock J D, Greenly S, Barton S. Doctors' knowledge about evidence based medicine terminology. BMJ 2002 324:927-8 2. Schrader J, Luders S. Preventing Stroke. BMJ 2002;324:687-8 3.Bosch J, Yusuf S et al Use of ramipril in preventing stroke : double blind randomised trial. BMJ 2002;324:699-702 |
|||