Retrospective analysis involves looking back at past data or events to analyze and evaluate their outcomes or impact. This research method involves studying historical data, records, or events to identify patterns, trends, or lessons learned that can inform current or future decisions or actions. Retrospective analysis is often used in various fields such as healthcare, social sciences, business, and policy-making to understand the reasons behind certain outcomes, assess the effectiveness of interventions or policies, and identify areas for improvement. It provides valuable insights into the past events and helps in making informed decisions based on past experiences.