Prosser Aaron, Helfer Bartosz, Streiner David L
Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.
Meta Research Centre, University of Wrocław, Wrocław, Poland.
Popul Health Metr. 2024 Dec 23;22(1):39. doi: 10.1186/s12963-024-00360-y.
We have previously developed and reported on a procedure for estimating the purported benefits of immunity mandates using a novel variant of the number needed to treat (NNT) which we called the number needed to isolate (NNI). Here we demonstrate its broader properties as a useful population health metric.
The NNI is analogous to the number needed to treat (NNT = 1/ARR), except the absolute risk reduction (ARR) is the absolute transmission risk in a specific population. The NNI is the number of susceptible hosts in a population who need to be isolated to prevent one transmission event from them. The properties and utility of the NNI were modeled using simulated data and its model predictions were validated using real world data. The properties of the NNI are described for three categories of data from a previous study on transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): (1) in different settings, (2) after a specific exposure and (3) depending on symptomaticity status of susceptible hosts.
We provide a demonstration of the utility of the NNI as a valuable population health metric to quantify the transmission reductions from isolation interventions.
我们之前开发并报告了一种程序，该程序使用一种新型的治疗所需人数（NNT）变体来估计免疫授权的所谓益处，我们将其称为隔离所需人数（NNI）。在此，我们展示了它作为一种有用的人群健康指标的更广泛特性。
NNI类似于治疗所需人数（NNT = 1/ARR），不同之处在于绝对风险降低率（ARR）是特定人群中的绝对传播风险。NNI是人群中需要被隔离以防止其中一人引发一次传播事件的易感宿主数量。使用模拟数据对NNI的特性和效用进行了建模，并使用实际数据对其模型预测进行了验证。针对先前一项关于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）传播性的研究中的三类数据描述了NNI的特性：（1）在不同环境中，（2）在特定暴露之后，以及（3）取决于易感宿主的症状状态。
我们证明了NNI作为一种有价值的人群健康指标的效用，可用于量化隔离干预措施带来的传播减少情况。
