Module 1 lesson 3 Flashcards
prevalence
proportion that measures the burden of disease in a population. NOT a reliable measure of risk
Point prevalence
number of existing cases at a point in time divided by the size of the population.
Period prevalence
calculated as existing cases at start of time period plus new cases over a period of time all divided by the size of the population of interest.
=point prev +cummulative prev
Death rate
the number of deaths due to a particular condition in a specified population divided by total time at risk for specified population.
Measures of association
difference measure, ratio measure
difference measure
est the absolute effect of a factor on risk or magnitude for health outcome
Ex: Incidence rate difference
Purpose of epidemiology
describe disease occurance in human populations
a scientific search for harmful and beneficial risk factors
need to measure potential risk factors and health outcomes
measures of disease occurrence
based on discrete events, but measure may be treated as a numerical variable or categorical variable
For rate: # of events occurring in population/time over which the event takes place
For proportion: # of events occuring in population/size of population
incidence proportion
incidence rate
death rate
prevalence
measures of association
difference measures (risk difference or attributable risk ratio measures (incidence rate ration and odds ratio)
Stratification measures
crude measures
specific measures
Incidence proportion
estimate for risk in population
calculated as number of people developing the health outcome divided by size of population
time over which measurement is made must be included in description
assumes fixed population (everyone has same risk)
incidence rate
estimate for change in risk over time in a population at risk
calculated as a number of people developing the health outcome divided by total time at risk for the population
used for dynamic populations because it takes into account individual time at risk (person time)
At the initial examination in the framingham study, CHD was found in 10/1000 men age 40-44 yr and in 10/1000 women age 40-44. based only on the information given here, which of the following conclusion can be made?
- women have the sme risk of developing CHD as men
- age specific incindence rate was measured at the initial examination
- none of the choices
- the prevalence of CHD for women is the same as the prevalence of CHD for men
- The incidence proportion of CHD in women was greater than for men
- the prevalence of CHD for women is the same as the prevelence for CHD for men
In a work place with 300 empployees, the following occurrences of new cases of respiratory distress was observed over 3 months: end of mo 1: 10 cases; end of mo 2: 15 cases; end of month 3: 25 cases. Assumes for the calculation of the incidence rate over the 3 month time period that all cases occurd on last day of month. Which of the following values for peron-month should be used in denominator?
- 865 person mon
- 675
- 900
- 300
NOT 300
900
We want to compare the risk of deveoping diabetes btw brookings and Sioux Falls in 2010. which measure of association would be best for this?
- rate ratio
- incidence rate
- prevalence ratio
- proportionate mortality ratio
- a spot mat tat records all existing cases of dm in 2010
NOT incidence rate
rate ratio
Which of the following best describes the risk difference?
- The risk for the exposed population minus the risk for the comparison population
- The risk difference divided by the risk for the exposed population
- The risk for the exposed population divided by the risk for the comparison population
- The relative effect divided by the risk for the comparison population
- The risk for the exposed popuation minus the risk for the comparison population
A newspaper claims yoga decreases risk of hair loss by 30%. what is the rate ratio that would correspond to this decrease?
- none of these
- 3
- 0.3
- 1.3
- 0.7
NOT 1.3
0.7
Which of the following choices is the numerator for the annual prevalence of diabetes for sd in 2010
- number of people who have dm on 1.1.10 and number of new cases in SD in year 2010
- total number of new cases in sd in yr 2010
- total number of people with dm in sd at start of yr 2010
- none of these
- number of people who have dm on 1.1.10 and number of deaths due to dm in sd in yr 2010
NOT “none of these”
1
which of measures listed below would be best to eval the risk of adhd varies in sd school districts
adhd incidence rates
The numerator for annual death rate from heart diseasse in us wome would include
- none
- us women living with hd t/o yr
- people with hd on first day of yr
- deaths due to hd among us women during the yr
- new cases of hd among us women occur during yr
NOT us women livin with hd t/o year
4
CDC aids
incidence rate increased bc numerator increased
rate ratio of 20 can have interpretation
exposed population has a much higher incidence rate than reference population
which of the following is the highest value
100000 per 100000
In a work place with 300 empployees, the following occurrences of new cases of respiratory distress was observed over 3 months: end of mo 1: 10 cases; end of mo 2: 15 cases; end of month 3: 25 cases. Assumes for the calculation of the incidence rate over the 3 month time period that all cases occurd on last day of month. Which of the following is the approximate incidence rate for the 3 month time period? 60/1000 90/1000 35/1000 100/1000
NOT 35/1000
60/1000
IR is preferred over IP for calculating risk in populations________
whose membership changes over time
