GRADE guidelines 6. Rating the quality of evidence - Imprecision

Gordon H. Guyatt, Andrew D. Oxman, Regina Kunz, Jan Brozek, Pablo Alonso-Coello, David Rind, P. J. Devereaux, Victor Manuel Montori, Bo Freyschuss, Gunn Vist, Roman Jaeschke, John W. Williams, Mohammad H Murad, David Sinclair, Yngve Falck-Ytter, Joerg Meerpohl, Craig Whittington, Kristian Thorlund, Jeff Andrews, Holger J. Schünemann

Research output: Contribution to journalArticle

929 Citations (Scopus)

Abstract

GRADE suggests that examination of 95% confidence intervals (CIs) provides the optimal primary approach to decisions regarding imprecision. For practice guidelines, rating down the quality of evidence (i.e., confidence in estimates of effect) is required if clinical action would differ if the upper versus the lower boundary of the CI represented the truth. An exception to this rule occurs when an effect is large, and consideration of CIs alone suggests a robust effect, but the total sample size is not large and the number of events is small. Under these circumstances, one should consider rating down for imprecision. To inform this decision, one can calculate the number of patients required for an adequately powered individual trial (termed the "optimal information size" [OIS]). For continuous variables, we suggest a similar process, initially considering the upper and lower limits of the CI, and subsequently calculating an OIS. Systematic reviews require a somewhat different approach. If the 95% CI excludes a relative risk (RR) of 1.0, and the total number of events or patients exceeds the OIS criterion, precision is adequate. If the 95% CI includes appreciable benefit or harm (we suggest an RR of under 0.75 or over 1.25 as a rough guide) rating down for imprecision may be appropriate even if OIS criteria are met.

Original languageEnglish (US)
Pages (from-to)1283-1293
Number of pages11
JournalJournal of Clinical Epidemiology
Volume64
Issue number12
DOIs
StatePublished - Dec 2011

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Guidelines
Confidence Intervals
Practice Guidelines
Sample Size

Keywords

  • Confidence in estimates
  • Confidence intervals
  • GRADE
  • Imprecision
  • Optimal information size
  • Quality of evidence

ASJC Scopus subject areas

  • Epidemiology

Cite this

Guyatt, G. H., Oxman, A. D., Kunz, R., Brozek, J., Alonso-Coello, P., Rind, D., ... Schünemann, H. J. (2011). GRADE guidelines 6. Rating the quality of evidence - Imprecision. Journal of Clinical Epidemiology, 64(12), 1283-1293. https://doi.org/10.1016/j.jclinepi.2011.01.012

GRADE guidelines 6. Rating the quality of evidence - Imprecision. / Guyatt, Gordon H.; Oxman, Andrew D.; Kunz, Regina; Brozek, Jan; Alonso-Coello, Pablo; Rind, David; Devereaux, P. J.; Montori, Victor Manuel; Freyschuss, Bo; Vist, Gunn; Jaeschke, Roman; Williams, John W.; Murad, Mohammad H; Sinclair, David; Falck-Ytter, Yngve; Meerpohl, Joerg; Whittington, Craig; Thorlund, Kristian; Andrews, Jeff; Schünemann, Holger J.

In: Journal of Clinical Epidemiology, Vol. 64, No. 12, 12.2011, p. 1283-1293.

Research output: Contribution to journalArticle

Guyatt, GH, Oxman, AD, Kunz, R, Brozek, J, Alonso-Coello, P, Rind, D, Devereaux, PJ, Montori, VM, Freyschuss, B, Vist, G, Jaeschke, R, Williams, JW, Murad, MH, Sinclair, D, Falck-Ytter, Y, Meerpohl, J, Whittington, C, Thorlund, K, Andrews, J & Schünemann, HJ 2011, 'GRADE guidelines 6. Rating the quality of evidence - Imprecision', Journal of Clinical Epidemiology, vol. 64, no. 12, pp. 1283-1293. https://doi.org/10.1016/j.jclinepi.2011.01.012
Guyatt GH, Oxman AD, Kunz R, Brozek J, Alonso-Coello P, Rind D et al. GRADE guidelines 6. Rating the quality of evidence - Imprecision. Journal of Clinical Epidemiology. 2011 Dec;64(12):1283-1293. https://doi.org/10.1016/j.jclinepi.2011.01.012
Guyatt, Gordon H. ; Oxman, Andrew D. ; Kunz, Regina ; Brozek, Jan ; Alonso-Coello, Pablo ; Rind, David ; Devereaux, P. J. ; Montori, Victor Manuel ; Freyschuss, Bo ; Vist, Gunn ; Jaeschke, Roman ; Williams, John W. ; Murad, Mohammad H ; Sinclair, David ; Falck-Ytter, Yngve ; Meerpohl, Joerg ; Whittington, Craig ; Thorlund, Kristian ; Andrews, Jeff ; Schünemann, Holger J. / GRADE guidelines 6. Rating the quality of evidence - Imprecision. In: Journal of Clinical Epidemiology. 2011 ; Vol. 64, No. 12. pp. 1283-1293.
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