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主题:【原创】在医学上什么是证据?送给无知的人们 -- 虽远必诛

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家园 有的医生

说,不管怎么治疗,感冒了都要走完一个过程,吃药只是为了减轻症状。您肯定知道,在国内感冒了去看医生,几乎是百分百要用抗生素的,这是给女儿看病得出的经验。轻微的感冒,我们就不去医院了。严重一点的,去了医院,医生肯定要让打吊瓶,处方不让看,开的口服药在外面的药店里很难买到,只有医院里有。说起来就生气。

家园 有,流感疫苗!

不过,流感是季节性的,流感疫苗也是季节性的。流感病毒经常变异,所以要预防流感,每到流感季节就得重新打流感疫苗。

这个流感疫苗是通得过虽远大夫所说的Review的。

家园 大夫,有点意见阿

对普通感冒的治疗,给出的结论应该都是没有证据证明这些东西有效吧。直接说无效不是那么严谨把。

比如关于大蒜,还是有一个trial是给出了positive的结论的,其他的四个可能相关的trail作者说没有met the inclusion criteria。作者最后的结论好像还是没有足够的证据,正面的证据太单薄。(A single trial suggested that garlic may prevent occurrences of the common cold, but more studies are needed to validate this finding)

家园 placebo的用法大有讲究

我觉得中医在我们的文化背景下,应该发挥它的作用。

前瞻性随机双盲的临床试验得出的有些结论恐怕不能迷信。

家园 关键是费用

作为义务工作者的您,在明知道是安慰剂的时候,收费收费?

作为患者,事后知道了仅仅是安慰剂是否要付费,是否要起诉?

西医用抗生素,中医用汤药治疗普通感冒,都是安慰剂效应的成分比较多。

如果喝白开水,同和汤药一个效果,是否还要喝汤药?浪费患者资源,社会资源?

RCTs 不好,实际生活中不可控因素太多,但是目前没有比RCTs更好。

靠什么知道疗效?一两个患者的经历?一两个大师的心得,一两本两千年前,自己都不知道说的什么的经典?

借鉴的价值比较大,作为证据,太随机。没有普遍指导性。

家园 这个才是严谨

不知道你要没有 critique article, 对医学文献的评估。

文献的质量不在于结果,患者数目,很多试验都是输在起跑线了。

当初的试验设计有问题,再好的控制,结果都没有意义。

比如说患者的选择,要有专业针对性,要有普遍性。选择普通感冒,就要把其他的细菌性感染排出,比如说口腔,鼻腔,中耳,咽喉,肺,支气管等等。

否则得出的有效,就不会针对普通感冒的。

同时要有广泛的代表意义,排除的患者要明确,比如说,排除癌症,脑出血,头面外伤之类。不能说患者仅仅是20-30岁男性。这个没有代表意义。

cochrane reviews 就是对文献的评估,对比。如果高水平的文献相互支持,自然得出正向结论。比如说CPM 对TKJR 的作用,提高关节活动范围没,提高术后功能。

A 2001 review of 160 Cochrane systematic reviews (excluding complementary treatments) in the 1998 database revealed that, according to two readers, 41.3% concluded positive or possibly positive effect, 20% concluded evidence of no effect, 8.1% concluded net harmful effects, and 21.3% of the reviews concluded insufficient evidence.A review of 145 alternative medicine Cochrane reviews using the more up-to-date 2004 database revealed that 38.4% concluded positive effect or possibly positive (12.4%) effect, 4.8% concluded no effect, 0.69% concluded harmful effect, and 56.6% concluded insufficient evidence.

得出正向结论的比例还是不少的。关键是看试验的水平。

不可否认现在低水平的试验太多,为了经费,为了学位很多人,为了试验而试验,胡编乱造。

有人控制终究是好。

如果cochrane 的除不清楚目前效果的结论,或者没有这个题目。

那样您就要自己 critique 了。很多的评估试验的评分标准,也可以自己做。

通宝推:山远空寒,
家园 不付费,哪能充分发挥placebo的效应。

患者的经历,主观感受是灰常灰常重要的。懂行的placebo不起作用吗?好像也有一点。

家园 原来VC 对普通感冒也没用啊,美国这边的医生对普通感冒的

"药方"经常是多喝水,多睡觉,多喝橙汁补充VC.

