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. 2001 Aug;55(8):569–572. doi: 10.1136/jech.55.8.569

Participation of epidemiologists and/or biostatisticians and methodological quality of published controlled clinical trials

M Delgado-Rodriguez 1, M Ruiz-Canela 1, J De Irala-Estevez 1, J Llorca 1, M Martinez-Gonzalez 1
PMCID: PMC1731954  PMID: 11449014

Abstract

STUDY OBJECTIVE—This study assessed several methodological aspects related to the quality of published controlled clinical trials (CCTs) in relation to the participation of an epidemiologist/biostatistician (E/B).
DESIGN—Handsearch of CCTs published in four medical leading journals for 1993-1995.
METHODS—Quality variables, abstracted from a review, were related to authors' specialties. Five hundred and ninety four CCTs were identified via a hand search. The department/unit membership was used to attribute authors' specialties. Of 594 CCTs identified, in 127 the authors' specialties could not be known, leaving 467 trials for analysis.
RESULTS—E/B participation occurred in 178 trials (38.1%). This participation was more frequent in multicentric, bigger, and in those trials describing any funding agency. These factors were controlled for in the analysis. E/B participation was positively associated with pre-study sample size estimation (OR = 1.5, 95% confidence intervals (CI) 1.0, 2.3), with reporting the dates for starting/ending the study (OR = 2.1, 95% CI 1.4, 3.3), with using an objectively assessed outcome (OR = 2.4, 95% CI 1.2, 4.6) and with the intention to treat principle (OR = 2.0, 95% CI 1.3, 3.0). The overall quality score was higher in trials where E/B participated.
CONCLUSIONS—The results suggest that E/B improve the quality (at least of reports) of clinical trials. Given that quality of research is frequently used to evaluate potential sources of heterogeneity between trials, these results are relevant for meta-analysis.


Keywords: clinical trials; authorship; meta-analysis

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Selected References

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  1. Begg C., Cho M., Eastwood S., Horton R., Moher D., Olkin I., Pitkin R., Rennie D., Schulz K. F., Simel D. Improving the quality of reporting of randomized controlled trials. The CONSORT statement. JAMA. 1996 Aug 28;276(8):637–639. doi: 10.1001/jama.276.8.637. [DOI] [PubMed] [Google Scholar]
  2. Berlin J. A., Colditz G. A. A meta-analysis of physical activity in the prevention of coronary heart disease. Am J Epidemiol. 1990 Oct;132(4):612–628. doi: 10.1093/oxfordjournals.aje.a115704. [DOI] [PubMed] [Google Scholar]
  3. Detsky A. S., Naylor C. D., O'Rourke K., McGeer A. J., L'Abbé K. A. Incorporating variations in the quality of individual randomized trials into meta-analysis. J Clin Epidemiol. 1992 Mar;45(3):255–265. doi: 10.1016/0895-4356(92)90085-2. [DOI] [PubMed] [Google Scholar]
  4. Greenland S. Invited commentary: a critical look at some popular meta-analytic methods. Am J Epidemiol. 1994 Aug 1;140(3):290–296. doi: 10.1093/oxfordjournals.aje.a117248. [DOI] [PubMed] [Google Scholar]
  5. 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]
  6. 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]
  7. Olkin I. Re: "A critical look at some popular meta-analytic methods". Am J Epidemiol. 1994 Aug 1;140(3):297–301. doi: 10.1093/oxfordjournals.aje.a117249. [DOI] [PubMed] [Google Scholar]
  8. Ruiz-Canela M., Martínez-González M. A., Gómez-Gracia E., Fernández-Crehuet J. Informed consent and approval by institutional review boards in published reports on clinical trials. N Engl J Med. 1999 Apr 8;340(14):1114–1115. doi: 10.1056/NEJM199904083401412. [DOI] [PubMed] [Google Scholar]
  9. 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]

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