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. 2019 Jun;40(6):686-692.
doi: 10.1017/ice.2019.48. Epub 2019 May 2.

Design, implementation, and analysis considerations for cluster-randomized trials in infection control and hospital epidemiology: A systematic review

Lyndsay M O'Hara  1 , Natalia Blanco  1 , Surbhi Leekha  1 , Kristen A Stafford  1 , Gerard P Slobogean  2 , Emilie Ludeman  3 , Anthony D Harris  1 ; CDC Prevention Epicenters Program
Affiliations

Design, implementation, and analysis considerations for cluster-randomized trials in infection control and hospital epidemiology: A systematic review

Lyndsay M O'Hara et al. Infect Control Hosp Epidemiol. 2019 Jun.

Abstract

Background: In cluster-randomized trials (CRT), groups rather than individuals are randomized to interventions. The aim of this study was to present critical design, implementation, and analysis issues to consider when planning a CRT in the healthcare setting and to synthesize characteristics of published CRT in the field of healthcare epidemiology.

Methods: A systematic review was conducted to identify CRT with infection control outcomes.

Results: We identified the following 7 epidemiological principles: (1) identify design type and justify the use of CRT; (2) account for clustering when estimating sample size and report intraclass correlation coefficient (ICC)/coefficient of variation (CV); (3) obtain consent; (4) define level of inference; (5) consider matching and/or stratification; (6) minimize bias and/or contamination; and (7) account for clustering in the analysis. Among 44 included studies, the most common design was CRT with crossover (n = 15, 34%), followed by parallel CRT (n = 11, 25%) and stratified CRT (n = 7, 16%). Moreover, 22 studies (50%) offered justification for their use of CRT, and 20 studies (45%) demonstrated that they accounted for clustering at the design phase. Only 15 studies (34%) reported the ICC, CV, or design effect. Also, 15 studies (34%) obtained waivers of consent, and 7 (16%) sought consent at the cluster level. Only 17 studies (39%) matched or stratified at randomization, and 10 studies (23%) did not report efforts to mitigate bias and/or contamination. Finally, 29 studies (88%) accounted for clustering in their analyses.

Conclusions: We must continue to improve the design and reporting of CRT to better evaluate the effectiveness of infection control interventions in the healthcare setting.

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Conflict of interest statement

Conflicts of interest. All authors report no conflicts of interest relevant to this article.

Figures

Fig. 1.
Fig. 1.
PRISMA flow diagram* of search results. *From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement.
See this image and copyright information in PMC

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