Fig 1.
Nutrition topics included in systematic reviews conducted by three organizations.
Fig 2.
*Publication years were selected based on decades prior to reporting guidelines (<1900 and 1900–1999), decade of implementing publication guidelines (2000–2009), and after implementation of publication guidelines (2010–2015). AHRQ, Agency for Healthcare Research and Quality; RCT, randomized controlled trial.
Fig 3.
Mapping critical appraisal items to risk of bias domains.
Fig 4.
Distribution of sample of critical appraisal records.
*Critical appraisal records for research articles included in systematic reviews in each system. A single article may have critical appraisal records in more than one AHRQ report or records within more than one system.
Table 1.
Characteristics of food and nutrition research used in systematic reviews.
Fig 5.
Research design types by source of funding.
CT, controlled trial; RCT, randomized controlled trial.
Table 2.
Summary of significant relationships between overall quality and ROB domain ratings by research typea.
Table 3.
Final models for predicting ROB Being met in studies with interventional designs by funder and research type and design: separate models for ROB domains.
Table 4.
Final models for predicting ROB being met in studies with observational designs by funder and research type and design: separate models for ROB domains.
Fig 6.
Significant relationships between risk of bias* and funder, research design, and year by research type.
*Arrows indicate statistically significant differences from the reference category (p < .0005, Bonferroni correction applied). Downward arrows indicate a lower risk of bias and an upward arrow represents a higher risk of bias.