When you put yourself – and your body – in the hands of a doctor, you want to be sure that they are using reputable science when they make treatment decisions. Many different medical publications exist, each publishing a variety of articles and medical studies.
It can be hard to know which studies are best, especially if they reach different conclusions. Similarly, it can be difficult to know if you can trust claims on over-the-counter supplements or other medical products that say they are clinically proven, or claims from a friend who tells you that a certain treatment works well.
In the medical field, doctors are trained to evaluate medical claims using the principles of evidence-based care.
What Is Evidence-based Medical Care?
Evidence-based care relies on peer-reviewed studies. This means that the studies are not only conducted by experts, but that the studies are then reviewed by other experts in the field to ensure that the study was properly conducted.
This process is important to make sure that people get high-quality medical recommendations, as opposed to recommendations that are backed by minimal evidence.
Evidence-based Care Hierarchy
Evidence-based care also sorts peer-reviewed medical studies into a hierarchy, dividing them into groups. Each group is then ranked by its reliability. These classifications help both doctors and patients get an idea of how trustworthy the source is. The hierarchy is as follows:
Systematic Reviews and Meta-Analyses
Systematic reviews and meta-analyses are considered to be the best level of evidence.
In a systematic review, a researcher doesn’t conduct their own study. Rather, they evaluate a group of credible studies that have been conducted on a medical topic. By putting together and analyzing these studies, they can draw conclusions about the evidence.
A meta-analysis often accompanies a systematic review. A meta-analysis pools the statistical data from the studies in the systematic review.
With a large data set from multiple studies, the meta-analysis and systematic review can draw conclusions about optimal medical care.
For example, The Spine Journal published a systematic review and meta-analysis showing that chiropractic care is effective for treating low back pain.
Clinical Guidelines
Clinical guidelines are written by panels of subject matter experts in a particular field. Together, they evaluate studies and use their expertise in their field to draw conclusions about best practices when it comes to patient care.
The experts then make specific recommendations about the topic based on the best science available. Generally, experts go one step further and rank the existing science, stating whether the available science is strong, moderate, low, or very low in quality.
Further, based on their confidence in the benefits of the existing science, experts will state that their recommendations are either strong or weak. Often, professional societies or journals in a specific field of medicine will sponsor and publish guidelines: for example, the Journal of Manipulative and Physiological Therapeutics published a clinical guideline of chiropractic care for low back pain.
Randomized Controlled Trials
Randomized controlled trials are among the most well-known, and highest-quality, types of studies available. In randomized controlled trials, participants in the study are randomly assigned to different treatment groups. Each group then gets a different medical intervention, and the results are compared.
Randomized controlled trials are considered to be the gold standard among studies because, being randomized, they minimize the risk of bias, or skewed results, in studies. By randomly assigning participants in the study to different therapies, randomized controlled trials minimize the risk of selection bias, in which one group of people might be more likely to receive treatment.
For example, if demographics like age are not equal between the treatment groups, then it is harder to attribute any differences in outcome to the treatment alone because age could also be a factor. For this reason, unlike other types of studies, randomized controlled trials can prove cause-and-effect.
Some randomized controlled trials go several steps further. Many randomized controlled trials are blinded, or single-blinded, meaning that the participants do not know what treatment they are receiving.
Other studies are termed double-blinded, meaning that neither the participants nor the researchers know what treatment the patient is receiving. An example of a single-blinded randomized controlled trial for chiropractic care is a study published in BMC Research Notes which supported the safety of chiropractic care for cervicogenic headache.
Notably, although randomized controlled trials are excellent for evaluating common conditions, it is less feasible to use them for rare conditions because they require large participant groups.
Cohort Studies
Cohort studies are longitudinal studies, meaning that they take place over a period of time.
Unlike randomized controlled trials in which participants are often demographically dissimilar, in a cohort study, participants are selected because they share certain characteristics. Also unlike randomized controlled trials, they are not used to show cause and effect.
Instead, because cohort studies can take place over the course of many years, they are useful in helping doctors determine what factors in a person’s life may cause, or protect against, disease.
For example, in a cohort study published in the Journal of Manipulative and Physiological Therapeutics that supported chiropractic care for neck pain, participants were enrolled into the cohort if they had a history of neck pain.
Case-Control Studies
Unlike randomized controlled trials and cohort studies, which recruit participants and prospectively follow them forward in time, case-control studies look back into the past. As such, they are termed retrospective studies.
In case-control studies, “cases” are a group of people known to have a certain health outcome, such as stroke. They are then compared against “controls,” a group of people who are known to be free of the health outcome.
Researchers then look back in time and evaluate factors that might have contributed to the health outcome. A recent case-control study for chiropractic care, for example, found that there was no link between chiropractic care and a certain type of stroke, supporting the safety of spinal manipulation.
Case Series and Case Reports
Similar to case-control studies, case series and case reports look back in time. They are among the smallest studies that can be conducted: a case report, for example, is usually a report about a health outcome in a single patient.
Likewise, a case series looks at several patients with a certain health outcome. In both case series and case reports, the patient’s medical history is analyzed for relevant factors that might have led to the health outcome.
As such, both case series and case reports can be used to generate a hypothesis that can later be tested in other studies. One case report relevant to chiropractic care was published in the Journal of the Canadian Chiropractic Association. It discussed a woman with neck pain, temporomandibular joint syndrome, and trigeminal neuralgia whose pain significantly improved with long-term chiropractic care.
Animal Studies
Animal studies have some of the lowest quality of evidence in comparison to other studies. While some treatments that are tested in animals later have success when tested in humans, others do not.
The extent to which a promising study in animals translates to humans can be unpredictable because humans and animals have such different physiologies. As a result, few medical professionals will rely on animal studies when making healthcare recommendations.
In Vitro or Lab Tests
In vitro and lab tests are considered the lowest quality of evidence. Unlike research that involves living beings, termed in vivo research, in vitro research often takes place entirely in a lab, sometimes using human cells. Although in vitro and lab testing is a simple concept, it can be hard to extrapolate results from a lab to real-world results in a living organism.
Evidence-based Care and NUCCA Chiropractic
At Precision Spinal Care, I use evidence-based care when coming up with all of my treatment plans. To provide the best care possible, I stay up to date on the most recent evidence-based medical plans as relates to chiropractic care. Further, I will discuss my assessments with you, answering all of your questions after a thorough examination.
If it is determined that chiropractic is not the best solution, I will explain your condition and recommend the type of specialist who is most appropriate for you.
We understand that you need to explore all your options when you look for expert chiropractic care. At Precision Spinal Care, we are happy to help you determine the best way to address your specific needs and discuss all the options with you and your family.
Contact our office or call us at (757) 382-5555 to speak to the doctor or set up a consultation.
