Arnold E, Clark C E, Lasserson T J, Wu T
St George's, University of London, Community Health Sciences (6th Floor, Hunter Wing), Cranmer Terrace, Tooting, London, UK, SW17 0RE.
Cochrane Database Syst Rev. 2008 Jan 23(1):CD005989. doi: 10.1002/14651858.CD005989.pub2.
Herb and plant based preparations are a popular treatment for asthma, although there remain concerns as to their efficacy and safety. In Western societies, motivations for using such treatments may be both positive and negative, with their perceived safety and dissatisfaction with conventional medicine among them. In China such treatments are more commonly used and many compounds considered 'conventional' are derived from herbs or plants.
To assess the efficacy and safety of herb and plant extracts in the management of chronic asthma.
The Cochrane Airways Group Trials Register, CENTRAL, MEDLINE, EMBASE and AMED were searched with pre-defined terms. Searches are current as of February 2007.
Randomised placebo controlled trials of any herb or plant extract were eligible. Study participants had to have a primary diagnosis of asthma. Studies in both adults and children were eligible for the review.
Two reviewers assessed studies for suitability. Data were extracted and double-checked.
Twenty-seven studies (29 experimental groups) met the review entry criteria, randomising a total of 1925 participants. The studies identified assessed the effects of 21 different herbal preparations. Study quality varied considerably, and the sample sizes were often small. For primary outcomes (exacerbations, steroids use and lung function measurements): Two out of six studies reporting change in FEV1 were positive, with very few data available on the frequency of exacerbations. One study which did report these data was negative. Health-related quality of life was only measured in one trial.
AUTHORS' CONCLUSIONS: The evidence base for the effects of herbal treatments is hampered by the variety of treatments assessed, poor reporting quality of the studies and lack of available data. The data that are available from the studies provide only a small insight into the long-term efficacy and harm profiles of these treatments. The absence of common endpoint measurements limits the validity of our findings further. Positive findings in this review warrant additional well-designed trials in this area.
草药和植物制剂是治疗哮喘的常用方法，但其疗效和安全性仍存在争议。在西方社会，使用此类疗法的动机可能有积极的也有消极的，其中包括对其安全性的认知以及对传统医学的不满。在中国，此类疗法更为常用，许多被视为“传统”的化合物都源自草药或植物。
评估草药和植物提取物治疗慢性哮喘的疗效和安全性。
使用预定义术语检索Cochrane Airways Group试验注册库、CENTRAL、MEDLINE、EMBASE和AMED。检索截至2007年2月。
任何草药或植物提取物的随机安慰剂对照试验均符合条件。研究参与者必须有哮喘的初步诊断。成人和儿童的研究均符合纳入综述的条件。
两名评价员评估研究的适用性。提取数据并进行二次核对。
27项研究（29个实验组）符合综述纳入标准，共随机分配1925名参与者。纳入的研究评估了21种不同草药制剂的效果。研究质量差异很大，样本量通常较小。对于主要结局（病情加重、类固醇使用和肺功能测量）：报告第1秒用力呼气量（FEV1）变化的6项研究中有2项呈阳性，关于病情加重频率的数据很少。一项报告了这些数据的研究呈阴性。仅在一项试验中测量了与健康相关的生活质量。
评估的治疗方法多样、研究报告质量差以及缺乏可用数据，阻碍了草药治疗效果的证据基础。研究中可用的数据仅能提供对这些治疗方法长期疗效和危害的少量见解。缺乏共同的终点测量进一步限制了我们研究结果的有效性。本综述中的阳性结果需要在该领域进行更多精心设计的试验。
