Due to the challenges of conducting randomised controlled trials (randomised trials) of dietary interventions, evidence in nutrition often comes from non-randomised (observational) studies of nutritional exposures—called nutritional epidemiology studies. When using systematic reviews of such studies to advise patients or populations on optimal dietary habits, users of the evidence (eg, healthcare professionals such as clinicians, health service and policy workers) should first evaluate the rigour (validity) and utility (applicability) of the systematic review. Issues in making this judgement include whether the review addressed a sensible question; included an exhaustive literature search; was scrupulous in the selection of studies and the collection of data; and presented results in a useful manner. For sufficiently rigorous and useful reviews, evidence users must subsequently evaluate the certainty of the findings, which depends on assessments of risk of bias, inconsistency, imprecision, indirectness, effect size, dose-response and the likelihood of publication bias. Given the challenges of nutritional epidemiology, evidence users need to be diligent in assessing whether studies provide evidence of sufficient certainty to allow confident recommendations for patients regarding nutrition and dietary interventions. Data sharing not applicable as no data sets generated and/or analysed for this study.

中文翻译：

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营养用户指南：系统评价第 1 部分——非随机营养流行病学研究的系统评价和荟萃分析的方法学评估、解释和应用的结构化指南


由于进行饮食干预的随机对照试验（随机试验）的挑战，营养方面的证据通常来自营养暴露的非随机（观察）研究，称为营养流行病学研究。当使用此类研究的系统评价来建议患者或人群最佳饮食习惯时，证据的使用者（例如临床医生、卫生服务人员和政策工作者等医疗保健专业人员）应首先评估证据的严谨性（有效性）和实用性（适用性）系统审查。做出这一判断的问题包括审查是否解决了合理的问题；包括详尽的文献检索；谨慎选择研究和收集数据；并以有用的方式呈现结果。为了进行足够严格和有用的审查，证据使用者必须随后评估研究结果的确定性，这取决于对偏倚风险、不一致、不精确、间接性、效应大小、剂量反应和发表偏倚可能性的评估。鉴于营养流行病学的挑战，证据使用者需要勤于评估研究是否提供足够确定性的证据，以便为患者提供有关营养和饮食干预的自信建议。数据共享不适用，因为本研究没有生成和/或分析数据集。