**Core Concept**
Medical audit is a systematic review of medical practices, procedures, and outcomes to assess the quality of care provided and to identify areas for improvement. It is a crucial tool in quality assurance and quality improvement in healthcare settings.

**Why the Correct Answer is Right**
Medical audit involves a thorough examination of medical records, patient outcomes, and treatment protocols to evaluate the effectiveness of care. It helps to identify variations in practice, assess the impact of interventions, and develop strategies to improve patient outcomes. Medical audit can be done at the individual, team, or institutional level, and it is essential for ensuring that healthcare providers adhere to established guidelines and standards of care.

**Why Each Wrong Option is Incorrect**
**Option A:** Medical audit is not typically done to determine the cost-effectiveness of a treatment, although cost analysis may be a component of the audit process.
**Option B:** Medical audit is not solely focused on patient satisfaction, although patient feedback is an important aspect of the audit process.
**Option C:** Medical audit is not a one-time event, but rather an ongoing process that involves regular review and evaluation of medical practices.

**Clinical Pearl / High-Yield Fact**
A key aspect of medical audit is to identify "near misses" or adverse events that did not result in harm to the patient, but could have done so. This information can be used to develop strategies to prevent similar events from occurring in the future.

**Correct Answer:** C. Medical audit is an ongoing process that involves regular review and evaluation of medical practices.