Peninsula Technology Assessment Group, University of Exeter Medical School, Exeter, UK.
Department of Public Health, Environments and Society, London School of Hygiene and Tropical Medicine, London, UK.
BMC Med Res Methodol. 2022 Feb 27;22(1):57. doi: 10.1186/s12874-022-01537-5.
The healthy context paradox, originally described with respect to school-level bullying interventions, refers to the generation of differences in mental wellbeing amongst those who continue to experience bullying even after interventions successfully reduce victimisation. Using data from the INCLUSIVE trial of restorative practice in schools, we relate this paradox to the need to theorise potential harms when developing interventions; formulate the healthy context paradox in a more general form defined by mediational relationships and cluster-level interventions; and propose two statistical models for testing the healthy context paradox informed by multilevel mediation methods, with relevance to structural and individual explanations for this paradox.
We estimated two multilevel mediation models with bullying victimisation as the mediator and mental wellbeing as the outcome: one with a school-level interaction between intervention assignment and the mediator; and one with a random slope component for the student-level mediator-outcome relationship predicted by school-level assignment. We relate each of these models to contextual or individual-level explanations for the healthy context paradox.
Neither model suggested that the INCLUSIVE trial represented an example of the healthy context paradox. However, each model has different interpretations which relate to a multilevel understanding of the healthy context paradox.
Greater exploration of intervention harms, especially when those accrue to population subgroups, is an essential step in better understanding how interventions work and for whom. Our proposed tests for the presence of a healthy context paradox provide the analytic tools to better understand how to support development and implementation of interventions that work for all groups in a population.
Current Controlled Trials, ISRCTN10751359 .
最初在学校层面的欺凌干预中描述了健康背景悖论，它指的是即使干预成功减少了受害，但那些持续经历欺凌的人在心理健康方面仍然存在差异。本研究利用 INCLUSIVE 学校恢复性实践试验的数据，将这一悖论与需要理论化干预发展过程中的潜在危害联系起来；以中介关系和群体水平干预为特征，更一般地表述健康背景悖论；并根据多层次中介方法提出了两种用于检验健康背景悖论的统计模型，这些模型与该悖论的结构和个体解释有关。
我们使用欺凌受害作为中介，心理健康作为结果，估计了两个多层次中介模型：一个模型具有干预分配与中介之间的学校层面交互作用；另一个模型具有学生层面中介-结果关系的学校层面分配的随机斜率成分。我们将这些模型与健康背景悖论的情境或个体水平解释联系起来。
两个模型都没有表明 INCLUSIVE 试验代表了健康背景悖论的一个例子。然而，每个模型都有不同的解释，这些解释与健康背景悖论的多层次理解有关。
更深入地探讨干预的危害，尤其是当这些危害发生在人口亚组时，是更好地理解干预如何起作用以及针对哪些人群的重要步骤。我们提出的用于检验健康背景悖论存在的测试为更好地理解如何支持开发和实施对人群中所有群体都有效的干预措施提供了分析工具。
当前对照试验，ISRCTN86024226。
