• Fitness & Health
• Sport & Exercise Science
• Physical Education
• Strength & Conditioning
• Sports Medicine
• Sport Management
• Dance

Using the evidence pyramid to assess athletic training research

This is an excerpt from Evidence-Based Practice in Athletic Training 2nd Edition With HKPropel Access by Scot Raab,Naoko Giblin.

Review of the Evidence Pyramid

The evidence pyramid was provided in chapter 1 (see figure 1.1). Let’s look at the pyramid in more detail. Each layer of the pyramid represents different study designs that provide a certain level of evidence. The level of evidence is the strength associated with the credibility and generalizability of the evidence. The higher the strength, the higher the level of evidence. When you are reading an article, you should be cognizant of the strength of its evidence. Sitting at the bottom of the ­pyramid are expert opinion articles. They are helpful for gaining a broad ­understanding of a topic from an expert in a specific field; however, they may not be based on strong, unbiased empirical evidence. It is not that expert opinions aren’t important. Rather, they just may not be applicable to the entire population.

The next four study designs of the pyramid represent the next level of evidence known as unfiltered information: case series or reports, case control studies, cohort studies, and randomized controlled trials (RCTs). Unfiltered information consists of primary original research. Unfiltered simply means that the methods are not evaluated piece by piece in combination with other studies and therefore leave more room for bias. Case series and reports help highlight the uniqueness in the presentation of diseases, treatment and management of conditions, and exploration and validation of treatment or management protocols. Case control studies are often retrospective and compare some factors between those who have an outcome of interest (case) and those who don’t (control). An example of a case control study involves investigating the differences in single-leg balance ability between those who have a history of mild traumatic brain injury (case) and those who have never had the injury ­(control). Cohort studies are typically prospective studies, which allow the researcher to track two different groups of different ­characteristics and determine whether their outcomes differ in the future. For example, you would conduct a cohort study if you were studying whether individuals who had previous ACL reconstruction would suffer more anterior knee pain throughout a ­competitive season compared to those who did not have the surgery. RCTs are studies that involve random assignment of the participants into two different groups, one of which is a control group, and follow the outcomes. An example of an RCT is a study that investigates the effects of a six-week ankle proprioception training regimen on vertical jump performance compared to no training. RCTs are excellent resources for informing your clinical practice because they represent individual research studies investigating particular topics. Also, RCTs are stronger than other ­studies because of a smaller likelihood of bias. However, a smaller room for bias does not mean that bias does not exist for RCTs. This is why it is critical for a reader to ­critically appraise any study before deciding to incorporate information from the study into their clinical practice. 

In the upper echelon of the evidence pyramid are three levels of filtered ­information: critically appraised individual articles, critically appraised topics (CATs), and systematic reviews (SRs), which typically include meta-analyses (MAs). Filtered information provides a comprehensive evaluation of a study or a group of studies with a similar topic, with the evaluation performed by someone other than the researchers who conducted the study. These filtered resources are helpful because quality assurance of collective studies is already done for you. The CATs, SRs, and MAs are not intended to replace unfiltered information but rather are meant to assist a reader in determining the appropriate clinical applications within a related topic. For example, you might be interested in the best exercise method for treating individuals with medial tibial stress syndrome (MTSS). Rather than going through the process of searching for individual research studies (unfiltered information such as RCTs or case studies) and evaluating each of them separately, you can read CATs, SRs, or MAs that have collected and evaluated several related studies. Authors of CATs, SRs, and MAs often provide clinical conclusions based on the available evidence, which may help you decide which exercise to implement for your patients. Be careful, however, about how the synthesis and evaluation of collected information have been conducted in the CATs, SRs, and MAs, and understand that your clinical questions may not be fully addressed in the filtered resources. In the next sections, we will discuss more details on filtered resources, including their benefits and limitations in guiding clinical practice. 

Filtered reviews allow clinicians to let statistical experts evaluate research articles around specific areas of interest and provide a summary of results. Our hope is that you will become proficient at finding and interpreting these relevant reviews. To do so, you must have a clear understanding of what each of the three filtered review types offers.

More Excerpts From Evidence-Based Practice in Athletic Training 2nd Edition With HKPropel Access

---