Morbidity And Mortality Flashcards
________ is the most important tool for measuring disease or death i.e. morbidity or mortality.
Rate
RATE
Useful observations can be interpreted when they are related to a _________ in terms of a rate.
denominator
RATE
Rate is used to measure events that are related to the population or subgroup of it, in which they occur, or special events that are related to the total events. The event may be death, birth, occurrence of disease, immunization coverage, admission to hospital etc.
Rate is usually expressed as _________ per _______________
so many events
standard population size
Rate = (a/a+b)K
Where,
a = _________________________
a + b = ________________
K is the _________. Some number such as 10, 100, 1000, 10000, 100000.
the frequency with which an event has occurred during some specified period of time
the number of persons exposed to the risk of the event during the same period of time
multiplier
A ratio is a ______ of the form
(c/d)k
where k is ________ as already defined and both c and d refer to the __________ of some event or item.
fraction
some base
frequency of occurrence
A ratio
In the case of a ratio, as opposed to a rate, the _________________.
numerator is not a component part of the denominator
We can speak, for example, of the ________ ratio or the ___________ ratio of a certain geographic area. The values of k most frequently used in ratios are _____ and ______
person–doctor
person–hospital- bed
1 and 100
INCIDENCE RATE
Incidence rate measures the _______ that _____________________________ during a specified period of time.
probability
healthy people will develop disease or health–related event
INCIDENCE RATE
It indicates the rate at which ________ occurs in a defined, __________ population.
new disease
previously disease–free
INCIDENCE RATE
IR = _______________________
____________________________________ xK
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Number of new cases of a disease over a period of time
Population at risk
INCIDENCE RATE
This rate which measures the degree to which new cases are occurring in the community is useful in helping determine the need for initiation of preventive measures. It is used for (acute or chronic?) diseases.
Acute
PREVALENCE RATE
The prevalence rate measures the _____________________ at a given time.
number of people in a population that have a disease
PREVALENCE RATE
There are two types of prevalence rate,
the _________ and the __________.
point prevalence
period prevalence
PREVALENCE RATE
Point prevalence measures the probability of people _______________, whereas period prevalence measures the number of people that _______________________.
having a disease at one particular point in time
have a disease within a given period of time
The prevalence rate of a disease in a particular locality includes the __________ and the ___________ before it is terminated either by ________ or ________ .
incidence rate
average duration
recovery or death
Prevalence rate can be altered when people with a disease _____________ or _______________ .
immigrate into or emigrate from a population
Prevalence rate
Among workers, for example, any serious illness is likely to lead to ___________________, and consequently the prevalence rate is (more or less?) than that predicted from the __________ and _______
absence from workplace
Less
incidence rate and duration
Prevalence does not depend on the number of people that have been ill in the past and the duration of their illness.
T/F
F
Prevalence depends on the number of people that have been ill in the past and the duration of their illness.
Prevalence = ________ X ________
Incidence
Average duration
For an acute epidemic disease like CHOLERA or EBOLA, the prevalence rate is (low or high?) because the ________________ as a result of ________________.
This is contrary to the situation in a chronic disease like DIABETES MELLITUS or TUBERCULOSIS, where the prevalence rate is (low or high?) as a result of the __________ of the illness.
Low ; duration of illness is short; either quick recovery or death
High; long duration
Prevalence rate: _______________ existing at a point in time
______________________________ x K
_____________ at that point in time
total no of cases, new or old
total population
DIFFERENCES BETWEEN INCIDENCE AND PREVALENCE
Numerator:
Denominator:
Focus:
Number of new cases of disease; Number of existing cases of disease
Population at risk; total population
Whether the event is a new case, Time of onset of the disease is definite; Presence or absence of a disease
Time period is arbitrary It’s a “snapshot” in time
DIFFERENCES BETWEEN INCIDENCE AND PREVALENCE
USES!!!
Expresses the risk of becoming ill
Estimates the probability of the population being ill at the period of time being studied
DIFFERENCES BETWEEN INCIDENCE AND PREVALENCE
Which is more useful in acute and which is more useful in chronic cases
Acute: incidence
Chronic: prevalence
WHAT IS PERSON-TIME ?
Person-time is an estimate of the ______________ in days, months or years that all persons contributed to a study.
actual time-at-risk
PERSON-TIME
In certain studies people are followed for different length of time, as some will remain disease-free longer than others.
A subject is eligible to contribute person- time to the study only so long as that person ——————— and therefore still _________________
remains disease-free
at risk of developing the disease of interest.
By knowing the __________ of disease and the ———— contributed to the study, an investigator can calculate the incidence rate of the disease, or how quickly people are acquiring the disease.
number of new cases
person-time-at-risk
In addition, both risk and odds assume that the population at risk is followed over a specified time period, and that all those who are included at the beginning of the time period are counted at the end of the period. This is called a _________ population or a ________. However, you might want to look at incidence in a _______ or _________ population over a longer period of time during which people __________________ at different points.
In this situation people in the group may have been at risk for different length of time. Therefore, instead of counting the total number of people at the start of the study, the ________________________ needs to be calculated. This is known as the ____________.
