Estimating the impact post randomization changes in staff behavior in infection prevention trials: a mathematical...

Area of Science:

• Infectious Disease Epidemiology
• Clinical Trial Methodology
• Healthcare-Associated Infections

Background:

• Randomized controlled trials (RCTs) for behavior-based interventions are susceptible to post-randomization changes between study arms.
• Assesses the impact of such changes in a large, multicenter study on universal contact precautions for preventing infection transmission in intensive care units (ICUs).

Purpose of the Study:

• To evaluate the influence of altered patient visitation rates on methicillin-resistant Staphylococcus aureus (MRSA) acquisition.
• To understand how behavior changes affect outcomes in infection control randomized controlled trials (RCTs).

Main Methods:

• Constructed a stochastic mathematical model of MRSA acquisition in a simulated 18-bed ICU.
• Utilized parameters from a contact precautions study reporting a post-randomization change in contact rates (fewer visits in the treatment arm).
• Explored the impact of various interpretations of this visitation change on MRSA acquisition rates.

Main Results:

• Simulated scenarios where contact precautions led to reduced patient visitation showed a mean decrease in MRSA acquisition rate of 37%.
• This reduction in visitation accounted for a substantial portion of the observed effect in the original trial.
• Demonstrates the significant influence of contact rate modifications on infection control trial outcomes.

Conclusions:

• Behavioral changes affecting contact rates can drastically alter results in infection control RCTs.
• Recommends careful monitoring for such changes during studies.
• Suggests pre-study assessment of potential behavioral impacts is crucial for robust trial design.