Scientific Research Types of Research Research Methods

1. Scientific Research
The Fountain of
Knowledge
Professor Syed Amin Tabish
FRCP (London), FRCP (Edin.), FAMS, MD (AIIMS)
Postdoc Fellowship, Bristol University (England)
Doctorate in Educational Leadership (USA)

2. Scientific Research
 Research conducted for the purpose of
contributing towards science by the
systematic collection, interpretation and
evaluation of data and that, too, in a
planned manner is called scientific
research
It is a systematic collection, analysis and
interpretation of data to answer a question
or solve a problem

3. Classification of Scientific Research
 According to data collection techniques:
 Observational
 Experimental
 According to causality relationships:
 Descriptive
 Analytical
 According to relationships with time:
 Retrospective
 Prospective
 Cross-sectional

4. Classification of Scientific Research
According to the medium through
which they are applied:
Clinical
Laboratory
Social descriptive research

5. Classification Of Research
I. Descriptive research
 Case series
 Surveillance studies
II. Analytical research
 Observational studies: cohort, case control and cross-
sectional research
 Interventional research: quasi-experimental and clinical
research

6. Analytical observational research
OBSERVATIONAL
 Cohort Studies (Prospective, Retrospective and
Ambidirectional)
 Case-Control studies
 Cross-Sectional studies
INTERVENTIONAL RESEARCH (Experimental
Studies)
1. Quasi-Experimental Research
2. Clinical Research

7. Quantitative Research
 It is numerical, non-descriptive, applies statistics
or mathematics, and uses numbers.
 It is an iterative process whereby evidence is
evaluated.
 The results are often presented in tables and
graphs.
 It is conclusive.
 It investigates the what, where, and when of
decision-making.

8. Qualitative Research
 It is non-numerical, descriptive, applies to
reason, and uses words.
 Its aim is to get the meaning, and feeling and
describe the situation.
 Qualitative data cannot be graphed.
 It is exploratory.
 It investigates the why and how of decision-
making

9. Types of Questions
Academic “Basic”
 To add to our scientific
knowledge
Applied “Practical”
 To solve our practical
problems

10. Research: the Fountain of Knowledge
 A research problem refers to a difficulty that a researcher or
a scientific community or an industry or a government
organization or a society experiences. It may be a theoretical
or a practical situation. It calls for a thorough understanding
and possible solutions.
 Research provides the basis for many government policies.
For example, research on the needs and desires of the
people and on the availability of revenues to meet the needs
helps a government to prepare a budget.
 It is the fountain of knowledge and provides guidelines for
solving problems.

11. Step 1. Define a Research Area
Areas for
research are
very broad
and
overlapping
Selection depends on
Researcher’s
interest
Actual need
Available resource

12. 1. RESEARCH AREA
Cardiology

13. Step 2: Select a Research Topic
Researcher can
not study every
topic in the
selected area
Magnitude of
problem
Seriousness
Preventability
Curability
Feasibility

14. 2. RESEACH TOPIC
Ischemic Heart Diseases

15. Step 3. State the Research
Objectives?
 State objectives at
the beginning of
study
 State them clearly
 Objectives are stated
in two forms
Goal (general
objectives)
Specific objectives

16. Research Objectives Should Be
 Closely related to research questions
 Covering all aspects of the problem
 Very specific
 Ordered in logical sequence
 Achievable (take in account time & resource)
 Mutually exclusive (no repetition, no overlaps)
 Stated in action verb that can be evaluated

17. 3. GOAL (GENERAL
OBJECTIVES)
To contribute to prevention
of Ischemic Heart Disease

18. PRIMARY OBJECTIVES
To determine the effect of reducing
serum cholesterol (LDL) on the
occurrence of MI

19. SECONDARY OBJECTIVES
To describe the side effects of
lowering serum cholesterol

20. Step 4. Develop a Research
Question
 Before start, you make sure that
You has a research question
Question is clear and specific
Reflect the objective (s)
Has no answer by common sense
Has no answer in literature
Finding an answer will solve the problem of
the study

21. At this stage, review of
literature is very
important to ensure that
research question has
no answer

22. Review of literature is important
 Identify valid question
 Refine question(s)
 Avoid un-needed research
 Avoid duplication
 Avoid pitfalls of previous studies
 Provide scientific background
 Give rationale for study

23. Examples of Questions (1)
Description
 What is the incidence
of disease “D”?
 What is the prevalence
of disease “D”?
 What is the rate of
risk factor “F” in the
community?

