Iranian Journal of Surgery 1735-4099 34 Spring 2026 05 22 Epidemiological Metrics: Risk, Absolute Risk, Relative Risk, and Risk Reduction خطر (Risk)، خطر مطلق (Absolute Risk)، خطر نسبی (Relative Risk) و کاهش خطر (Risk Reduction) 98 100 736429 EN Seyed Abbas Mirmalek Assistant Professor of General Surgery, Islamic Azad University of Medical Sciences, Tehran Branch Journal Article <strong>Risk is defined as the probability of a specific health outcome occurring within a specified population over a defined period. Absolute risk quantifies the incidence of an outcome within a group, while relative risk provides a comparative measure between two distinct populations, such as exposed and unexposed groups. These metrics are fundamental in clinical research for assessing disease prevalence and determining the efficacy of interventions.</strong> <strong><span lang="AR-SA">تعداد موارد مبتلا به یک بیماری دریک جامعه آماری را خطر مطلق می‌گویند. خطر نسبی وقتی است که بروز بیماری در دو گروه مقایسه می‌شود.</span></strong> https://ijs.ir/article_736429_15dc3404fa6ff1938290494c789d9a4c.pdf