Brock R C, Goudie R J B, Peters C, Thaxter R, Gouliouris T, Illingworth C J R, Conway Morris A, Beggs C B, Butler M, Keevil V L
MRC Biostatistics Unit, School of Clinical Medicine, University of Cambridge, Cambridge, UK.
Department of Microbiology, NHS Greater Glasgow and Clyde, Glasgow, UK.
J Hosp Infect. 2025 Jan;155:1-8. doi: 10.1016/j.jhin.2024.09.017. Epub 2024 Oct 5.
Nosocomial infections are costly, and airborne transmission is increasingly recognized as important for spread. Air cleaning units (ACUs) may reduce transmission, but little research has focused on their effectiveness on open wards.
To assess whether ACUs reduce nosocomial severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), or other, infections on older adult inpatient wards.
This was a quasi-experimental before-and-after study on two intervention-control ward pairs in a UK teaching hospital. Infections were identified using routinely collected electronic health record data during 1 year of ACU implementation and the preceding year ('core study period'). Extended analyses included 6 months of additional data from one ward pair following ACU removal. Hazard ratios (HRs) were estimated through Cox regression controlling for age, sex, ward and background infection risk. The time that the ACUs were switched on was also recorded for Intervention Ward 2.
ACUs were initially feasible, but compliance reduced towards the end of the study (average operation in first vs second half of ACU time on Intervention Ward 2: 77% vs 53%). In total, 8171 admissions for >48 h (6112 patients, median age 85 years) were included. Overall, the incidence of ward-acquired SARS-CoV-2 was 3.8%. ACU implementation was associated with a non-significant trend of lower hazard for SARS-CoV-2 infection [HR core study period 0.90, 95% confidence interval (CI) 0.53-1.52; HR extended study period 0.78, 95% CI 0.53-1.14]. Only 1.5% of admissions resulted in other notable ward-acquired infections.
ACUs may reduce SARS-CoV-2 infection to a clinically meaningfully degree. Larger studies could reduce uncertainty, perhaps using a crossover design, and factors influencing acceptability to staff and patients should be explored further.
医院感染成本高昂，空气传播日益被认为是传播的重要途径。空气净化装置（ACU）可能会减少传播，但很少有研究关注其在开放式病房中的有效性。
评估空气净化装置是否能减少老年住院病房中医院获得性严重急性呼吸综合征冠状病毒2（SARS-CoV-2）或其他感染。
这是一项在英国一家教学医院对两个干预-对照病房对进行的前后对照准实验研究。在空气净化装置实施的1年期间及前一年（“核心研究期”），使用常规收集的电子健康记录数据识别感染情况。扩展分析包括在移除空气净化装置后，一个病房对额外6个月的数据。通过Cox回归估计风险比（HRs），并对年龄、性别、病房和背景感染风险进行控制。还记录了干预病房2中空气净化装置开启的时间。
空气净化装置最初是可行的，但在研究接近尾声时依从性降低（干预病房2中空气净化装置使用时间的前半段与后半段的平均运行率：77%对53%）。总共纳入了8171例住院时间超过48小时的患者（6112名患者，中位年龄85岁）。总体而言，病房获得性SARS-CoV-2的发生率为3.8%。空气净化装置的实施与SARS-CoV-2感染风险降低的非显著趋势相关[核心研究期风险比0.90，95%置信区间（CI）0.53 - 1.52；扩展研究期风险比0.78，95%CI 0.53 - 1.14]。只有1.5%的住院患者发生了其他值得注意的病房获得性感染。
空气净化装置可能会将SARS-CoV-2感染降低到具有临床意义的程度。更大规模的研究可能会减少不确定性，或许可以采用交叉设计，并且应进一步探索影响工作人员和患者接受度的因素。
