Skip to main content
NCBI home page
Indian Journal of Psychiatry logoLink to Indian Journal of Psychiatry
. 1998 Apr-Jun;40(2):135–148.

THE RELEVANCE TO META-ANALYSIS, SYSTEMATIC REVIEWS AND THE COCHRANE COLLABORATION TO CLINICAL PSYCHIATRY

Prathap Tharyan 1,✉
PMCID: PMC2965837  PMID: 21494461

Abstract

Traditional review articles provide clinicians with syntheses of the medical literature but are criticised as being haphazard in their methodology and biased in their conclusions. Systematic reviews use rigorous methods to minimise bias and statistical methods to synthesise results (meta-analysis) that increase power and precision. They permit investigation of generalisability and consistency, improve transparency of methodology, and enhance reproducibility. This article examines the science of systematic reviews and meta-analysis and their relevance to clinical psychiatry. It evaluates the potential errors and sources of bias of meta-analysis, and offers guidelines for evaluation of systematic reviews. It highlights the efforts of the Cochrane Collaboration which is an international organisation involved in preparing, maintaining and disseminating highly structured, frequently updated, and good quality systematic reviews of the effects of interventions in all aspects of health care.

Keywords: Meta-analysis, systematic reviews, epidemiological methods, bias, research design

Full Text

The Full Text of this article is available as a PDF (592.1 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adams C. E., Power A., Frederick K., Lefebvre C. An investigation of the adequacy of MEDLINE searches for randomized controlled trials (RCTs) of the effects of mental health care. Psychol Med. 1994 Aug;24(3):741–748. doi: 10.1017/s0033291700027896. [DOI] [PubMed] [Google Scholar]
  2. Adams C., Gelder M. The case for establishing a register of randomised controlled trials of mental health care. A widely accessible register will minimise bias for those reviewing care. Br J Psychiatry. 1994 Apr;164(4):433–436. doi: 10.1192/bjp.164.4.433. [DOI] [PubMed] [Google Scholar]
  3. Altman D. G. Better reporting of randomised controlled trials: the CONSORT statement. BMJ. 1996 Sep 7;313(7057):570–571. doi: 10.1136/bmj.313.7057.570. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Antman E. M., Lau J., Kupelnick B., Mosteller F., Chalmers T. C. A comparison of results of meta-analyses of randomized control trials and recommendations of clinical experts. Treatments for myocardial infarction. JAMA. 1992 Jul 8;268(2):240–248. [PubMed] [Google Scholar]
  5. Bailar J. C., 3rd The practice of meta-analysis. J Clin Epidemiol. 1995 Jan;48(1):149–157. doi: 10.1016/0895-4356(94)00149-k. [DOI] [PubMed] [Google Scholar]
  6. Bailar J. C., 3rd The promise and problems of meta-analysis. N Engl J Med. 1997 Aug 21;337(8):559–561. doi: 10.1056/NEJM199708213370810. [DOI] [PubMed] [Google Scholar]
  7. Berlin J. A., Laird N. M., Sacks H. S., Chalmers T. C. A comparison of statistical methods for combining event rates from clinical trials. Stat Med. 1989 Feb;8(2):141–151. doi: 10.1002/sim.4780080202. [DOI] [PubMed] [Google Scholar]
  8. Brown S. Excess mortality of schizophrenia. A meta-analysis. Br J Psychiatry. 1997 Dec;171:502–508. doi: 10.1192/bjp.171.6.502. [DOI] [PubMed] [Google Scholar]
  9. Chalmers T. C., Celano P., Sacks H. S., Smith H., Jr Bias in treatment assignment in controlled clinical trials. N Engl J Med. 1983 Dec 1;309(22):1358–1361. doi: 10.1056/NEJM198312013092204. [DOI] [PubMed] [Google Scholar]
  10. Cook D. J., Sackett D. L., Spitzer W. O. Methodologic guidelines for systematic reviews of randomized control trials in health care from the Potsdam Consultation on Meta-Analysis. J Clin Epidemiol. 1995 Jan;48(1):167–171. doi: 10.1016/0895-4356(94)00172-m. [DOI] [PubMed] [Google Scholar]
