1. CRP I
RESEARCH DESIGN I
UNISBA
FACULTY OF MEDICINE
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MHS

2. Learning Objectives 1. Identify types of quantitative research
At the end of this lecture, the student should be able to :
1. Identify types of quantitative research
2. Discuss the differences between
non-intervention studies and
intervention studies
3. Describe non-intervention studies
4. Describe experimental studies
 5. Explain Clinical Trial
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3. TYPES OF RESEARCH Observational studies SURVEYS Cross-sectional
Descriptive
Longitudinal
Cross-sectional
Analytic
Longitudinal
EXPERIMENTS & QUASI-EXPERIMENTS
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4. Types of Quantitative Research
1. Non-intervention Studies
a. Descriptive Studies
b. Analytical (Comparative ) Studies
2. Intervention Studies
a. Experimental Studies
b. Quasi-experimental Studies
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5. 1. Non-intervention Studies
a . Descriptive Studies
The purpose of descriptive research is the exploration and description of phenomena in real life situation
This approach is used to generate new knowledge about concepts or topics that have limited or no research
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6. Systematic collection and presentation of data
to describe a certain situation
Scale of studies : Small or Large
Descriptive Case Study
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7. Cross-sectional Studies
Sample
Population (Census)
For example : - Physical characteristics
- KAP (Behavior) Study
- etc.
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8. b. Analytical (Comparative) Studies
To determine cause (etiology) or risk factors of a problem by comparing two or more groups
3 types of analytical studies :
1. Cross-sectional Studies
2. Case-Control Studies
3. Cohort Studies
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9. 1. Cross-sectional Studies
Focus : to compare
to describe
For example
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10. Describe disease pattern according to variables:
DESCRIPTIVE STUDIES
Describe disease pattern according to variables:
person
place time
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11. Descriptive studies provide data which are useful for:
 PUBLIC HEALTH ADMINISTRATORS :
- ENABLING THE MOST EFFICIENT
RESOURCES ALLOCATION.
- TARGET DETERMINATION FOR
PROMOTION/EDUCATIONAL PROGRAM.
 EPIDEMIOLOGIST
AS THE FIRST STEP TO DECIDE DETERMINANT OR RISK FACTORS WHICH CAN BE CHANGED TO REDUCE OR PREVENT DISEASE.
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12. DATA RESOURCES Census Vital statistics Employer health examination
Clinical records (Hospitals & Private practices)
National figures about food, drugs and other
products consupmtion.
These information are always available because they are collected routinely. In general descriptive studies are not expensive and do not take time compare to analytical studies.
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13. THE ADVANTAGES OF DESCRIPTIVE STUDIES :
- Describe disease patterns
- Perfom research question or hypothesis.
DESCRIPTIVE STUDIES ARE THE MOST FREQUENTLY USED AS EPIDEMIOLOGICAL DESIGN STUDIES.
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14. 2. Case report or Serial case
DECRIPTIVE STUDIES:
1. Correlation studies
2. Case report or Serial case
3. Cross-sectional surveys
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15. 1. CORRELATION STUDIES
To measure characteristics which represented a population to describe the relationship of a disease and several factors, such as:
- age
- calendar time
- utilization of health services
- food, drugs or other products consumption
- etc.
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16. Cigarettes per capita (1960)
300
280
260
240
220
200
180
160
140
120
100
CHD deaths per 100,000 population (1960)
Cigarettes per capita (1960)
Fig.5.1. Coronary heart disease mortality rates in the US per capita cigarette
sales in 1960, by state (44 states)
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17. Correlation coefficient (= r) -1 r  +1
Measurement used:
Correlation coefficient (= r)
-1 r  +1
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19. Can be done quickly and not expensive +
ADVANTAGES
Frequently used as the first step to study the probable relationship between a risk factor and a disease
Can be done quickly and not expensive
Frequently only used available information. -
DISADVANTAGES
Cannot related between exposure and disease
Cannot control the effect of confounding factors
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20. e.g. Daily intake of pork per capita Death Breast cancer 1964-1965
(28 countries)
There is a strong positive correlation between both variables and there is a possible association between both variables.
