Evaluating Medical Research

Evaluating Medical Research

Medical research varies in quality. Some studies are well thought-out and interpreted, and some are not.

There are several things to look at when reading a study:

• Is it asking the right question? In scoliosis, your question might be "How will I feel 20 years after a surgery," but the study might only be asking "How many people required revision surgery." That's part of the answer to how you might be feeling, but it doesn't tell you, for example, how many people did not have surgery but have significant pain that they're dealing with by taking pain medicine. So, focus on what's important to you and decide how well the study addresses that concern.
• Is it designed to answer the question that it's asking? Looking at surgery outcomes again, many studies equate "amount of correction" and "success". So, when trying to find out if surgery is successful, they ask what the degree of correction in Cobb angle was. As a patient, your view of success is going to be broader and include things like pain, function, etc. So, make sure that the study isn't trying to answer a question that it's not designed to answer.
•  How many and what type of patients were included? In general, the more patients, the more likely that the study is generalizable. And, the more the patients are like you, the more likely that the results will apply to you. For example, if you have a teenager going into surgery, a small study of how adults over 30 respond to surgery is probably not relevant for you.
• What is the quality of the evidence? Medical research is graded by the type of study design - some designs are simply better then others. If you're looking at research, look first for the one with the highest-quality design and the most participants.
  
  Designs are graded as follows (from Wikipedia)
  
  

  "US Preventive Services Task Force (USPSTF)[edit]

  Systems to stratify evidence by quality have been developed, such as this one by the U.S. Preventive Services Task Force for ranking evidence about the effectiveness of treatments or screening:^[30]
  • Level I: Evidence obtained from at least one properly designed randomized controlled trial.
  • Level II-1: Evidence obtained from well-designed controlled trials without randomization.
  • Level II-2: Evidence obtained from well-designed cohort or case-control analytic studies, preferably from more than one center or research group.
  • Level II-3: Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled trials might also be regarded as this type of evidence.
  • Level III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees."