Targeting Infection Prevention: JAMA Commentary on Methods for Comparative Effectiveness Research
Healthcare-acquired infections, particularly those due to antimicrobial-resistant bacteria, have received significant attention in recent years, and success in curbing their emergence remains elusive. Few new classes of antibiotics are even in the earliest stages of development; moreover, the evidence base on which potential infection-prevention strategies must be built is severely limited, as very few of the necessary clinical trials have been conducted. To effectively protect patients, rigorous studies must be conducted to assess the comparative effectiveness of different infection-prevention interventions. This Commentary focuses on three complementary methods for comparative effectiveness research in infection prevention: cluster randomized trials, quasi-experimental studies, and mathematical models.
The cluster-randomized clinical trial is well-suited to study the comparative effectiveness of population-level interventions. Cluster-randomized trials may involve randomization at different levels, including the full hospital or individual hospital units. These trials are complicated, costly, and time-consuming, but vital if population-level interventions are to be adequately evaluated. An alternative is the quasi-experimental (QE) study, wherein interventions are evaluated without the use of a randomized control group, and changes in the outcomes are compared before and after the time of the intervention. QE designs have significant advantages, e.g., efficiency, generalizability, and the ability to assess the temporal relationship between non-randomizable events (e.g., legislative mandates) and outcomes. Mathematical simulation models assume statistical association (e.g., improving hand-hygiene compliance is associated with reduced transmission of infectious agents) and predict the consequences of the assumption in many potential hospital settings. These studies allow for interpreting existing epidemiological studies and testing hypotheses, such as the conditions under which an intervention might be most cost-effective.
The authors suggest that the focused and coordinated use of well-designed quasi-experiments, cluster-randomized trials, and mathematical models offer significant potential opportunities for targeting infection prevention efforts.
Perencevich E and Lautenbach E. Infection prevention and comparative effectiveness research. Commentary JAMA April 13, 2011;305(14):1482-3.
Dr. Perencevich is funded by HSR&D (IIR 09-099) and is part of HSR&D’s Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City, IA.