Public Health Flashcards
How to calculate positive predictive value?
True Positive / True Positive + False Positive
How to calculate negative predictive value
True negative / True negative + false negative
What is negative predictive value?
The proportion of people with a negative result who do not have the disease
What is positive predictive value?
The proportion of people with a positive test that actually have the disease
How to calculate sensitivity
True positive / True positive + False Negative
How to calculate specificity?
True negative / False positive + true negative
Give 3 strengths of cross-sectional studies
Quick/cheap
No long periods of follow up
Can be used for large data sets
Give 3 weaknesses of cross-sectional studies
Not suitable for rare diseases
Not suitable for diseases with a short duratiopn
Unable to measure incidence
Define sensitivity
The percentage of true positives. (The proportion of people who test positive among those who have the disease)
(sensitivity of 90% means 90% of people who have the disease will test positive)
Define specificity
Percentage of true negatives
(90% specificity = 90% of people who do not have the disease will test negative)
What are the 5 levels of Maslow’s Hierarchy of Needs?
Physiological needs.
Safety needs.
Love and belonging.
Esteem.
Self-actualisation.
Define Allostasis
The process of achieving stability, or homeostasis, through physiological or behavioural change.
Define Epidemiology
The study of the frequency, distribution and determinants of diseases and health-related states in populations in order to prevent and control disease
Define Incidence
The rate at which new diseases occur in a population in a certain time period
Define Prevalence
The proportion of a population found to have a disease at a point in time.
Define Person-Time
Describes the sum of the periods of time that each individual in the study has been at risk.
(in years/months or days) (i.e Person Years)
Used as the denominator in incidence rate calculations
Define relative risk. What does it tell us?
Describes the risk in one category relative to another.
I.e Ratio of risk of disease in the exposed vs the unexposed.
Tells us the strength of association between a risk factor and a disease.
What calculation can be used to work out relative risk?
Incidence in exposed ÷ Incidence in unexposed