Week 2 - Non-communicable (Chronic) diseases
● Epidemiologists tend to specialize in non-communicable (chronic) diseases or
communicable (infectious) diseases
What is a chronic disease?
● Lasts 3 months or more and generally cannot be prevented by vaccines or cured by
medication nor do they just disappear
● Examples (PHAC)
○ Cancer
○ Heart disease → hypertension, stroke
○ Respiratory → asthma, COPD, sleep apnea
○ Diabetes
○ Mental illness
○ Neurological conditions → paralysis, cognitive impairment
○ Musculoskeletal → arthritis, osteoporosis
Nature of Chronic Diseases
● Multiple causation of chronic diseases
○ Necessary cause → factor must be present for disease to develop
○ Sufficient cause → in presence of factor disease always develops
● Potential risk factors divided into 2 categories
○ Host → factors intrinsic to the individual
○ Environmental → factors external to individual
Models of Causation
● Epidemiologists tend to specialize in non-communicable (chronic) diseases or
communicable (infectious) diseases
What is a chronic disease?
● Lasts 3 months or more and generally cannot be prevented by vaccines or cured by
medication nor do they just disappear
● Examples (PHAC)
○ Cancer
○ Heart disease → hypertension, stroke
○ Respiratory → asthma, COPD, sleep apnea
○ Diabetes
○ Mental illness
○ Neurological conditions → paralysis, cognitive impairment
○ Musculoskeletal → arthritis, osteoporosis
Nature of Chronic Diseases
● Multiple causation of chronic diseases
○ Necessary cause → factor must be present for disease to develop
○ Sufficient cause → in presence of factor disease always develops
● Potential risk factors divided into 2 categories
○ Host → factors intrinsic to the individual
○ Environmental → factors external to individual
Models of Causation
