Post 1: Can we believe what we read?

When we see health reports on television, in magazines or in a brochure, it is difficult to know where the information is coming from.  Who provided the information, is the source credible, who did the study, is there any bias, is it consistent with other research?   

Most of the nutritional health information we are exposed to comes from epidemiologic research but knowing if the information can be trusted is difficult. Nutritional epidemiology studies the relationships between food and health, looking at dietary exposures and health outcomes.  While often difficult to prove causal associations, nutritional epidemiology plays a key role in health planning and prevention¹.   

With media misreporting rife in the quest for sensationalist headlines or to simply fit editorial space, these are all the more reasons to be asking the important questions to help sift through dubious 'facts'. 

Image 1: Medical Journal cartoon

Over the next few blogs, we’ll explore the world of health research and offer a guide to understanding and navigating study design.  

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1  Byers T. The role of epidemiology in developing nutritional recommendations: past, present, and future. Am J Clin Nutr. 1999; 69(6);1304s-1308s

Post 2: Types of study design

When people read about a health research study, they may not pay attention to how the study was designed. But to understand the quality of the findings, it's important to know a bit about study design. 

According to the widely accepted hierarchy of evidence (refer Figure 1), most of the health research that makes news headlines can be broken down into two basic types: observational and experimental.   

Observational studies involve observing and gathering data on existing phenomenon and, without any interventions or changes, descriptive information on habits, beliefs and outcomes are gathered.  Observational research produces evidence of correlations, which can be used to make predictions¹.  On the other hand, with experimental research, studies can include interventions to find cause and affect relationships, which are generally considered to be more reliable and trustworthy, and allows us to analyse systems and how they interact¹.   

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1 Ho PM Peterson PN Masoudi FA. Key issues in outcomes research. Circulation.    2008;118:1675-1684