meta-analysis

Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis.: Lancet Infect Dis. 2007 Jul; 7(7): 473-80 Shah SA, Sander S, White CM, Rinaldi M, Coleman CI

Echinacea is one of the most commonly used herbal products, but controversy exists about its benefit in the prevention and treatment of the common cold. Thus, we did a meta-analysis evaluating the effect of echinacea on the incidence and duration of the common cold. 14 unique studies were included in the meta-analysis. Incidence of the common cold was reported as an odds ratio (OR) with 95% CI, and duration of the common cold was reported as the weighted mean difference (WMD) with 95% CI. Weighted averages and mean differences were calculated by a random-effects model (DerSimonian-Laird methodology). Heterogeneity was assessed by the Q statistic and review of L'Abbé plots, and publication bias was assessed through the Egger weighted regression statistic and visual inspection of funnel plots. Echinacea decreased the odds of developing the common cold by 58% (OR 0.42; 95% CI 0.25-0.71; Q statistic p<0.001) and the duration of a cold by 1.4 days (WMD -1.44, -2.24 to -0.64; p=0.01). Similarly, significant reductions were maintained in subgroup analyses limited to Echinaguard/Echinacin use, concomitant supplement use, method of cold exposure, Jadad scores less than 3, or use of a fixed-effects model. Published evidence supports echinacea's benefit in decreasing the incidence and duration of the common cold.

[Quality appraisal of systematic reviews or meta-analysis on traditional Chinese medicine published in Chinese journals]: Zhongguo Zhong Xi Yi Jie He Za Zhi. 2007 Apr;27(4):306-11 Authors: Liu JP, Xia Y

OBJECTIVE: To critically assess the quality of literature about systematic review or meta-analysis on traditional Chinese medicine (TCM) published in Chinese journals. METHODS: Electronic searches in CNKI, VIP and Wanfang data-base were conducted to retrieve the systematic reviews or meta-analysis reports on TCM, including herbal medicine, needling, acupuncture and moxibustion, as well as integrative medicine, they were identified and extracted according to the 18 items of QUOROM (quality of reporting of meta-analyses) Statement and relative information. The appraisal was made taking the indexes mainly including objectives, source of data, methods of data extraction, quality assessment of the included studies, measurement data synthesis, etc. RESULTS: Eighty-two systematic reviews were identified, except 6 reviews were excluded for repeatedly published or didn't comply with the enrolled criterion, 76 reviews concerning 51 kinds of diseases were enrolled for appraisal. Among them, 70 reviews evaluated the efficacy of TCM, mainly on Chinese herbs and 9 on acupuncture and moxibustion. In majority of the reviews, randomised controlled trials were included and the data resources were described, but in 26 reviews only the Chinese databases were searched and the description about data extraction and analysis method were too simple; and 70% of reviews assessed the quality of the included studies; none used flow chart to express the process of selection, inclusion and exclusion of studies. CONCLUSIONS: Few reviews or Meta-analysis reports reached the international standard and there is insufficient description of methodology for conducting systematic reviews, so it is hardly to be repeated. The authors suggested that advanced methodological training is necessary for reviewers.

Traditional chinese medicine for the treatment of chronic prostatitis in China: a systematic review and meta-analysis.: J Altern Complement Med. 2006 Oct;12(8):763-9 Authors: Chen JX, Hu LS

OBJECTIVE: To systematically evaluate the effectiveness of Chinese herbal medicine for treating chronic prostatitis (CPT) in China. DESIGN: Electronic medical database from China National Knowledge Infrastructure (CNKI) was searched, language is Chinese; date is from January 1, 1994 to December 31, 2003. A total of 108 trials were found, and all studies with words like "randomization" or "quasi-randomization" in their abstracts were included, whether they used blinding or not. Nineteen theses that met the entry criteria were downloaded and fully printed. Four groups were divided: Chinese herbs orally treated group (based on syndrome differentiation), Chinese herbs externally treated group, Chinese herbs orally and externally treated group, and integrated Western with Chinese herbs treated group. RESULTS: All 19 articles that met the entry criteria were clinical trial studies with low quality (Jadad Score <3). The results showed that Traditional Chinese Medicine (TCM) may benefit the patients who had CPT. However, from the results of the funnel plots analysis of all four groups of clinical trials that met the inclusion criteria in this systematic review are distant asymmetrical and irregular plots, which indicate that a positive publication bias may exist. There was no obvious evidence indicating that the efficacy of the therapy in the treated groups using TCM was superior to that of the control group (Western medicine treatment group). CONCLUSIONS: All of the four groups in the clinical trials have not provided evidence of evidence-based medicine (EBM) A class (including 1a, 1b, 1c level), failed to prove that the TCM may have beneficial effects for patients with CPT, because of low quality in all the trials and a positive publication bias. Therefore, in light of some positive outcomes, a good design of multicentered, randomized, parallel-controlled and blinding trials is needed in order to make further studies, and deserve further examination for the treatment of CPT with TCM.

