Public Health Flashcards
Define Incidence and Prevalence
Incidence - New cases in population
Prevalance - population number affected at time
Define lead time bias
Pt identified earlier appears to live longer
Define length time bias
Diseases slow growing more likely to be identified, therefore giving impression that screening results in higher survival
selection bias
error in selection or allocaiton. Proper randomisation not achieved
Information bias - measurement, observer, recall, and reporting?
Measurement - Different equipment used
Observer - researcher subconsciously records differently
Recall - Events not remembered correctly
Reporting - Suppression of info, embrassment
Publication bias
Negative results less likely to be published
Confounding factor
Association can be explained by unmeasured variable
Reverse Causality
Outcome causes exposure
Give WHO screening criteria for the condition, method, treatment, and screening programme
Condition must be - understood, identifiable latent phase, important health issue
Method must be - suitable to population
Tx - effective and accepted
Programme must be - Cost effective, benefit must outweigh harm (false postitive and negatives)
sensitivity vs specificity
Sensitivity - Positive correctly identified
Specificity - negative correctly identified
PPV vs NPV?
PPV - Porportion with positive result that have disease
NPV - proportion with negative result that dont have disease
What is case control study? pros and cons
case control - cases with conditions vs people without
Pros - Good for rare disease. Quick and cheap
Cons - Prone to selection bias
What is cohort study? Pros and cons
Cohort - People followed over time and exposure and disease recorded
Pros - Good for rare exposures. Decrease selection bias
Cons - Time consuming, needs large sample size
What is cross sectional study? pros and cons
Cross sectional study - one or more variables studied at one point in time
Pros - Quick, cheap, large sample size
Cons - Risks of recall bias, reverse causality, non-respondance
Define primary, secondary, tertiary prevention
Primary - remove risk factors of disaease
Secondary - prevent progression in early stages
Tertiary - Minimise disability in established disease
Bradford Hill Criteria?
So Sick And Tired Cant Do Revision S - Strength of association S - Specificity A - Analogy, similarity to other cause effect relaionships T - Temporality. Exposure before outcome C - Coherence and Consistency. Logical. D - Dose response R - Reversibility
Define absolute and relative risk
Absolute - overall likelihood of ocurrence
Relative - incidence in exposed / incidence in unexposed
Define economic efficiency
Resources allocated to maximise benefit
Define incremental and marginal cost
Incremental - Difference in cost + QALYS between different treatments
Marginal - Cost incurred in producing 1 more unit
Health behaviour and illness behaviour
health behaviour - aimed at preventing disease
Illness behaviour - aimed at seeking remedy
Theory of planned behaviour
Prediction of behaviour can be attained by intention which itself is determined by attitude, subjective norm (what others think), and behavioural control (I cant quit)
Transtheoretical (stages of change) model
Pre-contemplation to contemplation to preparation to action to maintenance
Health inequality vs inequity
Inequality - differences in healthcare due to individuality
Inequity - Differences due to injustices