Increasing daily intake of pork, maybe only a clue of other factors which are related to breast cancer, such as: -Increase of intake of high fat food
-Decrease of vegetables intake
-Higher socio-economic status
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21. Strong positive correlation
Number of
color TV
per capita
Death
CHD
In several countries
Strong positive correlation
There is association with life style variables which can cause the risk of CHD, such as:
- Blood pressure
- Blood cholesterol
- Smoking
- Lack of exercises
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22. 20 15 10 5
France
Italy
Portugal
W.Germany
Per capita alcohol consumption (liters)
Spain
Austria
Switzerland
Australia
Belgium
New Zealand
Ireland UK
Canada
Sweden
USA
Finland
Netherlands
Japan
Norway
CHD death rates (males, years of age)
Fig Per capita alcohol consumption and CHD mortality rates in
20 countries in 1972
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23. CASE REPORT AND SERIAL CASE
To describe the experience of
a patient or a group of patients.
This study is used mainly in clinics to identify : unusual disease occurrence or patient histories.
From this study will formulate a new hypothesis.
Case report is one of the most common publication in medical journals.
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24. Case report documented unusual medical event and as
a first clue for identifying new disease or effect of certain exposure.
e.g.:
From one report ;
There is a hypothesis that oral contraception (OC) increases the risk of thrombo-embolism in veins.
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25. CASE SERIES
Is a collection of individual cases which can occur in a short period of time.
Historically, in epidemiology this design is important.
Frequently used as early method to identify an epidemic.
Investigation of individual activities in case series can formulate a new hypothesis.
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26. ADVANTAGES & DISADVANTAGES OF CASE REPORTS & CASE SERIES+
Is useful for getting hypothesis. -
CR : based on an experience of a person
the existing of a risk factor, can happen
CS : There is no control group.
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27. The state of exposure and disease
CROSS-SECTIONAL SURVEY
(= PREVALENCE SURVEY)
The state of exposure and disease
are measured at the same time among individuals in a certain population.
Risk factor
Disease
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28. CROSS-SECTIONAL SURVEYS
Give information and characteristics
of a disease with a snapshot of a health experience of a population at
a certain period of time.
Those information is very important for a public health administrator who are evaluating the health status and health service needs.
Contoh : SKRT
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29. DESCRIPTIVE DATA
PERSON
PLACE
TIME
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30. “Who has a disease?” Person characteristics : Age Sex Personality type
Religion
Marital state
Personality type
Race
Sosioeconomic :
Income
Education
Occupation
PERSON
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31. Age White men White women
Table 5-4. Death rates per 100,000 population from coronary disease in
the US , 1981, by age and sex
Age
White men
White women
< 1
2.0
1.8
1 – 4
2.2
5 – 14
0.9
0.8
15 – 24
2.6
1.6
25 – 34
9.4
4.2
35 – 44
60.6
16.2
45 – 54
265.6
71.2
55 – 64
708.7
243.7
65 – 74
1669.9
769.4
75 – 84
3751.5
2359.0
85 +
8596.0
7215.1
Source : US D.H.H.S., Health United States, 1984
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32. “WHERE is the rates of disease is higher or lower?”
PLACE
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33. Table 5-5 Geographic areas of highest and lowest incidence of
selected cancer sites, with ratio of incidence rates
Cancer site High incidence Low incidence Ratio
area area High-Low
Men Bladder United States Japan : 1
Colon United States Nigeria : 1
Esophagus Iran Nigeria : 1
Liver Mozambique England : 1
Lung England Nigeria : 1
Pancreas New Zealand India : 1
(Maori)
Prostate United States Japan : 1
(black)
Stomach Japan Uganda : 1
Women Breast British Columbia Israel (Non-Jewish) : 1
Cervix Colombia Israel (Jewish) : 1
Ovary Denmark Japan : 1
Uterus United States Japan : 1
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34. immigrants in California Sons of Japanese immigrants
Table 5-6 Relative risks of mortality from cancer from cancer of the stomach, liver and colon among Japanese men in Japan, Japanese immigrants to California, and sons of Japanese immigrants compared with white men in California, aged years
Cancer sites
Japanese in
Japan
Japanese
immigrants in California
Sons of Japanese immigrants
Stomach
8.4
3.8
2.8
Liver
4.1
2.7
2.2
Colons
0.2
0.4
0.9
Source : P. Buell and JE Dunn, Cancer mortality among Japanese Issei and Nissei of
California. Cancer 18:656, 1965
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35. MAP efficiently can show frequencies of a disease in several places.
