# (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