膳食参考摄入量(DRI)是为国家营养政策提供信息的基础。然而,对51种具有DRIs的营养素进行定期系统审查的可行性有限,许多DRIs尚未在15年进行审查。
为了解决这个问题,食品和营养委员会成员的个人(营养素审查小组)制定了一个精简的,基于证据的方法,可用于确定可能需要系统审查的营养素。
提出的方法,称为证据扫描,包括几个步骤。首先,建立了一个分析框架来确定营养素摄入量与相应临床结局之间的关联指标.接下来,该框架用于指导关键词的识别,以扫描已发表的研究,这些研究可能与营养素的摄入量要求或较高摄入量相关。最后,内容专家小组选择可能相关的摘要,并审查完整的出版物。结果可用于确定营养素DRI的修订是否是当务之急,但不会取代全面的系统证据审查。
为了说明这个过程,选择了2种营养素作为案例研究:硫胺素和磷(DRI的最后一组分别是1998年和1997年)。使用硫胺素的证据扫描,我们确定了70篇潜在的相关摘要,其中9份完整出版物进行了审查。对于磷,确定了127份潜在相关摘要,审查了29份完整的出版物。
从这两种营养素的回顾来看,营养审查小组的结论是,没有足够的新证据将硫胺素或磷的全面系统审查置于高度优先地位.证据扫描是识别最需要新的或更新的系统评价的DRI营养素的有效方法。
Dietary Reference Intakes (DRIs) are fundamental to inform national nutrition policy. However, a regular systematic review of the 51 nutrients that have DRIs has limited feasibility, and many DRIs have not been reviewed in >15 y.
To address this issue, individuals (nutrient review group) who were members of the Food and Nutrition Board developed a streamlined, evidence-based methodology that could be used to identify nutrients potentially in need of a systematic review.
The proposed methodology, termed an evidence scan, comprises several steps. First, an analytic framework is developed to identify markers of associations between intake of a nutrient and a corresponding clinical outcome. Next, the framework is used to direct the identification of keywords for a scan of published research that is potentially relevant to intake requirements or upper intake levels for a nutrient. Last, a panel of content experts selects the abstracts that are likely to be relevant and reviews the full publications. The results may be used to determine whether a revision of the nutrient\'s DRI is an immediate priority but would not supplant a comprehensive systematic evidence review.
To illustrate the process, 2 nutrients were selected as
case studies:
thiamin and phosphorus (DRIs were last set in 1998 and 1997, respectively). Using the evidence scan for
thiamin, we identified 70 potentially relevant abstracts, of which 9 full publications were reviewed. For phosphorus, 127 potentially relevant abstracts were identified, and 29 full publications were reviewed.
From the review of these 2 nutrients, the nutrient review group concluded that there was insufficient new evidence to assign a high priority to a comprehensive systematic review for either
thiamin or phosphorus. Evidence scanning is an efficient method of identifying DRI nutrients that are most in need of either a new or an updated systematic review.