Disease Frequency II

Question 1

What is crude mortality rate?

Answer 1

Mortality rate from all causes is known as the crude or all-cause mortality rate

Question 2

What is the formula for CMR?

Answer 2

total # of deaths from all causes during a given time period/#of persons in population at midpoint of time period *100,000

Question 3

Note, i am not sure what this means

Answer 3

Calculated among all individuals in a population thought to be at risk, not among everyone in the population

Question 4

What is infant mortality rate? What does a high rate indicate?

Answer 4

-Number of infant deaths among infants aged 0-365 days during the year/number of live births during the year *1,000 live
births
-unmet health needs and poor environmental conditions

Question 5

Formula for cause specific mortality rate

Answer 5

• mortality (or frequency of a given disease)/population size at midpoint of time period *100,000
• Specific rates refer to a particular subgroup of the population defined in terms of race, age, sex, or single cause of death or illness.

Question 6

What is case fatality rate? What does a high rate indicate?

Answer 6

-How many of those infected or inflicted with disease will die (percent)?
-number of cases of the disease during the same time period (population at risk of dying from the disease)*100
-A high rate observed among vulnerable groups living in high risk areas. They reflect limited access to proper health care for the most vulnerable people and insufficiencies in health-care systems, including limited capacity of the surveillance system to trigger a timely response.”
CDC
-Might tell you if there is a vulnerable population, determines how severe the public health response will be, and how intense the public health preventative measures will have to be

Question 7

Proportionate mortality (not a rate)

Answer 7

• What proportion of the deaths in a population during a specific time were caused by a specific disease
• number of deaths from disease X during a specific time period/total deaths during the same time period

Question 8

Have caution when using crude rates!

Answer 8

• Observed difference may be due to systematic factors (ex: sex or age distributions) within the population rather than true variation in rates
• address by using specific or adjusted rates

Question 9

What is age-specific rate?

Answer 9

-The number of cases per age group of population
(during a specified time period)/number of persons who are aged 5-15 years during time period
-Adult diseases is generally per 100,000
infant diseases is generally per 1,000

Question 10

What is direct standardization

Answer 10

wanting to standardize one population with another so that your numbers can be directly comparable

Question 11

What are adjusted rates

Answer 11

EX: Age adjusted mortality rates, summary measures of the rate of morbidity and mortality in a population in which statistical procedures have been applied to remove the effect of differences in composition of various populations

Question 12

standardized mortality rate

Answer 12

-observed deaths/expected date*100
-If the observed and expected numbers are the same, the SMR would be 1.0, indicating that observed mortality is not unusual
An SMR of 2.0 means that the death rate in the study population is two times greater than expected

Question 13

What are the clear components of surveillance?

Answer 13

Case definition – operational definition to accurately and reliably identify and count the health problem
Scope – geographic area, population, time period
Clear objectives – how will data be collected, consolidated, analyzed

Question 14

What are the sources of data for surveillance?

Answer 14

Three sources: individuals, environment, healthcare providers / institutions
Information about disease course, size of population under surveillance (rates) and geography are helpful
Collected continuously, periodically, or defined period
Types
Primary - environmental monitoring, syndromic surveillance, notifications, registries (including vital statistics)
Secondary - medical records, school records, other administrative data, surveys

Question 15

Active vs passive surveillance in

Answer 15

Active: health department contacts healthcare providers or laboratories about conditions to identify cases
Advantage – useful when need to identify all cases
Disadvantage – requires more resources
Passive: health departments rely on healthcare provider or laboratories to report cases of disease
Advantage – efficient, requires limited resources
Disadvantage – incomplete due to underreporting

Question 16

What is sample?

Answer 16

who is in your study

Ex: a random selection of adolescents from the enrollment list

Question 17

what is sampling frame?

Answer 17

is there a list of population members?

EX: Enrollment list of adolescents in NYC schools

Question 18

what is the study population?

Answer 18

what part of the population can you get access to

Ex: Adolescents in schools in NYC

Question 19

What is the target populatino?

Answer 19

Who you want to generalize to

EX: All the adolescents in the U.S.