Community Health Final exam

Epidemiology

study of occurrences & distribution of health-related states or events in specified population, including the study of the determinants influencing such states & the application of this knowledge to control the health problem

crude mortality rate calculation

(number of deaths from a certain disease during a specified time divided by number of cases of that disease occurring w/i the same specified time period) multiplied by 100,000

crude mortality rate

compare the number of deaths from a specified cause w/i the entire population (ex. deaths from motor vehicle accidents)

specific mortality rate calculation

(total deaths from a specified cause during a specified time period in a population (subgroup) divided by average number of population (subgroup) w/i that specified time period) multiplied by 100,000

specific mortality rates

compare the number of deaths from a specific cause in a particular subgroup w/ that whole subgroup (ex., teenage male deaths from motor vehicle accidents)

prevalence rate calculation

number of people w/ given disease in given population at 1 point in time divided by total population in given population at same point in time

incidence rate calculation

number of NEW cases of given disease in a population during a specified time period divided by average total population w/i the same specified time period

temporal relationship

a person does not get the disease until after exposure to the cause (ex. H. pylori is clearly linked to chronic gastritis. about 11% of chronic pts will go on to develop duodenal ulcers over a 10-year period)

strength of association

exposure to a specific stressor or cause is most likely to bring on the disease b/c they are strongly associated (ex. H. pylori is found in at least 90% of pts w/ duodenal ulcer) (how strong is the link)

dose-response

persons who are most exposed to the contaminated food are the most ill (ex. density of H. pylori per square millimeter of gastric mucosa is higher in pts w/ duodenal ulcers)

specificity

the cause is linked to a specific disease (ex. prevalence of H. pylori in pts w/ duodenal ulcers in 90-100%)

consistency

everyone who eats contaminated food gets the illness - if other food in another time & place is contaminated w/ the same bacteria, the same illness occurs (ex. duodenal ulcer is caused by H. pylori. whenever a person is exposed to H. pylori, they will get duodenal ulcer & not another disease)

biological plausibility

findings are consistent w/ the biological/medical knowledge that is known (ex. although originally it was difficult go envision a bacterium that infects the stomach antrum causing ulcers in the duodenum, it is now recognized that H. pylori has binding sites in antral cells & can follow these cells into the duodenum)

experimental replication

several studies done by different scientists in different places produce the same or similar results (ex. many of the observations regarding H. pylori have been replicated repeatedly)

coherence

how well assumptions about the causal relationship fit into existing theory (ex. smoking causes lung cancer - this relationship is coherent w/ existing biological & epidemiological theories. research has demonstrated that carcinogens in tobacco smoke cause mutations in lung cells, which aligns w/ existing models of cancer development)

analogy

association between analogous exposures & outcomes indicate a similar causal mechanism & many strengthen a causal arguments (ex. if thalidomide exposure during pregnancy causes birth defects, then another drug w/ a similar chemical structure might also pose a risk during pregnancy)