Introduction to Epidemiology

Epidemiology underpins evidence-based public health, using structured methods to investigate disease patterns, risk factors, and health outcomes in populations. It informs interventions and guides policy-making.

Nutritional Diseases

Environmental Diseases

Types of Epidemiological Studies

Observational designs (descriptive, analytical) provide information without intervention. Case-control, cohort, and cross-sectional studies offer different strengths and limitations.

Study Type	Strengths	Limitations	Best Use
Case-Control	Efficient for rare diseases	Recall bias	Disease causation
Cohort	Clear temporal sequence	Time-consuming	Risk factor identification
Cross-sectional	Quick, inexpensive	No causality	Prevalence estimation

Study Design Elements

Selecting appropriate populations, sample sizes, and data collection methods is essential. Surveys, medical records, biomarkers, and interviews provide data, while standardisation ensures quality.

Analysis Techniques

Descriptive statistics summarise data, inferential methods test hypotheses, and regression models evaluate associations. Risk measures (relative risk, odds ratio) quantify the strength of links between exposures and outcomes.