Abstract The epidemiologist Bradford Hill famously argued that in epidemiology, specificity of association (roughly, the fact an environmental or behavioral risk factor is associated with just one at most a few medical outcomes) strong evidence causation. Prominent epidemiologists have dismissed Hill’s claim on ground it relies dubious `one-cause effect’ model disease paper examines this method...

results the highest prevalent genotype was genotype 4a, which was found in 57 patients (92%) followed by 2 isolates (3%) with genotype 4o, 2 strains (3%) with genotype 1g and one isolate (2%) with genotype 4n. conclusions this molecular epidemiology study revealed high prevalence of hcv genotype 4, subtype 4a among egyptian patients residing in sharkia governorate, egypt. patients and methods t...

1. What Is Epidemiology? 2. Purposes of Epidemiology 3. Defining and Measuring Health and Disease 3.1. Disease Nomenclature and Classification 3.2. Counting Disease 3.3. Severity of Disease 3.3.1. Mortality 3.3.2. Morbidity 3.3.3. Composite Measures Combining Morbidity and Mortality 4. Descriptive Epidemiology 4.1 Infectious Disease Triad 4.2 Descriptive Epidemiology Triad 4.3. Health Indicator...