==== Clinical trial ====

A **clinical trial** is a structured, prospective research study conducted on human participants to evaluate the **safety**, **efficacy**, or **optimal use** of a medical intervention—such as a drug, device, surgical technique, or diagnostic method.

Clinical trials are typically conducted in **phases**:

  * **Phase I** – Assesses safety and dosage in a small group of healthy volunteers or patients.
  * **Phase II** – Evaluates preliminary efficacy and side effects in a larger patient group.
  * **Phase III** – Confirms efficacy and monitors adverse reactions in large populations across multiple centers.
  * **Phase IV** – Post-marketing surveillance to gather long-term safety and effectiveness data.

In [[neurosurgery]], clinical trials are crucial for validating innovations like new [[implantable devices]], [[surgical techniques]], or technologies such as [[3D virtual reality]] and [[robotic-assisted surgery]].

A properly designed clinical trial includes:

  * Defined inclusion and exclusion criteria  
  * Randomization and control groups  
  * Blinding (where possible)  
  * Statistically powered sample size  
  * Pre-registered outcomes and ethical approval

Clinical trials are a cornerstone of [[robust evidence]] and are essential for integrating new interventions into standard practice.