Clinical epidemiology studies how diseases occur and spread within patient populations and how to apply that knowledge to improve clinical decision-making. It provides the methodological backbone for interpreting studies, assessing diagnostic tests, and evaluating treatment effects. This book presents study designs, bias and confounding, measures of association, and basics of causal inference in a clinically oriented way. Practical chapters show how to read medical literature, appraise randomized trials, and apply evidence to individual patient care. Worked examples, diagnostic accuracy tables, and simplified statistics help clinicians move from numbers to practice. Ideal for clinicians, residents, and public-health students seeking to make evidence-based choices.