In the name of science applied to health and based on it, we always seek to make the best decisions, reduce uncertainty, error and, of course, give the most accurate information to the entire population. However, and although this is desirable, it does not always happen, either due to the absence of scientific studies, its light reading or its inadequate interpretation. This paper presents an easy guide to interpret the results of scientific studies in health.
Types of scientific studies in health
In order to facilitate the interpretation of all scientific studies in the field of medicine and human health, four large groups can be found:
- Animal studies
- Descriptive or observational studies in humans
- Experimental studies in humans (clinical trials)
- Studies of more studies, known as reviews
Each of these types of studies has a particular purpose and serves different purposes. Thus, things cannot be interpreted in a similar way. Hence the importance of knowing them properly understand their limitations, strengths and usefulness.
Good practices when analyzing results of health studies
First, it is important to analyze the characteristics of the different types of research that are commonly used in health research:
Animal studies. It is important to keep in mind that these investigations are carried out because it is expected to obtain from them information that could not be obtained in any other way and that benefits many people in the future. When these studies are carried out they are always executed with strict norms that limit and control their suffering. Animal studies are used to evaluate causes of the disease, disease mechanisms and the first phases of study of efficacy and safety of medications. That is, animal studies allow us to begin understanding the disease and how medications could work. However, and it is important to keep it in mind, not always what happens in an animal model necessarily occurs in the same way in human beings.
Descriptive or observational studies in humans. As the name implies, they are studies that are carried out in humans, but they are merely dedicated to describing or looking for relationships and associations between variables based on the observation of parameters in people (there is no intervention on treatments or behaviors in people). Survey studies or association studies such as those that allowed cholesterol levels to be related to heart attacks. These studies allow to find relationships and associations between variables, but they do not allow, in general terms, to determine a cause-effect relationship with accuracy. These studies are very useful to investigate factors related to the development of the disease, the behavior of diseases or the way in which people behave in a treatment.
Experimental studies in humans (clinical trials). To be sure of the effectiveness of the treatments, studies in humans are designed and executed in a way that controls how it is delivered and compares against other treatments and against placebo. Placebo is a control treatment that does not contain medication, but it looks, tastes and smells similarly. Control against placebo is important because any type of intervention always produces an effect and a medication with a real effect must produce an effect superior to this. These types of studies are considered the most important in determining the real efficacy of medications. The value of these types of studies is that they are considered of high value to determine if a medication or intervention is useful for the treatment of a disease with a low level of error or uncertainty.
Studies of more studies, known as reviews. There are two types of reviews, some known as narratives are those that give an overview (a kind of theoretical framework) on a topic. Other reviews are known as systematic and these are usually combined with statistical techniques (meta-analysis) and generally include clinical trials evaluating a medication or intervention. These systematic reviews are considered as studies of great value in the evaluation of efficacy (that is, whether or not it serves) a medication or intervention.
The following are considered good practices when making health reports
Since each study provides a different knowledge, to avoid misinterpreting the results of the studies it is important to take into account certain elements of them to avoid transmitting the information in a wrong way:
- Report the magazine and the year in which the research was published. Review directly in the magazine that the work has indeed been published.
- Observe the type of study in question and its objective. In any scientific study in the summary, introduction section and methods this information is presented clearly and appropriately.
- Review the limitations of the study. In the penultimate and last paragraph of scientific articles, researchers often discuss the limitations of their own work. This helps to understand the real dimension that the results of the study can have.
- Resize the conclusion. In the last paragraph the group of authors of a research exposes what may or may not be concluded, from their perspective, of the research. This information generally expresses well the dimension of the research results. In many cases this may even be less impressive than initially thought.
- Repeat. It is always important to answer the following question: Are these results similar to those reported in other investigations? When the findings of an investigation have been repeated by other groups and through other investigations they are more likely to have a greater degree of certainty.
In our next installment, advice will be given to achieve the proper reading of a scientific study in health.
If you liked this article we invite you to share it and subscribe in the “Newsletter” link to receive more information and related content.
- Pita Fernández. Types of clinical epidemiological studies. Fisterra 2001;
- Okuda Benavides, Mayumi Gómez Restrepo C. Research Methodology and Critical Reading of Studies. Rev Colomb Psychiatr. 2005;
- Hernández R, Fernández C, Baptista P. Research methodology. Journal of Chemical Information and Modeling. 2014.
- Parascandola M, Weed DL. Causation in epidemiology. J Epidemiol Community Health. 2001;
- Kundi M. Causality and the interpretation of epidemiologic evidence. Environmental Health Perspectives. 2006