24. Examples of Questions (2)
Etiology
 What is the cause of
disease “D”?
 Is exposure “E”
associated with disease
“D”?
 What is the risk factor
“F” associated with
the disease “D”?

25. Examples of Questions (3)
Diagnosis
 Is test “T1” better
than test “T2” in
diagnosis disease “D”?
 What the value of test
“T” in diagnosis
disease “D”?

26. Examples of Questions (4)
Therapy
 Is drug “A” better
than drug “B” in
treatment of disease
“D”?
 Is surgery more
effective than
conservative
treatment for disease
“D”?

27. Examples of Questions (5)
Prognosis
 What is the five-year
survival of patients
with disease “D”?
 What is the five-year
survival of patients
having disease “D”
after intervention “I”?

28. 4. RESEARCH QUESTION
Does hypo-cholesterolemic agent
“A” decrease the risk of MI ?

29. Step 5: Formulate a Hypothesis
It is a statement
of research
question in a
measurable
format
Hypothesis; must be:
 Based on scientific
background
 Translation of research
question
 Reflect the study design
 Use the study variable
 Test only one relationship
 Stated in measurable terms

30. Example for Formulating a Sound
Hypothesis
A prospective cohort study was designed
to answer the research question: “ is
hypercholesterolemia (HC) a risk factor
for coronary artery disease (CAD)?”

31. Examine the Following
Hypothesis
1. All subjects having HC will develop CAD
2. Dietary habits affect the risk of CAD
3. Rats given high fat diet will develop CAD
4. Atherosclerosis is associated with a high risk of
CAD
5. Increased serum cholesterol and triglycerides
and decreased HDL lead to increased risk f
CAD

32. 6. CAD is high among hypercholesterolemic
subjects
7. Subjects with HC have a higher risk of
developing CAD compared to subjects without
HC
8. The prevalence of CAD among HC subjects is
higher than that in subjects without HC
9. The probability of HC in CAD patients is
higher than in subjects without CAD

33.  Hypothesis (1) is refuted because it is not biologically
plausible
 Hypothesis (2) is refuted because it is not related to
research question
 Hypothesis (3) is refuted because it does not reflect the
study design (cohort not experiment)
 Hypothesis (4) is refuted because it does not use the
study variables
 Hypothesis (5) is refuted because it examine more than
one relationship. It is better to use separate hypothesis
for each studied association

34.  Hypothesis (6) can be refuted because it is
not stated in a measurable terms.
Expression “high” is very subjective
 Hypothesis (8) & (9) an be refuted because
they do not reflect the study design.
Although they fulfill all other criteria
 Hypothesis (7) is a sound hypothesis

35. 5. RESEARCH
HYPOTHESIS
Subjects with HC have a higher risk
of developing CAD compared to
subjects without HC

37. STUDY DESIGNS
 Classification
depends on role of
investigator in
controlling factors
under study
 Observational
 Ecological
 Cross sectional
 Case control
 Cohort
 Experimental/interven
tion
 Lab experiments
 Clinical trials
 Community interventions
 Quasi-experimental

38. 1. Ecological Study
 Sampling units are
groups
 Good source for
new hypothesis
 Problems
Ecological fallacy
Temporal
relationship

39. 2. Cross Sectional Study
 Data collected at a
single point in time
 No control group
 Prevalence rate can be
calculated
 Develop new
hypothesis
“Snapshot”

40. Prevalence vs. Incidence
 Prevalence
The total number of
cases at a point in
time
 Includes both new
and old cases
 Incidence
The number of new
cases over time

41. Example of a Cross-Sectional
Study
Study of association between garlic
consumption & CAD in the Family
Practice Clinic

42. Cross-sectional Study
Sample of Population
Garlic Eaters Non-Garlic Eaters
Prevalence of CAD Prevalence of CAD
Time Frame = Present

43. Cross-sectional Study
Garlic Consumption
+ -
C
A
D
+
- 90
10 90
10

44. Cross-Sectional Study
 Strengths
Quick
Cheap
 Weaknesses
 Weak evidence of
association
 Lack of
representativeness
 Absence of temporal
relationship
 No control of
confounders
 Prevalence-incidence
bias

45. 3. Case-Control Study
 Start with people who have disease
 Compare them with controls that do
not
 Look back and assess exposures

46. Case-Control Study
Patients with CAD
Patients w/o CAD
Present
Past
High Garlic Diet
High Garlic Diet
Low Garlic Diet
Low Garlic Diet
Cases
Controls