那个喝橙汁或者直接吃VC片增强人体系统免疫力的说法有道理吗?不懂医学,请大夫指教.

家园 看得出来,科学这个金喇叭不是那么好吹的。

不过大夫你引用的中药治感冒那段,分明是一帮中国人干的嘛!

你单单把那个结论按你自己的想法翻译了一句,有一点不厚道

的意思在里面啊。

Chinese herbal medicines may shorten the symptomatic phase in patients with the common cold.

这句话你怎么不翻译一下呢?你自己不是宣称中药对普通感冒完全无效的吗?这个和那帮人说的无法确认有效并不等价吧。

大家都责备为什么中医们不去吹响那个金喇叭,其实,他们根本就置不起金喇叭啊。

家园 文化就是文化,和医学或科学都没有关系

如果说科学,那应该是没有文化背景的,正所谓科学没有国界。

说道医学,那标准应该是能否治病,就要提出一个检验的方法。

文化/哲学这些东西都是不着边的。

家园 先别着急发表结论,现把英语提高了,再说。

Chinese herbal medicines may shorten the symptomatic phase in patients with the common cold.

找个英语好,看看是否能得出,cure的结论?

家园 估计和中国的英语教学有关系

may 我记得以前学的时候老师解释是“可以”,突然有一天发现是 “可能”。

可见认真学好英语的重要性。

家园 很有关系。有时候,有一定文化社会背景在里面。

包括疗效,甚至疾病的诊断。病人自己感觉不好,你医生断然告诉人家,没问题,根据现在的标准全部正常,回家呆着,该干嘛干嘛。这种是机器医生。

主观感觉有时候没有可检验的标准。不如:癌症疼痛的打分制度,弄出来意义不大。

家园 大夫,你这样就有点不地道啦。

Cure和完全无效之间还有很多合理的等级。反对“完全无效”就表示确认“CURE”吗?看来你的逻辑比你的英语水平差远了!

你引用的那个文献没有具体提到他们如何进行的试验,但是我理解他们的困难是无法设置一个合乎科学要求的试验方法。

the lack of trials of low enough risk of bias, or using a placebo or a drug clearly identified as a control,

您英语好,何妨把那个摘要全文翻译一下,让大家看看,到底有没有证据表明中药对普通感冒完全无效?当然,其他河友出手我也不反对。我把全文附在后面。

Abstract

Background

Chinese medicinal herbs are frequently used to treat the common cold in China. Until now, their efficacy has not been systematically reviewed.

Objectives

To assess the effectiveness and safety of Chinese medicinal herbs for the common cold.

Search strategy

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 2), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register; MEDLINE (1966 to May 2008); EMBASE (1980 to May 2008); AMED (1985 to May 2008); the Chinese Biomedical Database (CBMdisc) (1978 to May 2008); and China National Knowledge Infrastructure (CNKI) (1994 to May 2008).

Selection criteria

Randomised controlled trials (RCTs) studying the efficacy of Chinese medicinal herb(s) for the treatment of the common cold.

Data collection and analysis

Four review authors telephoned the original trial authors of the RCTs identified by our searches to verify the randomisation procedure. Two review authors extracted and analysed data from trials which met the inclusion criteria.

Main results

We found17 studies involving 3212 patients. The methods of 15 studies were at high risk of bias. In only two studies was the risk of bias low. Trials used "positive drugs", of which the efficacy was not known, as controls. Different Chinese herbal preparations were tested in nearly all trials. In only one trial was a Chinese herbal preparation tested twice. In seven trials, six herbal preparations were found to be more effective at enhancing recovery than the control preparations. In the other 10 studies, seven herbal preparations were not shown to be significantly different from the control. One study did not describe the difference between the intervention and control groups.

Authors' conclusions

Chinese herbal medicines may shorten the symptomatic phase in patients with the common cold. However, the lack of trials of low enough risk of bias, or using a placebo or a drug clearly identified as a control, means that we are uncertain enough to be unable to recommend any kind of Chinese medicinal herbs for the common cold.

家园 看来你不但是英文有问题,逻辑也有问题,看文献,太难为你了

1,现在Cochrane reviews 的出的结论是没有药物可以治愈感冒。某些药物可以缓解症状。

你能分清楚治愈cure 和治疗 treat,症状控制,systematic management 之间的区别吗?

不能!

