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Alternative Medicine
Chinese herbal medicines in the treatment of acute respiratory infections: a review of randomised and controlled clinical trials
Chaoying Liu and Robert M Douglas
MJA 1998; 169: 579-582
For editorial comment see Hensley & Gibson
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| Abstract | |||
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Objective: To review clinical trials of Chinese
herbal medicines (CHMs) in the management of acute respiratory
infections (ARIs). Data sources: MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, the Cochrane Library and three Chinese medical journals available in Australia. Study selection: Studies in which a control group was used in comparing CHMs with a placebo or "Western medicine" (usually antibiotics) for treating ARIs were included. Data synthesis: 27 of 46 studies identified in the search of the databases and the Chinese journals fulfilled the inclusion criteria. Twenty-six of these were published in Chinese, and one in English. Twenty were randomised controlled trials and seven were "controlled clinical trials". Although most of the studies reported that CHMs are better than antibiotics for the treatment of ARIs, the quality of the studies was generally poor when evaluated for patient allocation, treatment description, outcome measurement and data analysis. Conclusions: Because the trial methodology of these studies was often inadequate or insufficiently documented, it is difficult to recommend the use of CHMs in ARIs. However, Shuang Huang Lian does appear to be useful for treating lower respiratory tract infections. More rigorous evaluation of CHMs is needed, as they are becoming popular treatments in many countries, including Australia. | |||
| Introduction | |||
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Acute respiratory infection (ARI) is the most common illness in
childhood and is the leading cause of death in children younger than
five years.1,2 In Western medicine,
although ARIs are most commonly caused by viral infection,
antibiotic agents are widely used in their treatment, despite
evidence that the clinical benefits of antibiotics may be
slight.3-5 In China, many physicians
believe that traditional agents are effective in alleviating
symptoms of ARIs, shortening the course of disease, helping recovery
from severe illness, and minimising potential long term
consequences of lung infections (Box 1).6-8 Chinese herbal medicines
(CHMs) are not only routinely used for most respiratory ailments in
hospitals in China, but are also commonly used by many Chinese people
in the community.
The effort to integrate Western and traditional approaches has resulted in a number of publications comparing the benefits of CHMs with Western medicine. Our aim was examine the available evidence in order to explore the generalisability of the traditional Chinese approach to clinical management and determine whether CHMs might be advocated in Australia, where CHMs are now widely marketed.9
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| Methods |
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| Data extraction |
MEDLINE (1966 to May 1997), the Cumulative Index to Nursing and Allied
Health Literature (1982 to May 1997) and the Cochrane Library
(1995 to May 1997) were searched for all studies in which CHMs were
used to treat ARIs. We also performed a search of three Chinese
publications available in Australia: Chung Kuo Chung Hsi I Chieh
Ho Tsa Chih (the Chinese Journal of Integrated Traditional
and Western Medicine) (1982 to 1996), Chinese
Traditional Patent Medicine (1991 to 1996) and Chung Huo I
Hsueh Tsa Chih (Taipei) (the Chinese Medical Journal of
Taipei) (1986 to 1996).
The search keywords were CHMs and acute respiratory infections (or bronchiolitis, pneumonia or viral infections); random allocation; treatment group/control group; CHMs group/Western medicine group.
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| Inclusion criteria |
Studies were included in our review if they had used a control group to
compare CHMs with a placebo or Western medicine. We assessed the
quality of these studies from four perspectives: patient
allocation, treatment description, outcome assessment, and data
analysis.
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| Results | |||
| Of the 46 studies identified from the search, 27 fulfilled our
inclusion criteria.10-36 Ten studies involved
upper respiratory tract infections (URTI) (Box 2), and 17 involved
lower respiratory tract infections (LRTI) (Box 3). Twenty-six
studies were published in Chinese, and one in English.29 Only the
article written in English was found in the databases.
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| Treatment | Most studies used a herbal tea or patent medicine, although six used parenteral preparations and one study36 used a topical herbal preparation.Treatment duration was three to seven days for URTIs, and more than seven days for LRTIs. The control treatment was antibiotics in 18 studies, antiviral agents in five, symptomatic and supportive therapy in three, and a placebo in one. | ||
| Clinical outcomes |
Various methods of reporting outcome were described; a common
approach was to report an "effect rate" from less effective to
significantly effective. CHMs were reported to have a significantly
higher effect rate in 15 of 22 studies (Box 4). Generally, CHMs were
reported to produce greater improvement in clinical symptoms and
physical signs and a shorter hospital stay.
