As a clinician, I was always being shown research and opinions on why products were the best. It’s very easy to hear good information, especially when it’s presented by a company talking about their own product line. But not all research is the same, and understanding the difference between a real scientific study and other types of research is key when you are making buying decisions.
There are basically five evidence levels when talking about research. Level 5 would be the least evidence, and level 1 the most evidence:
- Level One Evidence: Randomized controlled trials and systematic review of the randomized controlled trials.
- Level Two Evidence: Cohort/Outcome based studies
- Level Three Evidence: Case-Control Studies
- Level Four Evidence: Case Series/Descriptive Studies
- Level Five Evidence: Editorials/Expert Opinion
You will often see lower levels of evidence, especially editorials and expert opinions. But evidence-based medicine centers on information and evidence from clinical trials and systematic reviews. Expert opinion can be unreliable, as it’s just an opinion and not based on scientific study.
While you are no doubt familiar with evidence levels, a review is always helpful.
Here is a brief definition of some of the evidence levels:
A randomized controlled trial is a type of scientific (often medical) experiment which aims to reduce bias when testing a new treatment. The RCT is often considered the gold standard for a clinical trial.
Outcomes research is applied to clinical situations, and identifies shortfalls in practice and develop strategies to improve care.
A case control study compares patients who have a disease or outcome of interest (cases) with patients who do not have the disease or outcome (controls).
A case series is a type of medical research study that tracks subjects with a known exposure, such as patients who have received a similar treatment, or examines their medical records for outcomes.
An expert opinion is from a person who has special knowledge of a subject that is not possessed by the average person. Expertise may be acquired by experience, education or observation.
When talking to anyone presenting research, it’s important to ask specific questions about what they are presenting. A good example of this is when you are reviewing the adoption of new products based on research. You can specifically ask what level of research they put their products through. But, if they are not sure, you ask specific questions:
- Which medical institution sponsored your research/study?
- What researchers (names of clinicians) were involved in your research/study?
- How long was the study (dates)?
- How many patients/products were in the study?
- Who reviewed your study and the outcomes?
- What were the clinical findings of the research?
- What journals was your study published in?
By asking simple questions, you can easily understand the level of research done on a company’s product. This is important when making decisions on products based on research, as you’ll be using them on your patients.
Remember, just like all products are not the same, the same goes for research, and finding the best for your practice is about understanding and asking the right questions.