Epidemiology Flashcards
Epidemiologic Triad
Agent»_space;Host»_space;Environment (sometimes vector in middle)
Host factors
Degree to which individuals adapt to stressors produced by the agent (genotype, nutrition, immune system, behavior, BMI)
Agents of disease
Biologic (virus, bacteria, etc), chemical, physical, social
Environment
Probability and circumstances of exposure of host to agent
Vectors
Insects, arthropods, animals (must have specific relationship with agent, host, and environment)
Endemic
Constant presence of disease in specific geographic area
Epidemic
Outbreak of a disease affecting many people in a specific region
Pandemic
Worldwide epidemic
Iatrogenic
Symptom or disease caused by medical treatment
Natural history of disease
Normal»Preclinical phase (after biologic onset of disease)»Clinical phase (symptoms first appear»disease diagnosed»therapy given)
Primary prevention
Preventing the initial development of disease (immunization, smoking cessation)
Secondary prevention
Early detection in the preclinical phase to slow/prevent progression or reduce complications (screening for cancer or prediabetes)
Tertiary prevention
Reducing impact of disease or comorbidities (diabetic foot checks, stroke rehab)
Prevalence
Proportion of population with disease (# of existing cases at a given time point/total population at risk)
Incidence
proportion of population developing new cases of disease (# of newly diagnosed cases during a time period/total population at risk)
Annual mortality rate (all cause)
(# of deaths in 1 year/# of people in population at midyear)*1000
Case-fatality rate
Percentage of deaths among patients with the disease (# of individuals dying during a specific time frame after diagnosis/# of individuals with the disease)*100
Epidemiology studies can be either…or….
Observational; experimental
Observational studies
Descriptive, ecological, cross-sectional, case-control, cohort
Experimental studies
Randomized clinical trials (RCTs)
Hierarchy of evidence
Lab research»case series/reports/case-control studies»cohort studies»RCT»systematic review»meta-analysis