  11. DerSimonian R., Laird N. Meta-analysis in clinical trials. Control Clin Trials. 1986 Sep;7(3):177–188. doi: 10.1016/0197-2456(86)90046-2. [DOI] [PubMed] [Google Scholar]
  12. Dickersin K., Chan S., Chalmers T. C., Sacks H. S., Smith H., Jr Publication bias and clinical trials. Control Clin Trials. 1987 Dec;8(4):343–353. doi: 10.1016/0197-2456(87)90155-3. [DOI] [PubMed] [Google Scholar]
  13. Dickersin K., Scherer R., Lefebvre C. Identifying relevant studies for systematic reviews. BMJ. 1994 Nov 12;309(6964):1286–1291. doi: 10.1136/bmj.309.6964.1286. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Dickersin K. The existence of publication bias and risk factors for its occurrence. JAMA. 1990 Mar 9;263(10):1385–1389. [PubMed] [Google Scholar]
  15. Easterbrook P. J., Berlin J. A., Gopalan R., Matthews D. R. Publication bias in clinical research. Lancet. 1991 Apr 13;337(8746):867–872. doi: 10.1016/0140-6736(91)90201-y. [DOI] [PubMed] [Google Scholar]
  16. Egger M., Smith G. D. Misleading meta-analysis. BMJ. 1995 Mar 25;310(6982):752–754. doi: 10.1136/bmj.310.6982.752. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Feinstein A. R. Meta-analysis: statistical alchemy for the 21st century. J Clin Epidemiol. 1995 Jan;48(1):71–79. doi: 10.1016/0895-4356(94)00110-c. [DOI] [PubMed] [Google Scholar]
  18. Gardner M. J., Altman D. G. Confidence intervals rather than P values: estimation rather than hypothesis testing. Br Med J (Clin Res Ed) 1986 Mar 15;292(6522):746–750. doi: 10.1136/bmj.292.6522.746. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Geddes J. R., Harrison P. J. Closing the gap between research and practice. Br J Psychiatry. 1997 Sep;171:220–225. doi: 10.1192/bjp.171.3.220. [DOI] [PubMed] [Google Scholar]
  20. Goodman S. N. Have you ever meta-analysis you didn't like? Ann Intern Med. 1991 Feb 1;114(3):244–246. doi: 10.7326/0003-4819-114-3-244. [DOI] [PubMed] [Google Scholar]
  21. Gøtzsche P. C. Reference bias in reports of drug trials. Br Med J (Clin Res Ed) 1987 Sep 12;295(6599):654–656. [PMC free article] [PubMed] [Google Scholar]
  22. Harris E. C., Barraclough B. Suicide as an outcome for mental disorders. A meta-analysis. Br J Psychiatry. 1997 Mar;170:205–228. doi: 10.1192/bjp.170.3.205. [DOI] [PubMed] [Google Scholar]
  23. Haynes R. B. Clinical review articles. BMJ. 1992 Feb 8;304(6823):330–331. doi: 10.1136/bmj.304.6823.330. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Huston P., Moher D. Redundancy, disaggregation, and the integrity of medical research. Lancet. 1996 Apr 13;347(9007):1024–1026. doi: 10.1016/s0140-6736(96)90153-1. [DOI] [PubMed] [Google Scholar]
  25. Khan K. S., Daya S., Jadad A. The importance of quality of primary studies in producing unbiased systematic reviews. Arch Intern Med. 1996 Mar 25;156(6):661–666. [PubMed] [Google Scholar]
  26. Lau J., Antman E. M., Jimenez-Silva J., Kupelnick B., Mosteller F., Chalmers T. C. Cumulative meta-analysis of therapeutic trials for myocardial infarction. N Engl J Med. 1992 Jul 23;327(4):248–254. doi: 10.1056/NEJM199207233270406. [DOI] [PubMed] [Google Scholar]
  27. Lau J., Schmid C. H., Chalmers T. C. Cumulative meta-analysis of clinical trials builds evidence for exemplary medical care. J Clin Epidemiol. 1995 Jan;48(1):45–60. doi: 10.1016/0895-4356(94)00106-z. [DOI] [PubMed] [Google Scholar]
  28. Laupacis A., Sackett D. L., Roberts R. S. An assessment of clinically useful measures of the consequences of treatment. N Engl J Med. 1988 Jun 30;318(26):1728–1733. doi: 10.1056/NEJM198806303182605. [DOI] [PubMed] [Google Scholar]
  29. LeLorier J., Grégoire G., Benhaddad A., Lapierre J., Derderian F. Discrepancies between meta-analyses and subsequent large randomized, controlled trials. N Engl J Med. 1997 Aug 21;337(8):536–542. doi: 10.1056/NEJM199708213370806. [DOI] [PubMed] [Google Scholar]