看看这里。链接出处

所以你说治愈同无效之间有很多级别,就是连基本概念都不懂。

现在在探讨:中药能否治好普通感冒。结论是无法治好。

2,

你引用的那个文献没有具体提到他们如何进行的试验,但是我理解他们的困难是无法设置一个合乎科学要求的试验方法。

你对cochrane reviews 太不熟悉了,不适合于看医学文献。

这个是review,回顾别人的实验,不是自己做实验。

the lack of trials of low enough risk of bias, or using a placebo or a drug clearly identified as a control,

是说目前进入回顾的文章,缺乏偏见控制bias,没有用安慰剂对照,或者没有用其他药物对照。

比如说简单的给汤药,然后得出正性的结果,当然不令人信服,这个是EBM的关键,要有安慰剂,或者其他药物对比,否则人家说不吃,或者吃其他药物更好,你无法回答。

这就是目前可以查到的中药治疗感冒的文献的通病。

这下你明白了吗?

3,既然细究结论,不如都贴出来,看看全文不是更好

外链出处

希望你能看得懂。

一共116页,有兴趣的可以打印出来。

这个是关于偏见控制的

Assessment of risk of bias in included studies

We assessed the risk of bias of each trial in terms of generation

of allocation sequence, allocation concealment, blinding, uncompleted

data and selective reporting; and classified themas ’lowrisk’,

’moderate risk’, or ’high risk’ according to the guidelines of the

Cochrane Handbook for Systematic Reviews of Interventions 5.0.0 (

Higgins 2008) and as described in Wu 2007a. There was no disagreement

in this process.

Sequence generation

An adequate approach for generating allocation sequence with a

low risk of selection bias should be by using a random numbers table

or computer software, or other simple randomisationmethods,

for example, coin tossing or card shuffling. We considered a trial

which only mentions ’random’ but does not include a description

of the approach used as a moderate risk of selection bias.

讲的很清楚,自己好好看。

Allocation sequence concealment

Low risk of selection bias: adequate measures to conceal allocation

sequence is defined as the person who generates an allocation

sequence not recruiting the participants, for example, by central

randomisation. Examples of concealing allocation sequences are

using sealed opaque envelopes or storing allocation sequences in

a locked computer.

Moderate risk of selection bias: where concealment of the allocation

sequence is mentioned but the approach used is not reported.

High risk of selection bias: allocation concealment is reported

inadequately, or is not performed at all.

关于盲的控制

Level of blinding

Masking of both the participants and results assessor was considered

as a low risk of performance or/and detection bias.

Single blinding of the results assessor was considered as amoderate

risk of performance or/and detection bias. If single blinding was

performed on the participants but not the results assessor, it was

considered as a high risk of detection bias.

Non-blinding for detection of outcomes includes quality of life

(QoL); adverse events were considered as a high risk of detection

bias. Blinding was not considered necessary for reporting mortality.

结果的评价

Measures of treatment effect

We analysed the data using Review Manager 5 (RevMan 2008).

We compared outcome measures for binary data using risk ratios.

For continuous data, we used the mean difference.We conducted

a pooled analysis for two trials only (Chang 2002; Yu 2005).

入选实验的介绍

Included studies

All 17 included trials used a parallel group design. Four trials (

Chang 2007; Li 1999a; Wang 2008a; Zhang 2008) were multicentre

trials.

A total of 3212 participants were included in the 17 trials, with

numbers of participants in each trial varying from58 to 463. Only

three trials (Chang 2005; Chang 2007; Wang 2008a) mentioned

that the sample size was calculated according to the SFDA’s regulation

about sample size of non-inferiority test studies (that a total

number of 200 participants be included); extra participants were

also included in these trials to avoid possible attrition bias.

Nine trials included children aged from six months to 14 years (

Chen 2004; Li 1998; Liu 2002;Ma 2000; Pan 2000; Song 2004a;

Wang 1998; Yang 2000; Yu 1997). Eight trials included adultsaged from 18 to 65 or 72 years old (Chang 2002; Chang 2005;

Chang 2007; Li 1999a;Wang 2004;Wang 2008a; Yu 2005;Zhang

2008).

Eleven trials included participants according to TCM signs. Nine

trials (Chang 2005; Chang 2007; Chen 2004; Li 1998; Li 1999a;

Ma 2000; Wang 2008a; Yang 2000; Zhang 2008) included patients

with “fever cold”. One trial (Yu 1997) included both “fever

cold” and “chills cold” patients. Three trials (Chang 2002; Wang

2004; Yu 2005) included “chills cold”.Two trials (Pan 2000;Wang

1998) did not sort the patients by TCM signs.

