Lecture Wirawan Ing Desk Cross Sectional 2009

8/12/2019 Lecture Wirawan Ing Desk Cross Sectional 2009

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CURRICULUM CONTENT-1Apply diseases prevention in the communitybased on determinants of morbidity andmortality and their natural history KULIAHKE 1, 2, 3)

CURRICULUM CONTENT-4

Apply methods to Determine: a) RiskFactors/Cause and b) Effectiveness ofTreatment/Prevention/Intervention ofDiseases in the Community

KULIAH KE 14, 15, 17, 18, 19)


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1. Compare epidemiological design, e.g:cross-sectional, case-control, cohortandclinical studydesign to determine riskfactors and effectiveness of treatment,prevention, and intervention of diseases

in the community

Apply methods to Determine: a) Risk Factors/Cause and b) Effectiveness of Treatment/Prevention/Intervention of Diseases in theCommunity (KULIAH KE 14, 15, 17, 18, 19)


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3. Describe the application of clinicaltrialsto determine the effectiveness of

intervention, prevention, and treatmentof diseases

4. Describe the concept of patientvariability, variability in medical

research, variability of measurement,

both in individual and population level


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6.Describe sources of biasand how tominimize those biases in descriptive

research design, cross-sectional,

case-control, cohort, and clinical trialsfor research

5. Differentiate internal validity, externalvalidity, selection bias, information

bias, and confounding factors


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References

2. Cross-sectional:Sudigdo page 97

3. Cohort (prospective & retrospective)

Greenberg page 113

4. Case-control:Greenberg page 127

5. Clinical trials:Greenberg page 91

1. Descriptive:Greenberg page 45-63

7. Diagnostic Testing: Greenberg - 77

6. Variability and Bias: Greenberg - 141


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A. Descriptive study (how much, who,where, when)

1. Descriptive cross-sectional2. Descriptive longitudinal

B. Analytical study (why?)

1. Experimental (clinical and community trials)2. Observational

a) Cross-sectional analytic

b) Case-controlc) Cohort

Cohort prospective

Cohort retrospective


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Epidemiology Study Circle1. Descriptive study

(WHO, WHERE, WHEN)

2. Hypothesisformulation

3. Analytical study

to test hypothesis

4. Dataanalysis

New hypothesis


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Independent variable Dependent variable

Risk factors Disease incidence

CauseEffect

Coronary disease

ExamplesSmoking

Blood cholesterolHypertension

Anemia among

pregnant womenNutrition intake

Fe intake

Blood lost


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Descriptive study Analytical Study

1.To describe diseasedistribution in a popu-

lation (how much,

who, where, when)

1.To study theexplanation, whythe

disease distributed

like that

2.Notto study

relationship between

dependent and

independent variables(only to study disease

distribution)

2.To study relationship

between dependent

and independent

variables


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Descriptive study Analytical Study

3.As a foundation ofhypothesis

formulation

3.As a tool to answerthe hypothesis

4.Not usingcomparison group 4.Always usingcomparison

group/s


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Did investigator

assign exposures?

Experimental study

Random allocation?

Randomised

controlled

trial

Non-

randomised

controlled

trial

Observational study

Comparison group?

Analytical

study

Descriptive

study

Direction?

Cohort

study

Case-

Control

study

Cross-

sectional

study

Yes No

Yes No Yes No

Exposure

and

outcome

at the same

time

Exposure Outcome

Exposure Outcome


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A. Experimental

1. Randomized controlled trials

2. Non randomized controlled trials

B. Observational study

1. Descriptive study2. Analytical (explanation) study



Direction of observation

GROUPING-1


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A. Descriptive

1. Cross-sectional (prevalence study)

2. Longitudinal (incidence study)

B. Analytic (explanation study)

1. Clinical trials (experimental)2. Observational



Direction of observation

GROUPING-2


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CASE A850 women using IUD (intra uterine devices) in

Family Planning Clinics in Bali have been observedprospectively since the first day of IUD use. Before

IUD was inserted each woman was examined for

IUD contra indications such as urogenital

infections. After 5 years, the incidence of PID(pelvic inflammatory diseases) was analyzed. The

results showed that women-years incidence rate

among urban women was four time greater than

rural women. The incidence of PID also found five

times greater among women with more mobile

husband.


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The study design of CASE A is:

A. Community trials

B. Cohort prospective

C. Cohort retrospective

D. Descriptive cross-sectional

E. Descriptive longitudinal


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Ex: 500 sample

Coronary disease and blood

cholesterol are measured at

the same time

1. Cross-sectionalanalytic

2. Cohort3. Case-control

Healthy

populationand exposed

Healthypopulation

not exposed

How

manywill get

the

disease

Population

who has

the disease

Howmany

will get

the

disease

Population

who doest

have the

disease

How

manywere

exposed

Howmany

were

exposed

OBSERVATIONAL

STUDY


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Time

If coronary diseaseis measured at one pointof time descriptive cross-sectional (this is

a prevalence study of coronary disease)

If blood cholesterol is measured at one pointof time descriptive cross-sectional (this is

prevalence study of blood cholesterol)

BASED ON STUDY OBJECTIVES AND

MEASUREMENT OF VARIABLES

Ex: 500 sample


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Time

If dependent variable (for example: coronarydisease)is measured at one point and at the

same time with independent variable (for

example: blood cholesterol)and study

objective is understand the relationshipbetween these variables this is cross-

sectional analytic

Dependent and independentvariables at the same timeEx: 500 sample


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Time

If sample of population measured (examined)periodically, in certain length of time (1, 3, 5

years) in order to know how many of them will

get a disease this is a descriptive

longitudinal study we will get the incidence

of coronary disease by WHO, WHEN, WHERE



Ex: 500 sample


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Did investigator assign

exposures?

Intervention/eksperimental/clinical trials:

Example: 500 sample/patients with coronary

disease provided aspirin by the investigator

and another 490 sample/patientsprovidedplacebo (as a control group)

Observasional investigator only observe

people with risk factor (cohort)or with disease(case-control)or with disease and risk factor

at the same time (cross-sectional)or only one

group with out comparison (descriptive)

Yes

No

Monday &


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Did investigator

assign exposures?

Experimental study

Random allocation?

Randomised

controlled

trial

Non-

randomised

controlled

trial

Observational study

Comparison group?

Analytical

study

Descriptive

study

Direction?

Cohort

study

Case-

Control

study

Cross-

sectional

study

Yes No

Yes No Yes No

Exposure

and

outcome

at the same

time

Exposure Outcome

Exposure Outcome

Today

Monday &

Tuesday

Tuesday & Thursday


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References

2. Cross-sectional:Sudigdo halaman 971. Descriptive:Greenberg halaman 45-63

TO DAY WORK ON TASK 21 & 22)PAGES (STUDY GUIDE)

ARTICLE IN THE APPENDIXES (TheIncidence of Duodenal and GastricUlcers in Large Health MaintenanceOrganization)

Lecture Wirawan Ing Desk Cross Sectional 2009

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