Medical and pharmaceutical science is essential for improving our health. However, decisions on what should be recommended, prescribed, or approved are not always simple. To ensure that treatments work effectively and are safe, various types of studies are conducted. These studies vary in method, accuracy, and purpose. Below, we explain in simple terms the main types of scientific studies and their role in medicine.

Scientific Studies: What Are They and How Do They Work?

There are different types of studies that scientists use to test medications, treatments, and new therapies. These studies help answer important questions such as: "Does this medicine really work?", "Is it safe?", or "What is the best way to treat a disease?"

Here, we will explain the most common types of scientific studies and how they fit into the decision-making process in medicine.

1. Reviews and Meta-Analyses: Gathering Wisdom

Narrative Review

This type of study gathers information from various articles on a topic. However, it does not have a strict selection criterion, which means it may lack precision. It is more a way to summarize what has already been researched on a particular subject.

Source: "The Cochrane Collaboration" – to understand how reviews work in health (www.cochrane.org).

Systematic Review

Different from the narrative review, here researchers follow a rigorous method to select the studies to be analyzed. They seek to gather all relevant studies on a topic and conduct a more detailed analysis, ensuring that the review is more reliable.

Source: "Cochrane Handbook for Systematic Reviews" – manual for conducting well-done systematic reviews.

Meta-Analysis

It is the most robust review. Instead of just summarizing the studies, it combines data from various researches to draw stronger and more reliable conclusions. A well-done meta-analysis is highly respected in the scientific community.

Source: "Meta-analysis in Medical Research" – to understand how meta-analysis is used (www.ncbi.nlm.nih.gov).

2. Observational Studies: When Science Observes the Real World

Cohort Studies

These studies follow groups of people over time. For example, they may observe patients taking a certain medication and compare them with others who do not, to see how the disease develops in each group.

Source: "Cohort Studies in Medicine" – definition and examples of cohort studies (www.bmj.com).

Case-Control Studies

In these studies, researchers compare people who have a disease (the "cases") with others who do not (the "controls"). The goal is to identify factors that may be associated with the development of the disease.

Source: "Case-Control Studies" – explanation of case-control studies in the context of diseases (www.ncbi.nlm.nih.gov).

Cross-Sectional Studies

These studies take a "snapshot" of reality. They analyze data from a group of people at a specific moment, without following the group over time.

Source: "Cross-sectional Studies in Epidemiology" – cross-sectional study in the epidemiological context (www.cdc.gov).

3. Experimental Studies: Testing Treatments in a Controlled Manner

Randomized Controlled Trials (RCTs)

RCTs are considered the "gold standard" of scientific studies. In this type of study, participants are randomly divided into groups. One group receives the treatment or medication, while the other receives a placebo (ineffective treatment). This helps ensure that the results are reliable and not influenced by other factors.

Source: "Randomized Controlled Trials (RCTs)" – detailed explanation of RCT and its importance (www.nice.org.uk).

Double-Blind Trials

In double-blind trials, neither the participants nor the researchers know who is receiving the real treatment or the placebo. This eliminates any bias (personal influence) and helps ensure that the results are more impartial.

Source: "Double-Blind Study" – definition and importance of double-blind trials (www.ncbi.nlm.nih.gov).

Triple-Blind Trials

Similar to double-blind trials, but in this case, even the data analyst does not know who received the treatment or the placebo. This makes the study even more impartial.

Source: "Triple-Blind Studies" – understanding triple-blind trials (www.theclinicaltrialsguru.com).

4. Laboratory Studies: The Initial Phase

Before testing a medication on people, many studies start in laboratories, with cells or animals. In vitro studies test substances on cells, and in vivo studies test on animals. These phases help understand how a medication may react in the human body before being tested on people.

Source: "In Vitro vs In Vivo Studies" – explanation of in vitro and in vivo studies (www.ncbi.nlm.nih.gov).

The Importance of Double-Blind and Triple-Blind Studies

Double-blind and triple-blind studies are highly respected for eliminating bias. When a study is double-blind, neither the researcher nor the participant knows who is receiving the real treatment or the placebo. This reduces the risk of external influences and ensures that the results are as reliable as possible.

In triple-blind trials, the level of impartiality is even higher, as even the data analysts do not know who received the treatment or the placebo. These studies are very important as they help ensure that the results are not influenced by biases or expectations.

What is the "Top 1" to Support Medical and Pharmaceutical Decisions?

The gold standard of medical science is Randomized Controlled Trials (RCTs) and Meta-Analyses of RCTs.

Why?

✔️ Eliminate as much bias as possible.
✔️ Directly test the treatment's effectiveness in humans.
✔️ Use control groups and randomization, making the results more reliable.
✔️ When combined in a meta-analysis, they generate very strong evidence.

If a medication or treatment has been tested and approved in a well-done RCT with a confirming meta-analysis, the scientific community considers this a great basis for guiding medical and regulatory decisions.

Sources Used:

The Cochrane Collaboration – www.cochrane.org
Cochrane Handbook for Systematic Reviews – www.cochrane.org
Meta-analysis in Medical Research – www.ncbi.nlm.nih.gov
Cohort Studies in Medicine – www.bmj.com
Case-Control Studies – www.ncbi.nlm.nih.gov
Cross-sectional Studies in Epidemiology – www.cdc.gov
Randomized Controlled Trials (RCTs) – www.nice.org.uk
Double-Blind Study – www.ncbi.nlm.nih.gov
Triple-Blind Studies – www.theclinicaltrialsguru.com
In Vitro vs In Vivo Studies – www.ncbi.nlm.nih.gov