A **randomized [[double-blind]] [[controlled trial]] (RCT)** is a gold-standard study design used to evaluate the efficacy and safety of an intervention. It minimizes bias and increases the reliability of the results. Below are the key elements:

### **1. Randomization**
- Participants are **randomly assigned** to different groups (e.g., treatment vs. control) to reduce selection bias.
- Ensures that **known and unknown confounders** are evenly distributed between groups.

### **2. Double-Blind Design**
- **Neither the participants nor the researchers** know who is receiving the treatment or placebo.
- Prevents **observer bias** (researchers influencing results) and **placebo effect** (participants’ expectations influencing outcomes).

### **3. Control Group**
- A **comparison group** that receives a placebo, standard treatment, or no treatment.
- Helps determine if the intervention truly has an effect **beyond natural recovery or existing treatments**.

### **4. Outcome Measures**
- Predefined **primary and secondary outcomes** are measured to assess the effectiveness and safety of the intervention.
- Can include **biomarkers, clinical assessments, imaging results, or patient-reported outcomes**.

### **Advantages of RCTs**
✔ **Highest level of evidence** in clinical research.  
✔ **Reduces bias**, increasing reliability of results.  
✔ Allows for **causal inferences** between intervention and outcomes.  

### **Limitations of RCTs**
❌ **Expensive and time-consuming**.  
❌ May have **ethical concerns** (e.g., withholding treatment from a control group).  
❌ **Generalizability issues** if strict inclusion/exclusion criteria are used.