Unit 4

Question 1

Morbidity

Answer 1

refers to the disease state and often considers the burden of disease, such as sickness and impairment

Question 2

Mortality

Answer 2

refers to feath

Question 3

Prevalence

Answer 3

the number of existing cases of disease, can be point prevalence or as a peroid prevalence

simply a proportion not a measure of risk becuase it doesn’t take into account when the disease occured

Question 4

INcidence

Answer 4

a dynamic measure of disease or outcome occurrence over time. reuiqres at least two obersvations of the same individual, the first to establish who is at risk, for the disease and the second t confirm new cases of the disease,

prevalence= incidence x duration

prevalence will be greater then incidence for a chornic disease, for a short term illness, prevalence will be lower tan incidence

Question 5

incidnece risk

Answer 5

the proportion of unaffected individuals, who on average, develop the disease over a specific period

IR= # of new cases in a speficied time period / intial number at risk - 1/2 the withdrawls

Question 6

incidence rate (exact denominaotr

Answer 6

true rate, the speed which new cases os disease occur. the denominator is the sum of the units of time each indiidual was at risk.

at risk means an individual is disease free and has the potnetial to become a case

individual follow up data, exact denominator

IR=# of cases in a populaion in a given time period/ net time individuals in population are at risk during t

Question 7

incidence rate (approximate denominator)

Answer 7

averge the number at risk ffrom the start to the end of follow up periof and multiple by internal time conpment

both measure 2 things, the number of new cases among thoe at risk in a population and the number of new cases within a specific time period

Question 8

case fatality rate

Answer 8

measure of a particular disease

=# who die/# who have it

Question 9

attack rate

Answer 9

often used in outbreaks, food or water bourne

=# who get sick from exposure/# who have exposure

Question 10

relative risk

Answer 10

=risk of disease in exposure group/ risk of diseas ein nonexposure group

cannot be used in case control studies

Question 11

odd ratio

Answer 11

= odds of disease in exposure group/ odds of disease in non-exposed group

can be applied to case control studyes

RR and OR, for rare disease if prevalence is

Question 12

incidence rate ratio

Answer 12

=incidence rate of outcome in exposure group/incidence rate of outcome in non-exposure group

Question 13

risk rate

Answer 13

risk difference, subract the backgroud level of risk

RD= risk/rate in exposed - risk/rate in non-exposed

this is not a ratio,, therefore the null value is 0

if RD>0 then poostiviely assocated, RD

Question 14

attributable proportion exposed

Answer 14

the proportion of risk of the outcome in the exposed gourp that is attributable to that specific exposed

Ape= risk/rate exposed - risk/rate of non-exposed/ risk/rate in exposed

Question 15

population attributable risk/rate

Answer 15

expresses the amount of outcome in the entire population that is due to the exposure, subtracts the background risk

PAR=prevalence/rate of outcome in population - prevalence/rate of outcome in non-exposed

analgous to risk rate but for the whole population

Question 16

population attributable fraction

Answer 16

proprotion of the outcome in the entire populaion that is due to the exposure

PAF= prevalence of the outcome in population - prevalence in non-epxosed / prevalence of outcome in population