Two trials (Chang 2002; Yu 2005) compared the Chinese herbs

Sanhan Jiere Koufuye and (Fenghan) Biaoshi Ganmao Chongji.

Other trials used different interventions and comparators. These

are listed below:

Yu 1997 comparedCaichenQinreWeixinGuanchangji

with virazole and acetaminophen.

Li 1998 compared Qinwen Keli granule with Kangbingdu

Koufuye.

Wang 1998 compared JianerQinjie YewithQinre Jiedu

Koufuye.

Li 1999a compared Qinkailing injection with Lincomycine.

Ma 2000 compared Shuanghua Penhuji with

Shuanghuanglian Qiwuji.

Pan 2000 compared Xiaoer Reganning with Vitamin C

Yinqiao Chongji.

Yang 2000 compared Huanghu Jiere Daipaoji with

Shiqi Ganmao Daipaoji.

Liu 2002 compared Kangbingdupian with Banlangen

Chongji.

Chen 2004 comparedGegenCenlianweiWanwith Yinqiao

Jiedupian.

Song 2004a compared self-prepared TCM cream with

penicillin or lincomycin.

Wang 2004 compared Sufeng Ganmao Koufuye with

Ganmao Qinre Koufuye.

Chang 2005 compared Jinlian Qinre capsules with Jinlian

Qinre granules; that is the same ingredients in two

different forms. The principle of selecting the control

drug was that its “effect was commonly recognised”. A

double-dummy placebo was used in both arms.

Chang 2007 compared ChaigeQingre granule with Fufang

Shuanghua granule.

Wang 2008a used a double-dummy placebo in both

arms, and compared Yiqing Shuangjie granule and

Chaihuang tablet placebo with Chaihuang tablet, and

compared Yiqing Shuangjie tablet and Caihuang tablet

placebo with Chaihuang tablet.

Zhang 2008 comparedQingyin injectionwithQinkailing

injection

Recovery (expressed as a dichotomous event)was used as a primary

outcome in all trials, except for Pan 2000 and Zhang 2008. Inefficacy

was reported in 15 trials. Fever clearance time was reported in

six trials (Chang 2002; Chang 2005; Li 1998;Wang 1998;Wang

2008a; Yu 1997). The time point at which the temperature started

to abate was reported in four trials (Chang 2005; Li 1998; Wang

1998; Wang 2008a). Six trials (Chang 2002; Chang 2005; Chen

2004; Li 1999a;Wang 2008a; Yu 1997) compared the prevalence

of viral respiratory tract infection by a throat swab culture. Five

trials reported that liver and kidney function tests were carried

out to look for side effects or adverse events (Chang 2002; Chang

2005; Chang 2007; Wang 2008a; Zhang 2008).

Eight trials (Chang 2002; Chang 2005; Chang 2007; Chen

2004; Song 2004a;Wang 2004;Wang 2008a; Yu 2005) evaluated

changes of TCM signs, which included “e feng han” (fear of wind

and cold); “fa re” (fever); “bi sai liu ti” (snuffles and runny nose);

examination of the colour and surface of the tongue; and “mai

xiang” (examining the pulse).

Risk of bias in included studies

Randomisation

Three trials (Chang 2002; Song 2004a; Yang 2000) mentioned

that a random numbers table was used to generate the allocation

sequence. Three trials (Chang 2005; Chang 2007; Wang 2008a)

mentioned that SAS software was used to generate the sequences.

The other 11 trials mentioned “random allocation”, but no description

about which methods were used. After telephoning the

trial authors, we learned that a random numbers table was used

in seven trials (Chen 2004; Li 1998; Liu 2002; Ma 2000; Song

2004a; Yu 1997; Yu 2005). Five trials used computer software (Li

1999a; Pan 2000;Wang 2004; Zhang 2001; Zhang 2008) and one

trial (Wang 1998) used the method of “mo jiu” (drawing straws).

作者结论

A U T H O R S ’ C O N C L U S I O N S

Implications for practice

We could not find a well-designed trial to provide strong evidence

to support

the use of any Chinese traditional herbal medicines for

the treatment of the common cold.

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