Week 2 Flashcards
differential bias
when there are errors in the exposure measurement that influence the event of interest
nondifferential bias
errors in the measurement of exposure are proportionally the same in all groups of interest
Clinical outcomes
measure treatment efficacy
represent professional or provider perspective
Economic outcomes
measure health-resource utilisation
represent societal perspective
Humanistic outcomes
measure impact of the disease and treatment
represent patient’s perspective
HRQoL
HRQoL
health related quality of life
individuals impact of disease and treatment, specifically the capacity to perform ADLs
mortality rate
incidence rate of fatal cases/total population at risk
crude death rate
number of deaths/number of persons at risk of dying
age-specific death rate
death rate for specific group of population
proportionate mortality
number of deaths from a given cause, per 100 or 1000 total deaths
infant mortality
rate of death in children during the first year of life
life expectancy
average number of years an individual of given age is expected to live if current mortality rates continue
age-standardised death rate
summary measure of death rate that a population would have if it had a standard age structure
cumulative incidence
number of new events in a specific period/number of people exposed to risk
prevalence
number of people with disease or condition at specified time/number of people in the population at risk at the specified time
acute
incidence
chronic
prevalence
case fatality
number of deaths from diagnosed cases in a given period/number of diagnosed cases of the disease in the same period x 100
person years
an estimate of the actual time at risk in years of all persons that contributed to the study
DALY
years of life lost (YLL) + years lost to disability (YLD)
YLL
number of deaths (N) x standard life expectancy at age of death in years (L)
YLD
number of incident cases (I) x disability weight (DW) x average duration of the case until remission of death (L)
Cumulative incidence
number of new events in a specified period / number of persons exposed to risk during this period
incidence rate
new cases in a defined period / total person years of disease in these people
prevalence
number of people with disease or condition at specified time / number of people in the population at risk of the specified time
RR used for
prospective studies: RCTs, cohort studies, cross sectional studies
RR
ratio of the probability of an event occurring in an exposed group to the probability of an event occurring in a unexposed group cumulative incidence (absolute risk) exposed / cumulative incidence (absolute risk) unexposed
RR=1
no difference in risk
RR>1
increased risk of that outcome in the exposed group
RR<1
reduced risk in the exposed group
AR aka
risk difference
AR
cumulative incidence exposed - cumulative incidence unexposed
ARP
(risk in exposed group- risk in unexposed group) / risk in exposed group x 100
PAR
incidence in general population - incidence in unexposed group
PAR%
(incidence in general population - incidence in unexposed group) / incidence in general population x 100
OR
retrospective studies: case control
ad/bc
HR
Hazard in the intervention group / hazard in the control group
HR=1
same amount of individuals experience the event in the intervention and control group
HR=2
two times the number of individuals in the intervention group are experiencing the event compared to the control group
HR=0.5
Half the number of individuals in the intervention group are experiencing the event compared to the control group
morbidity rate
incidence rate of nonfatal cases of a disease in the total population at risk during a specified time period
measured by DALY
point prevalence
prevalence literally at one point in time (e.g. right now)
period prevalence
prevalence measured over a (short) period of time (e.g. over the last year)
incidence
new cases in a defined period/ total person time (person years) of follow up
Converting RR to %:RR >1
(RR-1)X100
_% increase in risk
Converting RR to %: RR<1
(1-RR) x 100
_% decrease in risk
BP: 25th percentile or first quartile
the value below which the smallest 25% of observations fall and 75% of observations fall aboveit.
BP: 75th percentile or third quartile
the value where the 25% of observations fall above and 75% fall below it.
length of lower whisker
Q1-1.5xIQR
length of upper whisker
Q3+1.5xIQR
Parameter
data based on an entire population
gross pathology autopsy
Generally reserved for deaths that are unexpected, difficult to explain or suspicious
verbal autopsy
Technique used predominantly in the developing world where gross pathology autopsy is not possible
death certificates
Coroner assigns a cause of death after examination of the deceased
psychological autopsy
investigating the “true” cause of death in case of suicide
Absolute risk aka
baseline risk
absolute risk
number of outcome in group/number of total in group
absolute risk reduction
absolute risk exposed- absolute risk unexposed
intervention lowered risk by _
RR reduction (RR)
100- RR%
intervention reduces RR of outcome by _
AR ending
per 100 person years
if the variable was collected from a randomly selected sample
then the variable will also be a random variable
for norm dist
mean and SD
For anything skewed
median and IQR
for comparing two groups
median and IQR
segments of a pie chart arranged
descending order in clockwise direction
