The web of causation model differs from the epidemiologic triad in that it emphasizes which aspect of disease etiology?

Explanation

## Epidemiologic Triad vs. Web of Causation ### Historical Evolution of Causal Models **Key Point:** The web of causation model evolved to address the limitations of the simple epidemiologic triad, recognizing that most modern diseases result from multiple, interacting causes rather than a single agent. ### Comparison of Models | Feature | Epidemiologic Triad | Web of Causation | |---------|-------------------|------------------| | **Causation** | Single agent (infectious focus) | Multiple interacting factors | | **Complexity** | Simple, linear | Complex, multifactorial | | **Best for** | Infectious diseases | Chronic diseases (CVD, cancer, diabetes) | | **Pathways** | One main pathway | Multiple pathways converging to disease | | **Interactions** | Agent-host-environment | Genetic, behavioral, environmental, social | ### Web of Causation Concept The web of causation recognizes that: 1. **Multiple causes are necessary** — No single factor is sufficient; disease results from the convergence of many factors 2. **Factors interact** — Smoking + asbestos exposure + genetic susceptibility → lung cancer 3. **Non-linear relationships** — Causes may be direct, indirect, or conditional 4. **Temporal sequence matters** — Causes must precede the disease **Example: Coronary Heart Disease Web** - Genetic predisposition - Hypertension - Hyperlipidemia - Smoking - Sedentary lifestyle - Stress - Obesity All these factors interact to increase risk; none alone is necessary or sufficient. **High-Yield:** The web of causation is the modern framework for understanding chronic non-communicable diseases and is heavily tested in epidemiology. **Mnemonic: MINCE** — **M**ultiple factors, **I**nteracting, **N**on-linear, **C**onvergent, **E**volutionary (over time) [cite:Park 26e Ch 2]