Valerian for sleep: a systematic review and meta-analysis.: Am J Med. 2006 Dec;119(12):1005-12 Authors: Bent S, Padula A, Moore D, Patterson M, Mehling W

Insomnia affects approximately one-third of the adult population and contributes to increased rates of absenteeism, health care use, and social disability. Extracts of the roots of valerian (Valeriana officinalis) are widely used for inducing sleep and improving sleep quality. A systematic review of randomized, placebo-controlled trials of valerian for improving sleep quality is presented. An extensive literature search identified 16 eligible studies examining a total of 1093 patients. Most studies had significant methodologic problems, and the valerian doses, preparations, and length of treatment varied considerably. A dichotomous outcome of sleep quality (improved or not) was reported by 6 studies and showed a statistically significant benefit (relative risk of improved sleep = 1.8, 95% confidence interval, 1.2-2.9), but there was evidence of publication bias in this summary measure. The available evidence suggests that valerian might improve sleep quality without producing side effects. Future studies should assess a range of doses of standardized preparations of valerian and include standard measures of sleep quality and safety.

Astragalus-based Chinese herbs and platinum-based chemotherapy for advanced non-small-cell lung cancer: meta-analysis of randomized trials.: J Clin Oncol. 2006 Jan 20;24(3):419-30 Authors: McCulloch M, See C, Shu XJ, Broffman M, Kramer A, Fan WY, Gao J, Lieb W, Shieh K, Colford JM

PURPOSE: Systemic treatments for advanced non-small-cell lung cancer have low efficacy and high toxicity. Some Chinese herbal medicines have been reported to increase chemotherapy efficacy and reduce toxicity. In particular, Astragalus has been shown to have immunologic benefits by stimulating macrophage and natural killer cell activity and inhibiting T-helper cell type 2 cytokines. Many published studies have assessed the use of Astragalus and other Chinese herbal medicines in combination with chemotherapy. We sought to evaluate evidence from randomized trials that Astragalus-based Chinese herbal medicine combined with platinum-based chemotherapy (versus platinum-based chemotherapy alone) improves survival, increases tumor response, improves performance status, or reduces chemotherapy toxicity. METHODS: We searched CBM, MEDLINE, TCMLARS, EMBASE, Cochrane Library, and CCRCT databases for studies in any language. We grouped studies using the same herbal combinations for random-effects meta-analysis. RESULTS: Of 1,305 potentially relevant publications, 34 randomized studies representing 2,815 patients met inclusion criteria. Twelve studies (n = 940 patients) reported reduced risk of death at 12 months (risk ratio [RR] = 0.67; 95% CI, 0.52 to 0.87). Thirty studies (n = 2,472) reported improved tumor response data (RR = 1.34; 95% CI, 1.24 to 1.46). In subgroup analyses, Jin Fu Kang in two studies (n = 221 patients) reduced risk of death at 24 months (RR = 0.58; 95% CI, 0.49 to 0.68) and in three studies (n = 411) increased tumor response (RR = 1.76; 95% CI, 1.23 to 2.53). Ai Di injection (four studies; n = 257) stabilized or improved Karnofsky performance status (RR = 1.28; 95% CI, 1.12 to 1.46). CONCLUSION: Astragalus-based Chinese herbal medicine may increase effectiveness of platinum-based chemotherapy when combined with chemotherapy. These results require confirmation with rigorously controlled trials.

Compound salvia pellet, a traditional Chinese medicine, for the treatment of chronic stable angina pectoris compared with nitrates: a meta-analysis.: Med Sci Monit. 2005 Dec 19; 12(1): SR1-7
Wang G, Wang L, Xiong ZY, Mao B, Li TQ

Background: Compound salvia pellet (CSP), consisting of active herbal ingredients extracted from Danshen (salvia miltiorrhiza), Sanqi (panax notoginseng), and Borneol (Cinnamomum camphora), is taken most frequently by patients with angina pectoris in China. To determine the efficacy and safety of CSP for the treatment of stable angina pectoris (SAP), a meta-analysis was undertaken. Material/Methods: An extensive search including MEDLINE, EMBASE, BA, Chinese Biomedical Database (CBM), and Chinese Cochrane Centre Controlled Trials Register from 1994 to 2004 was performed. Data were extracted independently from the included trials by two reviewers. Statistical software (RevMan 4.1) provided by the Cochrane Collaboration was applied. Results: Twenty-seven randomized controlled trials (RCTs) (n=3722), regardless of language or publication status, were identified. Generally, the methodological quality of the trials, assessed by the Jadad scale, was low, except for one with 3 points. Statistical pooling of the results showed that, compared with nitrates, CSP treatment had significant effect on the improvement of angina symptoms (RR=1.13, 95%CI=[1.07, 1.20]), showed greater increased effect on the improvement of electrocardiogram (ECG) results (RR=1.39, 95%CI=[1.28, 1.50]), and the percentage of patients with adverse events was significantly decreased in the treatment of CSP in comparison with nitrates (2.4% vs. 29.7%). Conclusions: CSP has significant effect on the improvement of angina symptoms and ECG results with few adverse events. However, the methodological quality of clinical trials with CSP for SAP needs to be improved, and the outcome measures should include mortality, quality of life, and other end-points.