本帖最後由 goodcat1111 於 2009-4-9 00:13 編輯
作者：Marlene Busko
出處：WebMD醫學新聞
February 23, 2009 — 新研究認為，針灸的疼痛緩解效果只比假的針灸（或稱為安慰劑針灸）略好。
丹麥哥本哈根Nordic Cochrane Center的研究者對13篇三組研究的大型綜合回顧顯示，以100-mm視覺類比量表評分，安慰劑針灸的緩解疼痛效果為減少10-mm，而實際針灸的減少程度也只多了4-mm（指減少14-mm） 。
作者之一、Asbjorn Hrobjartsson醫師向Medscape Psychiatry表示，我們認為這表示針灸的止痛效果有相當大程度的安慰劑效應。
他表示，實際針灸的效果似乎太小而無法有臨床關聯，且難以從因為未完整雙盲造成的偏見中區別，安慰劑針灸的效果有時相當有效。
這項研究探究針灸治療偏頭痛、骨關節炎、纖維肌痛等的效果，線上發表於1月27日的BMJ。
【分析安慰劑效應】
作者寫道，針灸的作用理論是根據重要的能量－氣－的存在以及體內的經絡，一般相信針灸對於疼痛有重要效果。
不過，回顧之前針灸、安慰劑針灸以及沒有針灸的止痛效果比較，結果各異。
為了分析針灸和安慰劑針灸對疼痛的效果，研究者回顧了13篇臨床試驗，將3,025名病患隨機分成三組：實際針灸、安慰劑針灸或者沒有針灸。此次回顧包括傳統針灸以及電子針灸試驗。至於安慰劑針灸，有7個試驗是在非穴位處表面扎針，有4個試驗則是實際扎入，另外2個試驗則未穿過皮膚。
治療各類疾病相關疼痛病患的試驗分別是大腸鏡檢查(1個試驗)、纖維肌痛(1)、下背痛(3)、偏頭痛(1)、骨關節炎(3)、術後疼痛(2)、疤痛(1)、緊張性頭痛(1)。
所有病患都接受標準照護，一般性止痛劑(13個試驗)或者物理治療(5個試驗)，因此，研究發現侷限於針灸和安慰劑針灸的加成作用。
針灸和安慰劑針灸之間，在疼痛減少程度上有一些不同，安慰劑針灸和沒有針灸之間則有中度差異。
作者寫道，因為普遍將100-mm視覺類比量表上減少10-mm 視為「最小」或「小」改變，此次回顧認為，針灸的止痛效果尚不足以有臨床關聯。
他們指出，病患未完整雙盲、病患與針灸師之間的互動，或許與此觀察發現有部份或整體關聯。
【不是真的安慰劑】
英國普利茅斯大學Exeter校區的Adrian White醫師和皇家倫敦順勢醫療醫院的Mike Cummings醫師在編輯評論中認為，於傳統解剖位置扎針和假針灸之間些微但顯著的不同，可能是因為在兩組活性治療中的生理差異— 傳統穴位扎針在較深的組織，安慰劑組則是在較表面的組織。
White醫師向Medscape Psychiatry表示，安慰劑針灸一般是將針扎在錯誤位置，因此可能也有一些效果— 換句話說，這不是真的安慰劑。
至於安慰劑組視覺類比量表減少10-mm、實際針灸只多減了 4-mm，他表示，不要忘記考量病患，病患的整體效果是減少14-mm ，這相當有價值。
他指出，扎針安慰劑比安慰劑藥丸有更大的效果，這原因尚未完全瞭解。
此次回顧設計於搜尋那些方法類似而非臨床狀況類似的試驗，這不是典型的研究方法。編輯指出，由於此分析涵蓋了各類狀況，無法直接告知某一特定狀況病患之臨床決定。
不過，他們指出，對於肌肉骨骼類狀況，針灸相對於一般照護的整體效果有臨床關聯，特別是考量有限之治療選擇、針灸的安全紀錄與病患偏好時。
White醫師表示，傳統系統性回顧方式探討針灸對於噁心、慢性背痛、膝蓋骨關節炎、術後疼痛、緊張性頭痛等特殊狀況之效果顯示有證據支持。其他回顧認為對其他狀況的效果並無定論，其他則是認為對戒菸或者中風之恢復沒有效果。
回顧作者報告沒有財務宣告。編輯、 White醫師與 Cummings醫師是英國醫療針灸協會的員工，該協會是立案的慈善機構，目標在推廣使用針灸以及以科學角度瞭解針灸的醫療與大眾利益。 White醫師是Acupuncture in Medicine的主編。
BMJ. 線上發表於2009年1月27日。
Acupuncture Has Small Analgesic Effect Compared With Sham Acupuncture
By Marlene Busko
Medscape Medical News
February 23, 2009 — Pain relief with acupuncture is only slightly better than that achieved with sham, or "placebo," acupuncture, new research suggests.
