Every prescription is a clinical trial
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《英国医生杂志》
EDITOR—Senn questions whether individual response to treatment is a valid assumption.1 Patients have never responded consistently to treatment, and, additionally, every time a prescription is written (except for identical twins) what effectively begins is a clinical trial with n = 1.
Evidence based medicine or evidence based clinical practice is the judicious application of best current knowledge to the condition and values of each patient.2 It should therefore allow for individualised treatment, which may entail a drug different from the "best" identified after systematic review. Can the gold standard randomised controlled trial really deliver the desired certainty when identifying which patients will respond to the treatment is impossible?
Trials organised by pharmaceutical companies are designed to show the superiority of a company's product over a competitor's to ensure optimum market share, with little thought for the individual patient receiving the drug. Promotion follows to ensure product recognition at the point of "sale." Examination of published study results soon shows that some subjects do much better with the drug that is statistically inferior.
Consider intravenous regional sympathetic block. Systematic review combined with a double blind evaluation has not supported it as an evidence based treatment,3 yet individual patients are reported as deriving notable benefit, which, in this typical case was 18 months' pain relief after two treatments.4 As it remains, however, a useful and valued component of the planned staged approach to the management of chronic regional pain syndrome type 1, many pain clinicians will continue to include it or an equivalent intervention in their armamentarium.5
An additional problem that regularly occurs is the removal from the market of valuable drugs (although often for limited indications) which are effective in, and appropriate for, many individual patients.
Alfred P J Lake, consultant in anaesthesia and pain management
Glan Clwyd Hospital, Rhyl, Clwyd LL18 5UJ apjlake@aol.com
Competing interests: None declared.
References
Senn S. Individual response to treatment: is it a valid assumption? BMJ 2004;329: 966-8. (23 October.)
Muir Gray JA. Evidence based policy making. BMJ 2004;329: 988-9. (30 October.)
Jadad AR, Carroll D, Glynn CJ, McQuay HJ. Intravenous regional sympathetic blockade for pain relief in reflex sympathetic dystrophy: a systematic review and a randomised, double-blind crossover study. J Pain Symptom Manage 1995;10: 13-20.
Vijayan R, Low KH. Pain relief with intravenous regional guanethidine in post-traumatic reflex sympathetic dystrophy? A case report. Med J Malaysia 1993;48: 236-9.
Lake APJ. Intravenous regional sympathetic block: past, present and future? Pain Res Manage 2004;9: 35-7.
Evidence based medicine or evidence based clinical practice is the judicious application of best current knowledge to the condition and values of each patient.2 It should therefore allow for individualised treatment, which may entail a drug different from the "best" identified after systematic review. Can the gold standard randomised controlled trial really deliver the desired certainty when identifying which patients will respond to the treatment is impossible?
Trials organised by pharmaceutical companies are designed to show the superiority of a company's product over a competitor's to ensure optimum market share, with little thought for the individual patient receiving the drug. Promotion follows to ensure product recognition at the point of "sale." Examination of published study results soon shows that some subjects do much better with the drug that is statistically inferior.
Consider intravenous regional sympathetic block. Systematic review combined with a double blind evaluation has not supported it as an evidence based treatment,3 yet individual patients are reported as deriving notable benefit, which, in this typical case was 18 months' pain relief after two treatments.4 As it remains, however, a useful and valued component of the planned staged approach to the management of chronic regional pain syndrome type 1, many pain clinicians will continue to include it or an equivalent intervention in their armamentarium.5
An additional problem that regularly occurs is the removal from the market of valuable drugs (although often for limited indications) which are effective in, and appropriate for, many individual patients.
Alfred P J Lake, consultant in anaesthesia and pain management
Glan Clwyd Hospital, Rhyl, Clwyd LL18 5UJ apjlake@aol.com
Competing interests: None declared.
References
Senn S. Individual response to treatment: is it a valid assumption? BMJ 2004;329: 966-8. (23 October.)
Muir Gray JA. Evidence based policy making. BMJ 2004;329: 988-9. (30 October.)
Jadad AR, Carroll D, Glynn CJ, McQuay HJ. Intravenous regional sympathetic blockade for pain relief in reflex sympathetic dystrophy: a systematic review and a randomised, double-blind crossover study. J Pain Symptom Manage 1995;10: 13-20.
Vijayan R, Low KH. Pain relief with intravenous regional guanethidine in post-traumatic reflex sympathetic dystrophy? A case report. Med J Malaysia 1993;48: 236-9.
Lake APJ. Intravenous regional sympathetic block: past, present and future? Pain Res Manage 2004;9: 35-7.