(M) Analytic - Epidemiologic Approach Flashcards
Event of interest
disease or death
Outcome
should proceed before the outcome
Exposure
Health-related event of interest
Outcome
death, disease condition like AIDS
Outcome
when someone got pregnant, whats the outcome and determine exposure
Exposure - tite, and fertilization of sperm with egg cell
outcome - blessing
blessing - anak
Having, or being exposed to, a potential cause or risk factor for disease or other outcome
Exposed
being a smoker or having sex with someone who has an STI
Exposed
Not having, not being exposed to, a potential cause or risk factor for disease or other outcome
Unexposed
Individuals that are disease positive
Cases
Individuals that are disease negative
Controls
Test the hypothesis of relationship between at minimum, two variables
Analytic Studies
what are the 2 variable that concerns with ANALYTIC studies
- one independent variable (exposure)
- one dependent variable (disease)
Analyitc studies - T or F
There is a comparison between comparator group (exposed and unexposed; positive and negative etc..)
T
Determine the factor, and outcome
Hypothesis – Is smoking related to hypertension?
- Factor – Smoking
- Outcome – Hypertension
in cross sectional what comes first. population or selected sample
Population
Cross-sectional
other name for it
Prevalence study
cross - sectional
Exposure and Outcome are measured at
One-point in time
sabay
Cross-sectional
if one point at a time, what will be the weakness?
Exposure should come first before outcome
– which means we cannot actually determine which came first
Cross-sectional
what are the categories?
- With Exposure, With Outcome
- With Exposure, Without outcome
- Without Exposure, With outcome
- Without Exposure, Without Outcome
Uses of Cross-sectional Study - T or F
Estimate burden of disease (prevalence)
T
Uses of Cross-sectional Study - T or F
Establish baseline data
T
Uses of Cross-sectional Study - T or F
Determine association between non-existing variables
F
Coexisting Variables
Cross-sectional
What are the 2 analysis
- Measures of Disease Occurence
- Measure of Association
Cross-sectional: Analysis
under measures of disease occurrence
- Prevalence in the population
- Prevalence among exposed
- Prevalence among unexposed
Cross-sectional: Analysis
under measure of association
Prevalence ratio
Advantages of cross-sectional studies
- Resource-eficient
- Does not suffer from attrition
- Generalizable
Disadvantages of cross-sectional studies
Difficult to establish causality
why is it hard to establish causilty using cross-sectional?
Temporal ambiguity between exposure and outcome: Which came first?
temporal ambiguity is also a concern for ecological studies
if u see this card
go over the formula for prevalence proportion and Prevalence ratio
PR = 1
Exposure is not associated with the outcome
Numerator = Denominator
The ratio = 1, no relationship.
no relationship with exposure and outcome
PR < 1
Exposure variable negatively associated with the outcome
Unexposed > Exposed
The ratio: < 1
the exposure variable is protective of the disease
Unexposed > Exposed; The ratio = < 1
PR > 1
Exposure variable positively associated with the outcome
Exposed > unexposed
The ratio: > 1
prevalence of the disease is higher among the exposed than among the unexposed
the ratio is > 1
T or F
The exposure variable is a risk factor to the disease
True
what is the PRINCIPLE in a cohort study?
Exposure First, then A follow up
- the follow up is to know if there is a CONCERNED OUTCOME
This approach is suitable in determining the influence of a particular risk factor in the causation of an event, such as a particular disease.
Cohort Study
Begins with the identification/selection of a group exposed to a risk factor, and a comparable group not exposed.
Cohort Study
In cohort study Both groups are then observed if they will develop the ?
sickness
if mag kaka cancer sila or what disease they were exposed to
what should be the characteristic of the group in a cohort study?
Distinct set of characteristics; secondary to:
* Common setting
* Common experience
Refers to the secular change of disease frequency in a group as influenced by membership in that particular group.
Cohort Effect
Exposure is measured at the present time and the participants are followed up to measure Outcome at a future time
Cohort Study
other names for cohort study
- Follow Up Study
- Longitudinal Study
- Incidence Study (something new; positive sa disease)
Types of Cohort Study
- Prospective/concurrent
- Retrospective/non-concurrent
- Ambispectibe
Types of cohort
starts at the beginning
Prospective/concurrent
Types of cohort
starts at the end(future) of the study
Retrospective/non-concurrent
Types of Cohort
mixed of both
Ambispective
Uses of Cohort Study - T or F
Calculate risk of developing disease
T
Uses of Cohort Study - T or F
Establish the temporal relationship between study variables
T
Uses of Cohort Study - T or F
Expedient in examining single outcomes
F - MULTIPLE
Uses of Cohort Study - T or F
Practical in studying rare exposures
T
Cause there is already a established person with the disease, just need to retrospective the exposure and not randomly try to guess which exposure lead to the outcome
Cohort Study: Analysis
what are measures under this?
- Measures of Disease Occurrence
- Measures of Association
Cohort Study
under the measure of disease occurrence
- Incidence Proportions
- Incidence Rates
Cohort Study
under measures of association
- Risk Ratio
- Rate Ratio
Advantages of Cohort Study
- More likely to determine causality (as compared to a cross-sectional study)
- Followed the natural history of disease
At the start, those with the outcome of interest should be excluded.
Cohort Study
If they have sickness, out na sa study
Disadvantages of Cohort Study
- Resource-intensive
- Sufferes from attrition
If u see this card
Go over the formula for incidence proportion and Incidence Rate
Cohort Study
- Describes the average risk for developing a disease condition
- More useful in determining etiologic/risk factors of diseases more than prevalence proportion
Incidence proportion
Cohort Study
- Describes the speed at which new cases occur
- “Time at risk”
Incidence Rate
period or duration at which each person is vulnerable (“at risk”) of developing the disease
“Time at risk”
Relative Risk is also known as?
- Risk Ratio
- Rate Ration
*
Cohort Study
if comparing incidence proportions
Risk Ratio
Cohort study
if comparing incidence rates
Rate Ratio
RR > 1
Exposure variables is a risk factor
shows an association
RR > 1
conclusion can be read “those with the exposure were more likely to develop disease.”
RR > 1
exposure variable is protective factor
RR < 1
T or F
OR is just an estimation of the RR.
OR = odd ratio
True
The RR is a more powerful effect measure than the?
OR (ODD RATIO)
if u see this card
Go over the example for RISK RATIO yung mahaba
A type of study that attempts to capture the advantages of both the cross-sectional study and the cohort study
Case-Control Study
It tries to eliminate the temporal ambiguity of the cross-sectional study while at the same time shortening the duration of the study
Case-Control Study
Outcome is measured at the present time and Exposure of the participants in the past is estimated
Case-Control Study
Case Contol
1st step process
We select the cases from a target population.
Case Control Study
3rd Step
Then select another group of individuals without the outcome or disease as Controls
ex. Women without breast cancer of the reproductive age group
Case Control Study
2nd Step
Cases are a group of individuals with the outcome or disease
ex. Women with breast cancer of the reproductive age group
Case-control Study
4th Step
Go back in time (retrospective) to determine exposure in the cases and in the control
Case-Control Study
5th Step
Compares the exposure status among the cases and among the controls