What types of interventions reduce or worsen inequalities in adolescent smoking? A review of the literature and reanalysis of intervention studies.

在包括英国在内的许多发达国家，随着社会经济地位（SEP）的提高，健康结果显著改善。低SEP个体中较差的健康行为加剧了这些不平等。特别是，虽然近年来吸烟率有所下降，但在低SEP人群中吸烟仍然更为普遍。大多数吸烟发生在青少年时期（每9名英国青少年中就有1人在15岁之前每天吸烟），社会经济不平等在青少年时期出现，直到成年。因此，采取行动减少青少年吸烟方面的不平等可能在减少不平等方面发挥至关重要的作用。关于何种行动可能增加或减少卫生不平等现象的辩论越来越多。许多人从社会生态理论或根本原因理论等角度认为，基于教育或个人选择的干预可能会扩大不平等，而针对更多结构性因素（如定价和可获得性）可能会减少不平等。然而，目前这些命题的经验证据有限，因为很少有研究分析SEP的影响，或者试图确定哪些类型的行动在什么情况下减少或增加了现有的不平等。该研究将包括对目前发表的证据进行审查，以证明这种干预对不平等现象的影响，并对收集SEP测量的已发表研究进行重新分析。第一阶段将主要是描述性的，旨在检查在设计减少青少年吸烟的评估和干预措施时考虑到社会经济不平等的程度。将对一系列数据库进行系统搜索，以确定自世纪之交以来发达国家进行的干预研究。在这些研究中，差异有效性检查的普遍程度和方式（例如，是否通过亚组分析，使用相互作用术语，或针对低SEP群体的干预措施）将被检查。还将审查干预发展中对青少年吸烟不平等的影响有多普遍，以及以何种方式考虑。在干预和评估设计中考虑对不平等影响的程度和性质将在干预类型（即个人层面、社区层面或社会层面的干预）之间进行比较。收获地块方法将用于结合研究，检查不同程度的干预对社会经济不平等的影响。将编制收集SEP测量的研究数据库，并根据干预类型、研究质量和国家对研究进行标记。在第二阶段重新分析的研究将从该数据库中取样。第二阶段将旨在通过重新分析收集SEP测量的干预研究数据集，提高我们对各种公共卫生干预措施对社会经济不平等的影响的理解。将从第一阶段开发的数据库中选择多达40项研究，代表一系列i)个人，ii)社区，iii)社会和iv)来自一系列发达国家的多层次干预措施。将通过电子邮件联系通讯作者，询问是否进行了未发表的差异有效性分析，如果有，他们是否愿意分享这些分析。如果他们没有，作者将被要求提供原始数据，这些数据将由SEP重新分析差异有效性，或者进行重新分析并提供语法和日志文件。然后将收获地块扩展以纳入这些额外的分析，并在可行的情况下使用荟萃分析结合效果。该研究将为政策制定者提供有关其行为如何影响不平等的信息，推进减少不平等的社会科学理论，并强调以捕捉对不平等影响的方式设计评估的重要性。

In many developed countries including the UK, health outcomes improve significantly as socioeconomic position (SEP) increases. Poorer health behaviours among lower SEP individuals contribute to these inequalities. In particular, while smoking rates have fallen in recent times, smoking remains more common among lower SEP individuals. Most smoking uptake occurs in adolescence (1 in 9 English adolescents are daily smokers by age 15), with socioeconomic inequalities emerging in adolescence before tracking into adulthood. Hence, action to reduce inequalities in adolescent smoking may play a vital role in reducing inequality. There is increasing debate regarding what types of actions might increase or decrease health inequalities. Many argue from perspectives such as socio-ecological theory or the theory of fundamental causes, that interventions based upon education or individual choice may widen inequality, while targeting more structural factors, such as pricing and availability may reduce inequality. However, there is currently limited empirical evidence for these propositions, as few studies have analysed effects by SEP, or attempted to identify what types of actions reduce or increase existing inequalities, in what contexts. The study will involve a review of current published evidence for impacts of such intervention on inequalities and reanalysis of published studies which collected measures of SEP. Phase 1 will be largely descriptive and will aim to examine the extent to which socioeconomic inequalities have been considered in the design of evaluations and interventions to reduce adolescent smoking. Systematic searches of a range of databases will be used to identify intervention studies in developed countries since the turn of the century. How commonly, and in what ways, differential effectiveness was examined (e.g whether via subgroup analysis, use of interaction terms, or targeting of interventions toward lower SEP groups) within such studies will be examined. How commonly, and in what ways, impacts on inequalities in adolescent smoking are considered in intervention development will also be examined. The extent and nature of consideration of impacts on inequality in intervention and evaluation design will be compared across intervention types (i.e individual level, community level, or society level intervention). Harvest plot methodology will be used to combine studies which examine impacts of different levels of intervention on socioeconomic inequality. A database of studies which collected measures of SEP will be compiled, with studies labelled according to intervention type, study quality and country. Studies to be reanalysised in Phase 2 will be sampled from this database. Phase 2 will aim to advance our understandings of the impacts of various types of public health interventions upon socioeconomic inequalities through reanalysis of datasets from intervention studies which collected measures of SEP. Up to 40 studies will be selected from the database developed during Phase 1, representing a range of i) individual, ii) community, iii) society and iv) multi-level interventions from a range of developed countries. Corresponding authors will be contacted by email and asked whether any unpublished analyses of differential effectiveness were conducted, and if so, if they are willing to share these. Where they were not, authors will be asked to supply original data, which will be reanalysed for differential effectiveness by SEP, or to conduct reanalysis and supply syntax and log files. The harvest plot will then be extended to incorporate these additional analyses, with effects combined using meta-analysis where feasible. The study will provide policymakers with information on how their actions might impact inequalities, advance social science theory for reducing inequalities, and highlight the importance of designing evaluations in a manner which captures impacts on inequality.