Module 2 Flashcards
What are three general categories of rates?
Crude
Specific
Adjusted
Definition of crude rates
Summary rates based on the actual number of events in a population over a given time period.
Crude birth rate formula
Crude birth rate = (number of live births within a given period/Population size at the middle of that period) x 1,000 population
Purpose of crude birth rate
Useful measure of population growth
An index for comparison of developed and developing countries.
General fertility rate definition
Consists of the number of live births reported in an area during a given time interval, divided by the number of women aged 15-44 years in that area.
Total fertility rate definition
The average number of children that would be born per woman if all women lived to the end of their childbearing years and bore children according to a given set of age-specific fertility rates.
Fetal mortality definition
Spontaneous intrauterine death at any time during pregnancy
Fetal death rate formula
(Number of fetal deaths after 20 weeks’ gestation or more/number of live births + number of fetal deaths after 20 weeks or more ) x 1,000
Fetal death ratio formula
(Number of fetal deaths after 20 week’s gestation or more/number of live births) x 1,000 (during a year)
Infant mortality rate formula
(Number of infant deaths among infants aged 0-365 days during the year/number of live births during the year) x 1,000 live births
Neonatal mortality rate formula
(Number of infant deaths under 28 days of age/number of live births) x 1,000 lived births (during a year)
Postneonatal mortality rate formula
(Number of infant deaths from 28-365 days after birth/number of live births - neonatal deaths) x 1,000 live births
What is considered the perinatal period?
Late fetal deaths (stillbirths) plus infant deaths within 7 days of birth
Late fetal death rate formula
(Number of fetal deaths after 28 weeks’ gestation or more/number of live births + number of fetal deaths after 28 weeks’ or more gestation) x 1,000
Perinatal mortality rate formula
(Number of late fetal deaths + infant deaths within 7 days of birth/number of live births + number of late fetal deaths) x 1,000 live births and fetal deaths
Perinatal mortality ratio formula
(Number of late fetal deaths + infant deaths within 7 days of birth/number of live births) x 1,000 live births
What are factors that affect maternal mortality?
Maternal age
SES
Nutritional status
Healthcare access
Maternal mortality rate formula
(Number of deaths assigned to causes related to childbirth/number of live births) x 1,000 live births (during a year)
Specific rates definition
A type of rate based on a particular subgroup of population defined, for example, in terms of race, age, or sex, or they may refer to the entire population but be specific for some single cause of death or illness.
Cause-specific rate definition
A rate that specifies events, such as deaths according to their cause.
Cause specific rate formula
Cause specific rate = (mortality for frequency of a given dz/population size at midpoint of time period) x 100,000
What is a disadvantage of specific rates?
The difficulty of visualizing the big picture of these situations.
Proportional mortality rate (PMR) formula
PMR= (Mortality due to a specific cause during a time period/mortality due to all causes during the same period) x 100
What does PMR not measure?
The risk of dying of a particular cause
Definition of adjusted rates
Summary measures of the rate of morbidity or mortality in a population in which statistical procedures have been applied to remove the effect of differences in composition of the various populations.
What are two methods for adjusting rates?
Direct and indirect
Direct method definition
A rate adjustment that applies specific rates for a group to a standard population.
When would a direct method be used?
If age-specific death rates in a population to be standardized are known and a suitable standard population is available.
What are the requirements for direct adjustment?
The application of the observed rates of dz in a pop to some standard pop to derive an expected # (rate) of mortality.
When is the indirect method used?
If age-specific death rates of the population for standardization are unknown or unstable
Standard mortality ratio formula
SMR= observed deaths/expected deaths
Case fatality rate formula
CFR (%) = (# of deaths due to disease X/# of cases of disease X) x 100 during a time period.
What are ways of measuring morbidity?
Prevalence
Incidence
Quality of life measures (disability adjusted life years)
What questions do cause-specific mortality answer?
How likely is death from this cause among the whole population?
What is the risk of death from this cause for the whole population?
What questions do case-fatality rate answer?
Given that one acquires the disease, how likely is it to kill you?
How lethal is this disease, once you get it?
What influences the cause-specific mortality rate?
Case-fatality
Incidence of the dz
Where do the numerators from mortality statistics come from?
Death certificates
What information do death certificates contain?
DOB of date of death
Stated age
Place of birth
Place of residence
Education
Occupation
Sex
Race/ethnicity
Marital status
Up to four causes of death
ICD-10 code for cause of death
Order of causes of death on a death certificate
Immediate cause of death
Up to three contributing causes
The underlying cause (any disease or injury which initiated the set of events resulting in the death)
What influences the birth rate?
The proportion of the population that is of childbearing age
The average number of children that each woman has
Causes of neonatal mortality in developed countries
Congenital malformations
Prematurity
Low birth weight
Maternal complications of pregnancy
Causes of neonatal mortality in developing countries
Low birth weight
Trauma/asphyxia
Tetanus
Causes of post-neonatal mortality in developed countries
SIDS
Accidents
Congenital malformations
Causes of post-neonatal mortality in developing countries
Pneumonia and other infectious diseases
Malnutrition
Accidents
Trends in developing vs developed countries in neonatal vs post-neonatal
Developed countries: mostly neonatal
Developing countries: mostly post-neonatal
Leading causes of maternal mortality
Hemorrhages
Lack of access to healthcare
Infections
Eclampsia
Poor sanitation
Unsafe abortions
Lack of contraceptives
Child marriage
Women treated as inferiors
Limitation of category-specific rates
May be confusing when stratifying on multiple variables such as age, race, gender
Tables become incomprehensible
Use of adjusted rates preferred in these situations