  30. Licht R. W., Gouliaev G., Vestergaard P., Frydenberg M. Generalisability of results from randomised drug trials. A trial on antimanic treatment. Br J Psychiatry. 1997 Mar;170:264–267. doi: 10.1192/bjp.170.3.264. [DOI] [PubMed] [Google Scholar]
  31. Moher D., Jadad A. R., Nichol G., Penman M., Tugwell P., Walsh S. Assessing the quality of randomized controlled trials: an annotated bibliography of scales and checklists. Control Clin Trials. 1995 Feb;16(1):62–73. doi: 10.1016/0197-2456(94)00031-w. [DOI] [PubMed] [Google Scholar]
  32. Mulrow C. D. Rationale for systematic reviews. BMJ. 1994 Sep 3;309(6954):597–599. doi: 10.1136/bmj.309.6954.597. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Mulrow C. D. The medical review article: state of the science. Ann Intern Med. 1987 Mar;106(3):485–488. doi: 10.7326/0003-4819-106-3-485. [DOI] [PubMed] [Google Scholar]
  34. Naylor C. D. Meta-analysis and the meta-epidemiology of clinical research. BMJ. 1997 Sep 13;315(7109):617–619. doi: 10.1136/bmj.315.7109.617. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Oxman A. D., Guyatt G. H. A consumer's guide to subgroup analyses. Ann Intern Med. 1992 Jan 1;116(1):78–84. doi: 10.7326/0003-4819-116-1-78. [DOI] [PubMed] [Google Scholar]
  36. Oxman A. D., Guyatt G. H. Guidelines for reading literature reviews. CMAJ. 1988 Apr 15;138(8):697–703. [PMC free article] [PubMed] [Google Scholar]
  37. Oxtoby A., Jones A., Robinson M. Is your 'double-blind' design truly double-blind? Br J Psychiatry. 1989 Nov;155:700–701. doi: 10.1192/s0007125000018225. [DOI] [PubMed] [Google Scholar]
  38. Rosenthal R., Kleid J. J., Cohen M. V. Abnormal mitral valve motion associated with ventricular septal defect following acute myocardial infarction. Am Heart J. 1979 Nov;98(5):638–641. doi: 10.1016/0002-8703(79)90291-6. [DOI] [PubMed] [Google Scholar]
  39. Sackett D. L. Bias in analytic research. J Chronic Dis. 1979;32(1-2):51–63. doi: 10.1016/0021-9681(79)90012-2. [DOI] [PubMed] [Google Scholar]
  40. Schulz K. F., Chalmers I., Hayes R. J., Altman D. G. Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA. 1995 Feb 1;273(5):408–412. doi: 10.1001/jama.273.5.408. [DOI] [PubMed] [Google Scholar]
  41. Shapiro S. Is meta-analysis a valid approach to the evaluation of small effects in observational studies? J Clin Epidemiol. 1997 Mar;50(3):223–229. doi: 10.1016/s0895-4356(96)00360-5. [DOI] [PubMed] [Google Scholar]
  42. Shapiro S. Meta-analysis/Shmeta-analysis. Am J Epidemiol. 1994 Nov 1;140(9):771–778. doi: 10.1093/oxfordjournals.aje.a117324. [DOI] [PubMed] [Google Scholar]
  43. Smith M. L., Glass G. V. Meta-analysis of psychotherapy outcome studies. Am Psychol. 1977 Sep;32(9):752–760. doi: 10.1037//0003-066x.32.9.752. [DOI] [PubMed] [Google Scholar]
  44. Stewart L. A., Parmar M. K. Meta-analysis of the literature or of individual patient data: is there a difference? Lancet. 1993 Feb 13;341(8842):418–422. doi: 10.1016/0140-6736(93)93004-k. [DOI] [PubMed] [Google Scholar]
  45. Teo K. K., Yusuf S., Collins R., Held P. H., Peto R. Effects of intravenous magnesium in suspected acute myocardial infarction: overview of randomised trials. BMJ. 1991 Dec 14;303(6816):1499–1503. doi: 10.1136/bmj.303.6816.1499. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Villar J., Carroli G., Belizán J. M. Predictive ability of meta-analyses of randomised controlled trials. Lancet. 1995 Mar 25;345(8952):772–776. doi: 10.1016/s0140-6736(95)90646-0. [DOI] [PubMed] [Google Scholar]
  47. Yusuf S., Peto R., Lewis J., Collins R., Sleight P. Beta blockade during and after myocardial infarction: an overview of the randomized trials. Prog Cardiovasc Dis. 1985 Mar-Apr;27(5):335–371. doi: 10.1016/s0033-0620(85)80003-7. [DOI] [PubMed] [Google Scholar]

Articles from Indian Journal of Psychiatry are provided here courtesy of Wolters Kluwer -- Medknow Publications

RESOURCES