Real World Evidence Versus Randomised Controlled Trials: Is the Future of Nutritional Sciences Research in Electronic Health Records?

Randomised controlled trials (RCTs) are the gold standard of research studies. They aim to recruit participants with similar characteristics and randomly assign them to a treatment or control/placebo arm. Due to randomisation, RCTs provide comprehensive, unbiased evidence about treatment efficacy and safety and examine cause-and-effect relationships between the intervention and outcome. However, RCTs are expensive, recruitment can be time-consuming and high drop-out rates can reduce internal validity. Depending on the target population, findings are not always generalisable at a population level. Of relevance to nutritional sciences, due to the type of research questions, researchers and participants cannot always be blinded to randomisation. Electronic health records (EHRs) provide a possible solution to some of these constraints. Using data from healthcare systems may help to reduce costs and overcome logistical challenges as (1) pragmatic trials integrated into routine care enable real-time data analysis and faster translation of findings and (2) once dynamic longitudinal cohorts have been generated, they can be analysed using quasi-experimental designs. These have the potential to provide population level data with higher generalisability, lower attrition and greater statistical power. EHRs do come with their own challenges, including the lack of a uniform information infrastructure, missing data and data quality. There are also ethical considerations, as patients may not wish for their data to be used in a research capacity, which in turn can affect the generalisability of findings. When it comes to nutritional sciences and generating evidence, there is no one-size fits all approach. EHRs offer great potential for advancing certain research questions, such as when there is a population level intervention, for example, the soft drinks industry levy or the inclusion of folic acid in non-wholemeal wheat flour. EHRs offer the opportunity to integrate multiple datasets which will enable a comprehensive understanding of a nutrition intervention impact on health and disease in diverse populations and real-world settings. However, RCTs remain imperative for understanding causality. The scope of this review is to examine how RCTs and EHRs can be used to generate evidence in nutritional sciences, highlighting their respective opportunities and challenges.