1.
Contemporary clinical research of traditional Chinese medicines for chronic hepatitis B in China: an analytical review.
Zhang, L, Wang, G, Hou, W, Li, P, Dulin, A, Bonkovsky, HL
Hepatology (Baltimore, Md.). 2010;(2):690-8
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Abstract
UNLABELLED Chronic hepatitis B (CHB) is major global health problem. In China, where about 120,000,000 persons are chronically infected, CHB has been treated for centuries with traditional Chinese medicines (TCMs). This review summarizes and meta-analyzes the results of randomized controlled trials (RCTs) of TCM formulations reported in China in 1998-2008 for treatment of CHB. RCTs comparing either TCM formulations alone or in combination with interferon (IFN) or lamivudine (LAM) versus IFN or LAM were included. Chinese electronic databases were searched. The methodological quality of RCTs was assessed using the Jadad scale. TCMs had a greater beneficial effect (P = 0.0003) than IFN and a slightly better effect (P = 0.01) than LAM on the normalization of serum alanine aminotransferase. TCMs had a similar beneficial effect when compared with IFN or LAM for CHB on antiviral activity as evidenced by the loss of serum hepatitis B e antigen and hepatitis B virus (HBV) DNA. TCMs enhanced IFN and LAM antiviral activities and improvements of liver function. The quality of many studies was poor; reports often lacked information regarding methods of randomization or blinding and adverse events. CONCLUSION Some TCMs seem effective as alternative remedies for patients with CHB, suggesting that further study of TCMs in the treatment of CHB is warranted, both in preclinical models of HBV infection and in higher quality RCTs worldwide.
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Evaluating the quality of research into a single prognostic biomarker: a systematic review and meta-analysis of 83 studies of C-reactive protein in stable coronary artery disease.
Hemingway, H, Philipson, P, Chen, R, Fitzpatrick, NK, Damant, J, Shipley, M, Abrams, KR, Moreno, S, McAllister, KS, Palmer, S, et al
PLoS medicine. 2010;(6):e1000286
Abstract
BACKGROUND Systematic evaluations of the quality of research on a single prognostic biomarker are rare. We sought to evaluate the quality of prognostic research evidence for the association of C-reactive protein (CRP) with fatal and nonfatal events among patients with stable coronary disease. METHODS AND FINDINGS We searched MEDLINE (1966 to 2009) and EMBASE (1980 to 2009) and selected prospective studies of patients with stable coronary disease, reporting a relative risk for the association of CRP with death and nonfatal cardiovascular events. We included 83 studies, reporting 61,684 patients and 6,485 outcome events. No study reported a prespecified statistical analysis protocol; only two studies reported the time elapsed (in months or years) between initial presentation of symptomatic coronary disease and inclusion in the study. Studies reported a median of seven items (of 17) from the REMARK reporting guidelines, with no evidence of change over time. The pooled relative risk for the top versus bottom third of CRP distribution was 1.97 (95% confidence interval [CI] 1.78-2.17), with substantial heterogeneity (I(2) = 79.5). Only 13 studies adjusted for conventional risk factors (age, sex, smoking, obesity, diabetes, and low-density lipoprotein [LDL] cholesterol) and these had a relative risk of 1.65 (95% CI 1.39-1.96), I(2) = 33.7. Studies reported ten different ways of comparing CRP values, with weaker relative risks for those based on continuous measures. Adjusting for publication bias (for which there was strong evidence, Egger's p<0.001) using a validated method reduced the relative risk to 1.19 (95% CI 1.13-1.25). Only two studies reported a measure of discrimination (c-statistic). In 20 studies the detection rate for subsequent events could be calculated and was 31% for a 10% false positive rate, and the calculated pooled c-statistic was 0.61 (0.57-0.66). CONCLUSION Multiple types of reporting bias, and publication bias, make the magnitude of any independent association between CRP and prognosis among patients with stable coronary disease sufficiently uncertain that no clinical practice recommendations can be made. Publication of prespecified statistical analytic protocols and prospective registration of studies, among other measures, might help improve the quality of prognostic biomarker research.
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Does open access in ophthalmology affect how articles are subsequently cited in research?
Lansingh, VC, Carter, MJ
Ophthalmology. 2009;(8):1425-31
Abstract
OBJECTIVE To determine whether the concept of open access affects how articles are cited in the field of ophthalmology. DESIGN Type of meta-analysis. PARTICIPANTS Examination of 480 articles in ophthalmology in the experimental protocol and 415 articles in the control protocol. METHODS Four subject areas were chosen to search the ophthalmology literature in the PubMed database using the terms "cataract," "diabetic retinopathy," "glaucoma," and "refractive errors." Searching started in December of 2003 and worked back in time to the beginning of the year. The number of subsequent citations for equal numbers of both open access and closed access (by subscription) articles was quantified using the Scopus database and Google search engine. Number of authors, article type, country/region in which the article was published, language, and funding data were also collected for each article. A control protocol was also carried out to ascertain that the sampling method was not systematically biased by matching 6 ophthalmology journals (3 open access, 3 closed access) using their impact factors, and employing the same search methodology to sample open access and closed access articles. MAIN OUTCOME MEASURES Number of citations. RESULTS The total number of citations was significantly higher for open access articles compared to closed access articles for Scopus (mean 15.2 versus 11.5, P < .0005, Mann-Whitney U = 20029, and Google (mean 6.4 versus 4.0, P < .0005, Mann-Whitney U = 21281). However, univariate general linear model (GLM) analysis showed that access was not a significant factor that explained the citation data. Author number, country/region of publication, subject area, language, and funding were the variables that had the most effect and were statistically significant. Control protocol results showed no significant difference between open and closed access articles in regard to number of citations found by Scopus: open access: mean = 17.8; SD (standard deviation) = 23.70; closed access: mean = 19.1; SD = 20.31; Mann-Whitney test, P = 0.730, Mann-Whitney U = 20584. CONCLUSIONS Unlike other fields of science, open access thus far has not affected how ophthalmology articles are cited in the literature.