(P11-022-24) Challenges in Appraising Nutrition Evidence: A Scoping Review

Objectives: Evidence-based decision-making necessitates evaluation of the certainty (quality) of evidence. We present a scoping review describing challenges in appraising nutrition evidence.

Methods: We searched MEDLINE, EMBASE, and Web of Science, from inception to December 2023, for articles describing challenges in evaluating or interpreting nutrition evidence. Reviewers worked independently and in duplicate to screen references and to collect data from eligible publications.

Results: Our search yielded 2,235 unique records, of which 63 proved eligible. We identified several challenges, one of which we describe in this abstract as an example.

One particularly contentious issue is the interpretation of non-randomized evidence. In most health fields, randomized trials offer higher certainty evidence, because, by virtue of randomization, they achieve balance in prognostic factors such that any observed difference in outcomes between randomized arms can be confidently attributed to the intervention under study. The evidence addressing the health effects of dietary exposures, however, comes primary from observational nutritional epidemiology studies, in which observed associations between diet and health may be confounded by other factors that are correlated with diet and that may also influence health.

Some investigators argue that dietary randomized trials are not feasible and so non-randomized studies should be given more weight. Conversely, others argue that the challenges of conducting randomized trials should not increase our confidence in non-randomized studies. These investigators also argue that there are compelling reasons for maintaining similar standards for evaluating evidence across health fields. Clinicians, patients, and decision-makers weigh the benefits and harms of many kinds of interventions—pharmacological, surgical, and nutritional—for a clinical or public health problem. Using modified criteria to assess the certainty of evidence for some interventions and not others would be misleading.

Conclusions: Nutrition investigators and decision-makers disagree about fundamental considerations related to evaluating the certainty of evidence. There is an urgent need to achieve consensus on criteria for evaluating the certainty of nutrition evidence.

Funding Sources: None