Exam 1- HTH 450 Flashcards
Birth Rate Calculation
birth in year/ mid year population
(per 1000 per year)
denominator- men and women all ages
fertility rate calculation
birth in year/ mid year population
denominator- women of reproductive age (14-44-49)
per 1000 per year
death rate calculation
death in year/ mid year population
denominator- total population at mid year
per 1000 per year
average annual death rate calculation
death during period/n/mid year population
natural increase
birth rate decrease, death rate decrease dramatically, population still rises
human disease
interaction between host, environment, agent
direct transmission
human to human, respiratory, blood, saliva
indirect transmission
through a common vehicle(contaminated water, or air supply) or vector
Host factors
age, sex, region, customs, occupation, genetic
types of agents
biologic, chemical, physical, nutritional
environmental factors
temperature, humidity, altitude, crowding, housing, water, food, radiation, air pollution
clinical disease
characterized by signs and symptoms
nonclinical disease
inapparent
preclinical disease
not clinically apparent, but destined to progress to clinical disease
subclinical disease
not clinically apparent, not destined to become clinically apparent
persistent (chronic disease)
person fails to shake off the infection; polio
latent disease
infection with no multiplication of agent (genetic message is present in the host, not viable organism)
carrier status
individual harbors organism but is not infected as measured by antibody response or evidence of clinical evidence, but can still infect others; typhoid mary
endemic
disease within given geographical area
epidemic
disease that is widespread
pandemic
outbreak of global proportions
incubation period
interval from receiving infection to time of onset of clinical illness
determinants of disease outbreak
balance between number of people in population susceptible and at risk of disease and not susceptible
3 critical variables for incubation period
when did exposure take place, when did disease begin, what was incubation period of disease
attack rate
number of people at risk & illness develops/ total number of people at risk
epi curve
visual display of onset of illness among cases associated with outbreak
in epi curve, you can see– (5) things
distribution of cases over time, outliers, magnitude of outbreak, inferences about outbreak of pattern of spread, most likely time of exposure
primary case
person who acquires disease from exposure
secondary cases
person who acquires disease from exposure to primary case
secondary attack rate
attack rate in susceptible people who have been exposed to primary case
questions asked exploring case of disease
who, when, where
three types of measures for morbidity
ratios, proportion, rate
ratio
two separate and distinct quantities, neither being included in the other
proportion
numerator number is included in the denominator and denominator includes entire population at risk
rate-
frequency of occurrence of phenomenon, specific period of time
prevalence
number with disease in population at specified time/ people in population at that time
point prevalence
existing cases at specific time/ total population at midyear population
period prevelance
(old + new cases) in time period/ midyear population
incidence
number of NEW cases of disease that develop in population over specified time interval
cumulative incidence
period of time during which all of the individuals in population are considered to be at risk for the outcome- number developed disease during time period of _ years
incidence rate
denominator consists of sum of the units of time that each individual was at risk and was observed
NEW CASES of DISEASE
Incidence Rate
WITH DISEASE
prevalence rate
Cumulative incidence Formula
number of new cases/population at risk
Incidence Rate Formula
Number of new cases/ population at time
point prevalence
currently have disease
period incidence
have you had disease in certain time period
cumulative index
ever had disease
passive surveillance
available data on reportable diseases
active surveillance
project staff are recruited to carry out surveillance program
person time
sum of the units of time that each individual was at risk and was observed
annual mortality rate formula
total number of deaths from all causes in 1 year/number of persons in population at midyear
case fatality formula
individuals dying during specified period of time after disease onset or diagnosis/ # of individuals with specified disease
Years of Potential Life Lost
age of death subtracted from 75
standardized mortality ratio
observed number of deaths per year/ expected number of deaths per year
direct age adjustment
standard population used in order to eliminate any differences in age between 2 or more populations
indirect age adjustment
often used when numbers of deaths for each age specific stratum are not available
standardized mortality ratio formula
observed # of deaths per year/ expected # of deaths per year
case control study
identifies those with or without disease, who exposed/not exposed