A large, systematic review of 13 three-group studies conducted by investigators at the Nordic Cochrane Center, in Copenhagen, Denmark, showed on a 100-mm visual analog pain scale that the effect of placebo acupuncture corresponded to a 10-mm reduction in pain, while true acupuncture added a further 4-mm reduction.
"We interpret this to mean that the analgesic effect of acupuncture is, to a very large degree, a placebo effect," review author Asbjorn Hrobjartsson, MD, told Medscape Psychiatry.
"The effect of true acupuncture seems to be too small to be of clinical relevance and is difficult to distinguish from bias due to incomplete blinding. The effect of placebo acupuncture seems, at times, to be quite effective," he said.
The study, which looked at acupuncture treatment for clinical conditions ranging from migraine to osteoarthritis to fibromyalgia, was published online January 27 in BMJ.
Parsing Out Placebo Effect
The theory of how acupuncture works is based on the existence of the vital energy Qi and meridians in the body, and acupuncture is commonly believed to have an important effect on pain, the authors write.
However, previous reviews of the analgesic effects of acupuncture vs placebo acupuncture vs no acupuncture or no treatment have reported conflicting results.
To analyze the effect of acupuncture and placebo acupuncture for pain, the researchers reviewed 13 clinical trials of acupuncture that randomized 3025 patients to 3 groups: true acupuncture, placebo acupuncture, or no acupuncture.
The review included trials of traditional acupuncture and electroacupuncture. Placebo acupuncture was done by superficial needling at nontraditional points in 7 trials, by other penetrative needling in 4 trials, and without skin penetration in 2 trials.
The patients were being treated for pain associated with colonoscopy (1 trial), fibromyalgia (1), low back pain (3), migraine (1), osteoarthritis (3), postoperative pain (2), scar pain (1), and tension headache (1).
All patients received standard care, usually analgesics (13 trials) or physiotherapy (5 trials). Thus, the findings are limited to the additive effect of acupuncture and placebo acupuncture.
There was a small difference in pain reduction with acupuncture vs placebo acupuncture and a moderate difference between placebo acupuncture and no acupuncture.
Since a consensus report characterized a 10-mm reduction on a 100-mm visual analog scale as representing "minimal" change or "little change," the findings in this review suggest that the analgesic effect of acupuncture on pain is not sufficient to be clinically relevant, the authors write.
Incomplete blinding of the patients, or the interaction between the patients and the acupuncturists, might explain some or even all of the observed effect, they note.
Not a True Placebo
In an accompanying editorial, Adrian White, MD, from the Universities of Exeter and Plymouth, in Plymouth, the United Kingdom, and Mike Cummings, MD, from the Royal London Homeopathic Hospital, in London, the United Kingdom, suggest that the small but significant difference between needling at classic anatomical locations and sham acupuncture may be due to the physiological difference between 2 active treatments — needling classic points in deeper tissues and incorrect points in more superficial tissues.
"Acupuncture 'placebo' generally involves placing needles in the wrong locations and is therefore likely to have some activity — in other words, this is not a true placebo," Dr. White told Medscape Psychiatry.
Commenting on the 10-mm reduction on the visual analog scale with placebo acupuncture and the further 4-mm reduction with acupuncture, he said: "Don’t forget the patient: the patient gains the total effect, in this case a 14-mm reduction, which is certainly worthwhile."
Needles as a placebo have a greater effect than placebo pills, for some reason that is not fully understood, he added.
The review was designed to search for trials with a similar methodology as opposed to similar clinical condition, which is an "unusual" approach. Therefore, because the analysis covers such a broad range of conditions, "it cannot directly inform clinical decisions about patients with particular conditions," the editorialists note.
Nevertheless, they add, "the overall effect size of acupuncture in relation to usual care may be clinically relevant for musculoskeletal conditions, particularly in view of the limited treatment options and acupuncture’s safety record and patient preference.
"Conventional systematic reviews of acupuncture’s effect on specific conditions provide evidence for an effect in nausea, chronic back pain, knee osteoarthritis, postoperative pain, and tension headache," said Dr. White. "Other reviews are suggestive but not conclusive for an effect in other conditions, and still others suggest no effect on smoking cessation or for stroke recovery," he said.
The review authors report no financial disclosures. The editorialists, Dr. White and Dr. Cummings, are employees of the British Medical Acupuncture Society, a registered charity established to encourage the use and scientific understanding of acupuncture within medicine for the public benefit. Dr. White is editor in chief of Acupuncture in Medicine.
BMJ. Published online January 27, 2009. |
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