Epidemiology is …
Figure 1.1 Time trends in lung cancer mortality rates in the USA (age-standardised to the 1970 US population) for white men (––) and women (___). (Drawn from: CDC Wonder Database…
Why? Linking exposure and disease
Looking for associations Ratio measures (relative risk) Rate ratios Risk ratios Prevalence ratios A note about relative risks Standardised incidence and mortality ratios Difference measures (attributable risk) Rate differences Risk…
Prevention: better than cure?
Disease prevention in public health The scope for preventive medicine Population versus individual risk Strategies for prevention The high-risk strategy The mass strategy The population attributable fraction as a guide…
Early detection: what benefits at what cost?
Why screen? The disease process Screening versus case-finding The requirements of a screening programme The disease The screening test Test quality: sensitivity and specificity Test performance in practice: positive and…
All that glitters is not gold: the problem of error
Sources of error in epidemiological studies Selection bias Some specific sources of selection bias Volunteers Low response rates Loss to follow-up Ascertainment or detection bias The healthy-worker effect Control of…
Muddied waters: the challenge of confounding
An example of confounding: is alcohol a risk factor for lung cancer? Characteristics of a confounder The effects of confounding How can we tell if an association is confounded? When…
Outbreaks, epidemics and clusters
Outbreaks, epidemics and clusters Epidemiology of infectious diseases A causal model The infectious agent The host Transmission The environment Non-infectious clusters and outbreaks Outbreak management and investigation Management of outbreaks…
Who sank the boat? Association and causation
What do we mean by a cause? Some definitions Association versus causation Evaluating causation Temporality Strength of association Consistency Dose–response relationships Biological plausibility Specificity Pulling it all together An example:…
Surveillance: collecting health-related data for epidemiological intelligence and public health action
The scope of surveillance Why conduct surveillance? Surveillance essentials Defining a case for surveillance purposes Collection of surveillance data Analysis of surveillance data Evaluation of surveillance systems Types of surveillance…
Epidemiology and the public’s health
From: www.Cartoonstock.com Challenges So what have we learned from this? The totality of evidence indicates that beta-carotene is a good marker of (and part of) a beneficial diet, but is…