DESCRIPTIVE DATA about PLACE can be presented efficiently by using illustration.
MAP efficiently can show frequencies of a disease in several places.
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36. “WHEN a disease is frequently high or low?”
TIME
Change of a disease occurrence is related to concept of epidemic.
Epidemic is related to increasing of disease occurrence in short period of time.
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37. German : introduce sleeping pill thalidomide 1957
1956
German : introduce sleeping pill
thalidomide
1957
One case report about congenital anomalies related to extremities and the digits.
1959
Increase of congenital anomalies during deliveries 200 times.
1961
At the mid of November formulated hypothesis: thalidomide is responsible for congenital anomalies.
In Germany, at the last of November 1961, thalidomide was suspended.
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38. Cyclic changes or Seasonal patterns
TIME (others) :
Cyclic changes or Seasonal patterns
Acute diseases or short latent period of diseases
- Secular trend
Chronic diseases frequency within several years or
decades.
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39. 2. Case-Control Studies retrospective Past Present Risk Factor (+)
Cases
Risk Factor (-)
Compare
Risk Factor (+)
Control
Risk Factor (-)
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40. 2. Case-Control Studies retrospective Past Present For example
Control Confounding Variables
matching
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41. 3. Cohort Studies Prospective Present Future ( Past )
or ( Retrospective )
Problem (+)
Exposed to
Risk Factor
Problem (-)
Compare
Problem (+)
Not exposed to
Risk Factor
Problem (-)
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42. 2. Intervention Studies
a. Experimental Study
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43. Population Sampling Experimental Group Control Group Sample
Randomization
Initial
Data Collection
Initial
Data Collection
Intervention (+)
Intervention (-)
Final
Data Collection
Compare
Final
Data Collection
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44. b. Quasi- Experimental Studies
After
Before
I (+)
Experimental
Group
Experimental
Group
Compare
I (-)
Control
Group
Control
Group
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45. DIAGRAM OF A BEFORE-AFTER STUDY
b. Quasi - Experimental Studies
Intervention
(+)
Experimental
Group
Experimental
Group
After
Before
Compare
DIAGRAM OF A BEFORE-AFTER STUDY
Pre-Test and Post-test Design without Control
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46. Clinical Trial Intervention to human subjects
Cause-and-effect relationship
Comparison of
Treatment A Treatment B
(Standard)
Randomized Controlled Clinical Trial (RCT)
Clinical Trial :
 Simple
 Complex
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47. Clinical Trial Dependent Independent variable variable Effect Death
Clinical events
Laboratory results
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48. PHASE 1 : The objective is to study safety
STAGE I : Study in Animals
STAGE II : Study in Human
Subjects
4 PHASES
PHASE 1 : The objective is to study safety
and tolerance to treatment
( subjects )
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49. STAGE II : Study in Human Subjects
PHASE 2 : The objective is to evaluate the most
effective system or dosage of treatment
( subjects )
PHASE 3 : The objective is to evaluate a new
treatment compare to an available treatment
Gold standard : RCT
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50. STAGE II : Study in Human Subjects
PHASE 4 : The objective is to evaluate a new
treatment which has been used in the
community, relatively for a long period of
time (about 5 years)
To study side- effects of a new treatment
= Post-Marketing Clinical Trial
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51. Clinical Trial
Design
Parallel design
Cross-over design
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52. Parallel design Experimental Group Effect ? R Pop Control Group
Pop = Population
R = Randomization
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53. Cross-over design Effect ? Effect ? EG EG Pop R Effect ? CG Effect ?
Washed out
Treatment
Treatment
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54. Getting valid results :
Parallel design
Most frequently used
Getting valid results :
- Randomization
- Matching
For acute/chronic diseases
2 groups or more
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55. What should be considered ?
Cross-over Design
Used for relatively stable chronic diseases
Advantage ?
Disadvantage?
What should be considered ?
- Carry-over effect
- Order effect
- Washed-out period ?
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56. Measure effect of variables
8 STEPS TO DO A CLINICAL TRIAL
Formulate Research
Problem & Hypothesis 1 5
Randomization
Determine
Research Design 2 6
Treatment
Determine
Research Subjects
Measure effect of variables 3 7
Measure basic
data of variables 4 8
Data analysis
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57. THANK YOU
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