Disease
distribution: how are cases of the condition of interest spread across a population
differently by gender, age, geographic location, socio-economic status, other features?
Disease determinants: what risk factors or antecedent
events are associated with the appearance of a disease or condition?
Disease frequency: how many cases of the condition occur
over a given time period?
- Expected level - baseline level of observed occurrence of a particular disease
- Endemic - persistent occurrence at a low to moderate level, sometimes referred to as a
high background rate
- Sporadic - irregular pattern with occasional cases occurring at irregular levels
- Epidemic - occurrence of a disease within an area exceeds expected level for a given
time. Also called an outbreak.
- Note that these mean basically the same thing, but public perspective is that epidemic
is much more serious than an outbreak.
- Pandemic - epidemic that has spread over several countries or continents, affecting
large numbers of people