47. Do not eat
Eat garlic
ill not ill
49 49 98
4 6 10
Presentation of Case-control Study

48. Strengths
 Good for rare outcomes: cancer
 Can examine many exposures
 Useful to test hypothesis
 Fast & easy
 Cheap
 Provides Odds Ratio
 Minimal ethical problems
 No risk to participants
 No attrition problems

49. Weaknesses
 Cannot measure
 Incidence
 Prevalence
 Relative Risk
 High susceptibility to
bias
Misclassification
bias
Recall bias
Selection bias
Confounding bias
Temporal
relationship

50. Exposed
Unexposed
Source
population

51. Cases
Exposed
Unexposed
Source population

52. Cases
Exposed
Unexposed
Source population
Sample

53. Intuitively
If the frequency of exposure is higher
among cases than controls
Then the incidence rate will probably be
higher among exposed than non
exposed.

54. Case Control Study
Disease
Controls
Exposure
?
?
Retrospective nature

55. Marching towards outcomes
Cohort Studies

56. Cohort Study
 Begin with disease-free individuals
 Classify individuals as exposed/unexposed
 Record outcomes in both groups
 Compare outcomes using relative risk

57. follow-up period

58. Calculate
measure of frequency:
 Cumulative incidence
- Incidence
- Attack rate (outbreak)
end of follow-up

59. Unexposed
Exposed
Cohort Studies

60. Unexposed
Exposed
Incidence among
exposed
Incidence among
unexposed
Cohort Studies

61. Example of a Cohort Study
To see the effects of smoking on lung
cancer development

62. Prospective Cohort Study
Non-smoker
Smoker
No
cancer
cancer
cancer
No
cancer
Present Future

63. Smokers
Non-smokers
ill not ill
70 6930 7000
3 2997 3000
Presentation of Cohort Data

64. Data Analysis
Incidence rate
 Among smokers =
70/7000=10/1000
 Among non-smoker =
3/3000 = 1/1000
Relative risk =
10/1 = 10

65. time
Exposure Study starts
Disease
occurrence
Prospective Cohort Study
Exposure
Disease
occurrence
time
Study starts

66. Retrospective Cohort Study
Exposure
time
Disease
occurrence Study starts

67. Strengths
 Provides incidence data
 Establishes time sequence for causality
 Eliminates recall bias
 Suitable for rare exposure
 Allows for accurate measurement of
exposure variables

68. Strengths
 Can measure multiple outcomes
 Can adjust for confounding variables
 Can calculate relative risk
Dose response can be calculated

69. Weaknesses
 Expensive
 Time consuming
 Problems of attrition
 Cannot study rare outcomes (diseases)
 Some ethical problems

70. Weaknesses
 Exposure may change over time
 Disease may have a long pre-clinical phase
 Change of diagnostic criteria

71. Experimental Studies
Clinical trials provide the “gold
standard” of determining the
relationship between garlic and
cardiovascular disease prevention.

72. Clinical Trials
 Randomized
 Double-blind
 Placebo-controlled

73. Clinical Trial
Study
Population
Treatment
Group
Control Group
Outcomes
Outcomes
R
a
n
d
o
m
i
z
e

74. Clinical Trial
Study
Population
R
a
n
d
o
m
i
z
e
Garlic Pill
Placebo
CAD
No CAD
CAD
No CAD

75. Strengths
 Best measure of causal relationship
 Best design for controlling bias
 Can measure multiple outcomes

76. Weaknesses
 Ethical issues
 Unawareness of patients
 Withholding beneficial treatment
 Inability to refuse (prisoners)
 Potential side effects
 Co-intervention & contamination
 Feasibility problems

77. Small Group Tasks
 Elect a leader and a speaker
 Read your scenario
 Design a study to answer the research question
 Your funds are not unlimited!
 Briefly present your study to the large group
 Time:
 10 min for study design
 10 min for group presentations

78. Selection of Research Design
 Selection of the best
research design
depends on many
factors
 Purpose of study
 State of existing
knowledge
 Characteristics of study
variables
(exposure/outcome)
 Latency
 Feasibility

79. Research: The Fountain of Knowledge
 A research problem refers to a difficulty that a
researcher or a scientific community or an industry or a
government organization or a society experiences. It
may be a theoretical or a practical situation. It calls for
a thorough understanding and possible solutions.
 Research provides the basis for many government
policies. For example, research on the needs and
desires of the people and on the availability of revenues
to meet the needs helps a government to prepare a
budget.
 It is the fountain of knowledge and provides guidelines
for solving problems.