Magnusson Amanda, Ahle Margareta, Swolin-Eide Diana, Elfvin Anders, Andersson Roland E
Department of Pediatrics, Institution of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Division of Radiology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
Acta Paediatr. 2017 Jul;106(7):1097-1102. doi: 10.1111/apa.13851. Epub 2017 Apr 24.
This study investigated space-time clustering of neonatal necrotising enterocolitis over three decades.
Space-time clustering analyses objects that are grouped by a specific place and time. The Knox test and Kulldorff's scan statistic were used to analyse space-time clusters in 808 children diagnosed with necrotising enterocolitis in a national cohort of 2 389 681 children born between 1987 and 2009 in Sweden. The municipality the mother lived in and the delivery hospital defined closeness in space and the time between when the cases were born - seven, 14 and 21 days - defined closeness in time.
The Knox test showed no indication of space-time clustering at the residential level, but clear indications at the hospital level in all the time windows: seven days (p = 0.026), 14 days (p = 0.010) and 21 days (p = 0.004). Significant clustering at the hospital level was found during 1987-1997, but not during 1998-2009. Kulldorff's scan statistic found seven significant clusters at the hospital level.
Space-time clustering was found at the hospital but not residential level, suggesting a contagious environmental effect after delivery, but not in the prenatal period. The decrease in clustering over time may reflect improved routines to minimise the risk of contagion between patients receiving neonatal care.
本研究调查了三十年间新生儿坏死性小肠结肠炎的时空聚集情况。
时空聚集分析按特定地点和时间分组的对象。采用诺克斯检验和库尔多夫扫描统计量，对瑞典1987年至2009年出生的全国队列2389681名儿童中确诊为坏死性小肠结肠炎的808名儿童进行时空聚集分析。母亲居住的市政区域和分娩医院定义空间上的接近程度，病例出生之间的时间间隔（7天、14天和21天）定义时间上的接近程度。
诺克斯检验显示在居住层面没有时空聚集的迹象，但在医院层面的所有时间窗口都有明显迹象：7天（p = 0.026）、14天（p = 0.010）和21天（p = 0.004）。在1987 - 1997年期间发现医院层面有显著聚集，但在1998 - 2009年期间没有。库尔多夫扫描统计量在医院层面发现了7个显著聚集区。
在医院层面发现了时空聚集，但在居住层面未发现，这表明分娩后存在传染性环境影响，但在产前阶段不存在。随着时间推移聚集现象的减少可能反映出为将接受新生儿护理的患者之间的传染风险降至最低而改进的常规措施。