Five out of seven studies testing Maxingshigangton20-24,28,32 and all studies using Shuang Huang Lian29,31,34 reported better treatment effects on bronchiolitis and pneumonia. | ||
| Assessment of study quality |
We rated only two studies as of high methodological quality. Both
examined the efficacy of intravenous Shuang Huang Lian for
LRTIs.29,34
Patient allocation: Twenty studies reported a randomisation strategy, but only three21,30,35 described the allocation method. Three studies29,30,36 reported using single- or double-blind methods in the study. Treatment description: Most studies provided information about the main herbs included in the formulation, dose, course and treatment approach. Information on safety or side-effects of the herbal medicines tested was provided in only four studies.11,17,23,29 In eight studies11,12,14,16,18,21,23,31 the treatment applied to the control group was not described or was manifestly not identical to that of the experimental group in manner of administration. Outcome assessment: Twenty-two studies used a rate to assess the outcome. Eight of these14,15,19,22,23,28,30,36 did not provide adequate information on what constituted the degree of effect or on the defined time point for outcome measures. Satisfactory outcome measures were identified in only eight studies.11,12,22,26,27,29,32,34 Data analysis: Thirteen studies reported baseline data about the participants; only one29 tabled the baseline comparison. Six studies11,17,20,21,29,34 presented statistical results such as mean and standard deviation. Two studies18,28 drew a conclusion regarding efficacy without any reference to statistical analysis.
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| Discussion |
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Although CHMs are the subject of many Chinese research publications,
definitive conclusions about their efficacy are difficult to draw.
There are perceived ethical constraints about conducting rigorous
randomised controlled trials in China, and placebo and double-blind
methods are not generally accepted in clinical research, especially
for time-honoured and widely used treatments. The inadequate
methods of most studies make it difficult to transfer the Chinese
confidence in CHMs to other settings. In the articles we reviewed,
there was insufficient information on randomisation and baseline
comparisons, outcome measures were either complicated or of
doubtful validity, and terms were poorly defined or explained. Data
analysis and presentation were generally too limited to enable us to
assess the adequacy of the statistical analysis. Most of the studies
failed to deal with potential confounding factors, and for several
reports the timing of outcome measures was inappropriate.
Nevertheless, in Chinese practice these traditional approaches are seen as appropriate treatment for ARIs. They are often used as life-saving remedies in preference to antibiotics. From this review, we have been impressed by the "clinical effects" of Maxingshigantong and intravenous Shuang Huang Lian for treating bronchiolitis and pneumonia. On the evidence provided, Shuang Huang Lian appears to be a promising remedy worthy of further study. Interestingly, no studies evaluated the herbs and formulas most widely used in the community for treating the common cold and other common URT infections in China. Perhaps the most widely used herbal medicines, such as Banlangen Chong Ji (tea) and Ganmaoqingre Chong Ji, are so firmly trusted by both clinicians and the community that evaluation is not considered necessary. The one trial published in English was carried out collaboratively between the University of Newcastle, Australia, and the Harbin Medical University, China, and used rigorous procedures to conclude that bronchiolitis was better treated with Shuang Huang Lian than with antibiotics.29 More studies of this calibre are needed. In our view, the scientific evidence that CHMs are more effective than antibiotics in ARIs is inadequate. Our analysis indicates the need for more rigorous evaluation of CHMs, including descriptions of their derivation, preparation, standardisation, potency, safety, and efficacy, if they are to meet modern Western criteria for their use. We suggest that, acknowledging the difficulty in conducting randomised controlled trials in China, the following approaches may be needed:
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| References | |||
* Title translated by C L. (Received 24 Feb, accepted 23 Jul, 1998)
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| Authors' details
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National Centre for Epidemiology and Population Health, The
Australian National University, Canberra, ACT.
Chaoying Liu, MB BS, PhD, Visiting Fellow; Robert M Douglas, MB BS, MD, Director.
Reprints will not be available from the authors. ©MJA 1998 | |||
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