Lofgren Eric T
Paul G. Allen School for Global Animal Health, Washington State University, 240 SE Ott Road, Room 311, Pullman, WA, 99164-7090, USA.
Community Health Analytics Initiative, Washington State University, Pullman, WA, USA.
BMC Infect Dis. 2017 Aug 3;17(1):539. doi: 10.1186/s12879-017-2632-1.
Randomized controlled trials (RCTs) of behavior-based interventions are particularly vulnerable to post-randomization changes between study arms. We assess the impact of such a change in a large, multicenter study of universal contact precautions to prevent infection transmission in intensive care units.
We construct a stochastic mathematical model of methicillin-resistant Staphylococcus aureus (MRSA) acquisition in a simulated 18-bed intensive care unit (ICU). Using parameters from a recent study of contact precautions that reported a post-randomization change in contact rates, with fewer visits observed in the treatment arm, we explore the impact of several possible interpretations of this change on MRSA acquisition rates.
Scenarios where contact precautions resulted in less patient visitation resulted in a mean decrease in MRSA acquisition rate of 37%, accounting for much of the effect reported in the trial.
Behavior changes that impact the contact rate have the potential to drastically alter the results of RCTs in infection control settings. Careful monitoring for these changes, and an assessment of which changes will likely have the greatest impact on the study before the study begins are both recommended.
基于行为的干预措施的随机对照试验（RCTs）特别容易受到研究组之间随机化后变化的影响。我们在一项大型多中心研究中评估了这种变化的影响，该研究旨在采用通用接触预防措施预防重症监护病房（ICU）内的感染传播。
我们构建了一个模拟的18床重症监护病房（ICU）中耐甲氧西林金黄色葡萄球菌（MRSA）感染的随机数学模型。利用近期一项接触预防措施研究中的参数，该研究报告了随机化后接触率的变化，即治疗组的探视次数减少，我们探讨了对这一变化的几种可能解释对MRSA感染率的影响。
接触预防措施导致患者探视减少的情况使MRSA感染率平均降低了37%，这在很大程度上解释了试验中报告的效果。
影响接触率的行为变化有可能极大地改变感染控制环境中RCTs的结果。建议在研究开始前仔细监测这些变化，并评估哪些变化可能对研究产生最大影响。
