An evaluation of the recommendations for primary nutrition research addressing noncommunicable disease using the EPICOT+ framework: A cross-sectional descriptive meta-research study of Cochrane nutrition systematic reviews

Background

Noncommunicable diseases (NCDs) are a global health problem and many risk factors associated with the development of NCDs are related to nutrition.

Aims

This study aimed to describe and summarize the research recommendations for primary research made in Cochrane nutrition systematic reviews (SRs) addressing NCDs, according to the evidence, population, intervention, comparison, outcome, time stamp (date of search), study design, time frame (length of follow-up) and burden of disease (EPICOT+) framework.

Materials & Methods

We screened a database of Cochrane nutrition SRs (n = 692) in March 2021 to identify those SRs addressing the four main NCDs (cardiovascular diseases, cancer, chronic respiratory diseases, and diabetes) and their nutrition-related risk factors (obesity, unhealthy diets). The “implications for research” sections of included SRs (and the “search methods” sections for the time stamp item) were analyzed using EPICOT+.

Results

We included 150/692 SRs; most addressed cardiovascular diseases (38.6%), and cancer (17.3%). The EPICOT+ items with the most reported research recommendations were time stamp (98.7%), intervention (94.7%), study design (89.3%), and outcomes (86%), and the least reported were the time frame (52%), comparison (30%), and burden of disease (8%). Most SRs recommended more studies overall (98.7%), assessing specific interventions (93.3%) (e.g., specific foods/food groups and diets/dietary patterns, micronutrient/complementary supplements, nutrition education techniques, and policies/programs) and a range of clinical and patient-related outcomes (84.7%). Recommendations related to study design and quality included the need for more randomized (72.7%), better quality (55.3%), larger (44.7%), and better reported (26%) studies with a long-term duration of follow-up (50.7%).

Discussion

Our findings show that research recommendations reported in Cochrane nutrition SRs addressing the four major NCDs and their nutrition-related risk factors largely followed the EPICOT+ framework. For example, items that could be improved upon were the comparison and time frame items.

Conclusion

These recommendations could contribute more significantly to planning future primary studies addressing important evidence gaps and limitations in the current evidence base.