Critical appraisal of clinical studies in Chinese herbal medicine.

The use of complementary and alternative medicine (CAM) is currently widespread and appears to be growing. As an increasing proportion of the population turns to CAM therapies, whether singly or in combination with allopathic medicine, the need for quality research in this area is reinforced. Much of this research consists of clinical studies aimed primarily at clinicians, yet challenges arising from poor methodological quality will occur when interpreting study findings and their implications. For clinicians to be effective consumers of the scientific literature, familiarization with the principles of evidence-based medicine (EBM) is essential. The goal of this review is to introduce clinicians to the concept of critical appraisal of clinical studies and foster critical thinking when reading research articles in order to best evaluate and incorporate study findings into their daily practice. Topics discussed in this article include: (1) fundamentals of EBM; (2) types of clinical studies; (3) hierarchy of evidence; (4) Consolidated Standard of Randomized Trials (CONSORT) statement to evaluate the quality of reporting in randomized controlled trials (RCTs); (5) methodologic quality rating scales for RCTs; and (6) issues specific to evaluating studies of Chinese herbal medicine.

[1]  J D Emerson,et al.  An empirical study of the possible relation of treatment differences to quality scores in controlled randomized clinical trials. , 1990, Controlled clinical trials.

[2]  A. Hrõbjartsson,et al.  Comparison of descriptions of allocation concealment in trial protocols and the published reports: cohort study , 2005, BMJ : British Medical Journal.

[3]  P. A. van den Brandt,et al.  The art of quality assessment of RCTs included in systematic reviews. , 2001, Journal of clinical epidemiology.

[4]  M. Egger,et al.  The hazards of scoring the quality of clinical trials for meta-analysis. , 1999, JAMA.

[5]  F. Cluzeau,et al.  Development and validation of an international appraisal instrument for assessing the quality of clinical practice guidelines: the AGREE project , 2003 .

[6]  N. Freemantle,et al.  CONSORT: An Important Step toward Evidence-Based Health Care , 1997, Annals of Internal Medicine.

[7]  D. Cook,et al.  Does quality of reports of randomised trials affect estimates of intervention efficacy reported in meta-analyses? , 1998, The Lancet.

[8]  R. J. Hayes,et al.  Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. , 1995, JAMA.

[9]  D. Cook,et al.  Systematic Reviews: Synthesis of Best Evidence for Clinical Decisions , 1997, Annals of Internal Medicine.

[10]  D. Moher,et al.  Improving the quality of randomized controlled trials in Chinese herbal medicine, part III: quality control of Chinese herbal medicine used in randomized controlled trials. , 2006, Zhong xi yi jie he xue bao = Journal of Chinese integrative medicine.

[11]  D. Sackett,et al.  Evidence based medicine: what it is and what it isn't , 1996, BMJ.

[12]  A R Jadad,et al.  Assessing the quality of reports of randomized clinical trials: is blinding necessary? , 1996, Controlled clinical trials.

[13]  Ming-yueh Tsay,et al.  Bibliometric analysis of the literature of randomized controlled trials. , 2005, Journal of the Medical Library Association : JMLA.

[14]  D. Moher,et al.  The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials. , 2001, Journal of the American Podiatric Medical Association.

[15]  C. Mulrow.  The medical review article: state of the science. , 1987, Annals of internal medicine.

[16]  The quest for unbiased research: Randomized clinical trials and the CONSORT reporting guidelines , 1997, Annals of neurology.

[17]  J. Sterne,et al.  How important are comprehensive literature searches and the assessment of trial quality in systematic reviews? Empirical study. , 2003, Health technology assessment.

[18]  David Evans,et al.  Hierarchy of evidence: a framework for ranking evidence evaluating healthcare interventions. , 2003, Journal of clinical nursing.

[19]  David Moher,et al.  Reporting Randomized, Controlled Trials of Herbal Interventions: An Elaborated CONSORT Statement , 2006, Annals of Internal Medicine.

[20]  F. Davidoff.  News from the International Committee of Medical Journal Editors , 2000, Annals of Internal Medicine.

[21]  A R Jadad,et al.  Assessing the quality of randomized controlled trials: an annotated bibliography of scales and checklists. , 1995, Controlled clinical trials.

[22]  C. Mulrow,et al.  Systematic Reviews: Rationale for systematic reviews , 1994, BMJ.

[23]  A R Jadad,et al.  Assessing the Quality of Randomized Controlled Trials: Current Issues and Future Directions , 1996, International Journal of Technology Assessment in Health Care.

[24]  D. Moher,et al.  Improving the quality of randomized controlled trials in Chinese herbal medicine, part II: control group design. , 2006, Zhong xi yi jie he xue bao = Journal of Chinese integrative medicine.

[25]  J. Ioannidis,et al.  Better Reporting of Harms in Randomized Trials: An Extension of the CONSORT Statement , 2004, Annals of Internal Medicine.

[26]  L. Gluud.  Bias in clinical intervention research. , 2006, American journal of epidemiology.

[27]  Roger B. Davis,et al.  Trends in use of complementary and alternative medicine by US adults: 1997-2002. , 2005, Alternative therapies in health and medicine.

[28]  E. Walters,et al.  Long-Term Trends in the Use of Complementary and Alternative Medical Therapies in the United States , 2001, Annals of Internal Medicine.

[29]  J. Hoey,et al.  CMAJ endorses the CONSORT statement. CONsolidation of Standards for Reporting Trials. , 1996, CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne.

[30]  I. Olkin,et al.  Improving the quality of reporting of randomized controlled trials. The CONSORT statement. , 1996, JAMA.

[31]  D. Moher,et al.  Improving the quality of randomized controlled trials in Chinese herbal medicine, part I: clinical trial design and methodology. , 2006, Zhong xi yi jie he xue bao = Journal of Chinese integrative medicine.