Vertically in columns build mathematical structure

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Yes a b (a+b)
No c d (c+d)
(A+C) (b+d) N
Measurements of Disease (video)
 Ratio
o One measure divided by another, no implicit relationship
 Proportion—those present in numerator are present in denominator
 Rate—disease occurring in population over specific period of time
 Risk
o Accumulated effect of some rate of disease operating over certain timeframe
o Probability that some event will occur, time frame is key component
 Risk ratio
o Risk is occurring in certain group against those that don’t have exposure
o Risk of lung cancer (smokers vs non smokers)
 Incidence
o New cases of disease during time you are measuring
o Incidence: # new cases/population at risk over timeframe
o exact onset of disease uncertain so need to define onset, a ‘case’ definition
o good for evaluating risk/probability, excluded people who have already had
disease
o Inc Exposed= a/(a+b)
o Inc Unexposed= c/(c+d)
 cumulative incidence
o number of new cases during a period of time / number of disease free individuals
at beginning of observation period
o # new cases/ # disease free @ beginning of observation period
 prevalence
o what exists at time you are measuring
o prevalence: total # cases/ total population at risk
o P= (a+c)/N
 point prevalence
o # cases at the instant in time you count
 relative risk
o risk of one group with exposure compared to risk of another group not exposed
o IR exposed / IR unexposed
o RR=(A / (a+b))/ (c/(c+d))
 Attributable risk
o Amount of risk due to factor, excess risk
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1/30/2018
Lecture 7
 Culture
o Culture is the lens through which we see/perceive the world
 “Explanatory Model”
o Explanatory model of health and illness
 What people in a given culture believe about the nature, cause,
prevention, and response to a health-related event
o Reality is socially and culturally constructed from experiences interpreted in a
particular environment/context
o Explanatory models demonstrate the role of culture in shaping a person’s
interpretation of the meaning of illness and disease
o Types of explanatory models
 Focus on balance in:
 Energy (Shakra)
 Social Relationships
 Hot/cold
 Focus on relationships that are spiritual between:
 Humans (i.e. susto)
 Humans and non-humans/supernatural
 Focus on Environmental Forces
 Natural Elements
 Natural Forces
 Germs
 The biomedical model assumes illness is physical and that illness
operated according to the causal principles of the physical world
 A Western Explanatory Model
o The “Plumbing model” or metaphor of the body
 Body is a series of cavities/chambers (chest, stomach) connected by pipes
or tubes (windpipe, intestines, blood vessels)
 To maintain health, all pipes must be clear to allow free flow (or air,
blood, food, urine, feces) between cavities or to the outside
 Disease is the result of a blockage
 Laxatives or enemas relieve constipation; we clear/flush out the “system”
by drinking a lot of water
 When under stress we “blow off steam”
 Arteries are “clogged” and need to be cleared
 Ear, nose are “plugged”
 Example: Public Health
o