CLOSED; COHORT
Dynamic or Open
enter and exit the population at risk
time that each individual spends in the study before becoming a case
person-time at risk
The term “_______ RATE” is often used instead of incidence during a disease outbreak in a ________ population over a (short or long?) period of time.
ATTACK
narrowly-defined
Short
The attack rate can be calculated as the ____________ and divided by the ___________.
number of people affected
number exposed
SECONDARY ATTACK RATE
Secondary Attack Rate is an important measure of __________.
communicability
SECONDARY ATTACK RATE
This rate measures the occurrence of a _____ disease among ________ persons who have been _________________.
contagious; susceptible
exposed to a primary case.
SECONDARY ATTACK RATE
This is defined as the number of exposed person ___________ within the _______________ following _______________
developing the disease
range of incubation period
exposure to primary case.
SECONDARY ATTACK RATE
SAR = _________________/ _____________ x 100
No. of exposed developing disease within the range of incubation period
Total no. of exposed or susceptible contacts
Secondary attack rate
It can also be defined as the no of additional cases among contacts of a primary case within the maximum incubation period/total no of susceptible contacts x 100
T/F
T
Secondary attack rate
The denominator more specifically restricted only to ________ if means are available to ____________
susceptible contacts
distinguish the susceptible from the immune
Secondary attack Rate
Primary case is excluded from both numerator and denominator
T/F
T
Secondary attack rate
This rate is used to measure the ________________ and is usually applied to closed groups such as ________,________, or _______ where it can reasonably be assumed that ______________________.
spread of infection
household, classroom or dormitory
all members were indeed contacts.
FACTORS INFLUENCING PREVALENCE
INCREASED BY:
(Shorter or Longer?) duration of the disease
Prolongation of life of patients ___________
______ease in new cases (____ease in incidence)
____-migration of cases
____-migration of healthy people
___-migration of susceptible people
Improved ___________________ which leads to __________
Longer ; without cure
Increase ;increase
In; Out; In
diagnostic facilities ; better reporting
FACTORS INFLUENCING PREVALENCE
DECREASED BY:
(Shorter or Longer ?) duration of the disease
(Low or High?) duration of the disease
(Low or High?) case-fatality rate from disease
____ease in new cases (____ease in incidence)
___-migration of healthy people
____-migration of cases
Improved cure rate of cases
Shorter; high
High; Decr; decr
In; out
CUMMULATIVE INCIDENCE
Cumulative Incidence is a simpler measure of the occurrence of a disease or health status. Unlike incidence, it measures _________________
the denominator only at the beginning of a study.
CASE-FATALITY RATIO
This ratio is useful in determining __________________.
how well the treatment program for a certain disease is succeeding
CASE-FATALITY RATIO
It is defined as
______________ due to a disease
—————————————- x K
_____________________ to the disease
where K is _________.
total number of deaths
total number of cases due
100
CASE-FATALITY RATIO
The period of time covered is arbitrary, depending on the nature of the disease, and it may cover several years for ___________ disease.
an endemic
CASE-FATALITY RATIO
Note that this ratio can be interpreted as the probability of _________________ and as such reveals the _________ of the disease.
dying following contraction of the disease in question
seriousness
MATERNAL MORTALITY RATE
The maternal mortality rate refers to the risk of __________________________________.
This important statistic is often neglected because _________________
mothers dying from causes associated with delivering babies, complication of pregnancies or childbirth
it is difficult to calculate accurately.
MMRate =___________________ in a given geographical area in a given year X 10n
—————————————-
__________________ in the same year
Number of maternal deaths from puerperalcauses
Number of women in the reproductive age group
LIFE EXPECTANCY
Life Expectancy is another summary measure of the health status of a population.
It is defined as the ___________________________________ if _______________________ continue.
It is not always easy to interpret the reasons for the differences in life expectancy between countries; different patterns may emerge according to the measures that are used
average number of years an individual of a given age is expected to live
current mortality rates
DEATH RATES
The death rate (or ___________) for all deaths or a specific cause of death is calculated as follows
CMR =
_______________ during a specified period X 10n
———————————————
________________during the same period
crude mortality rate
Number of deaths
Number of persons at risk of dying
The main disadvantage of the CMR is that it does not take into account the fact that ________________________
the chance of dying varies according to age, sex, race, socio-economic class and other factors
INFANT MORTALITY RATE
The Infant Mortality Rate is commonly used an indicator of ___________________.
the level of heath in a community
INFANT MORTALITY RATE
It measures the rate of _____________________.
The denominator being the _____________________________
death in children during the first year of life
number of live births in the same year.
CHILD MORTALITY RATE
The Child Mortality Rate ( _________ mortality rate) is based on _________________ and is frequently used as a _____________.
Injuries, Malnutrition and Infectious diseases are common causes of death in this age group.
under–5
deaths of children aged –4 years
basic health indicator
The under–5 mortality rate describes the probability (expressed per 1000 live births) of a ____________________________
child dying before reaching 5 years of age.
