introduction to research methods.ppt
TRANSCRIPT
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Introduction to
Health Research & Methods
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Research
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Research what is it all about?
Central to the scientific enquiry.
Seeing what others see and findingwhat others dont.
Purpose:to add to knowledge
that will better the lives of people
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Research - Definition
Research is a quest for knowledge through
diligent search or investigation orexperimentation aimed at the discovery and
interpretation of new knowledge WHO
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Research is a scientific
process
There is a need to demystify the scientific process.
Scientific Inquiry is basically a potentiation of commonsense ,which is one of the most equitably distributed
human gifts.
As Einstein said The whole of science is nothing morethan a refinement of everyday thinking.
In a sense ,most of us conduct some research in ourdaily life.(e.g) ,if we want to buy a car in a proper way, wecollect information about the models anddealers,analyse it then try to reach the scientific
conclusion on which one to buy.
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Health Research
Health most vital part of human life
Health research & Medical research
Cornerstone of all the advancements
Health for all or Millennium
Development Goals only through proper
research
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Health Research
what is it all about ?
Increase understanding of causal association
both etiologic agents and risk factors to disease.
To improve methods of diagnosis
To optimize therapy and management of the
sick.
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Research provides the reliableevidence
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Good research & Bad research
There is only one type of research - goodresearch .
Bad research does not deserve the name -Research
Badly done research is utter waste of time ,money and effort; it is unethical as it exposesresearch subjects to the inherent risk ofexperimentation with no reward to them ,to
others or communities
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Is Health Research a luxury?
Should Countries with scarce resources doresearch ?Yes
Because we are a poor country , wecannot afford not to do research .
(Jawaharlal Nehru) India cannot wait indefinitely for
development of new technologies for
health that are urgently required fortackling various diseases effecting thepeople of country Gulam Nabi Azad
Health research A vital investment
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Health research in India
Since more than 2000 years 1911 to 2011 (IRFA to ICMR)
DHR 2007
National Health Research Policy
Health research in India is poor: TheLancet *
Research to achieve healthcare for all in India
0.4% in 1988 to 1.8% in 2008*The Hindu, 04.04.2011
96% from 9 medical colleges only!
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Types of health research
Basic and applied
Empirical and theoretical
Qualitative and quantitative
Health research triangle
Biomedical
Behavioral
Health research
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Tools for health research
Epidemiology
Measures of disease frequency
Causations & Associations
Validity & reliability
Study designs etc.,
Biostatistics
Descriptive statistics
Sample size
Tests of significance etc.,
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Anatomy and physiology of
Research methods
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The anatomy
What it is made of?
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Anatomy of research
What questions to address?
Why are these questions important?
How is the study structured? Who are the subjects and how will they be
selected?
What measurements will be made? How large is the study and how will it be
analysed?
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Anatomy of research
What questions to address? Research question(s) / topic
Why are these questions important? Background and significance
How is the study structured? Epidemiologic approach Who are the subjects and how will they be selected?
Selection criteria; sampling
What measurements will be made?
Exposure; Outcome; Confounding variables
How large is the study and how will it be analysed? Hypotheses; sample size; analysis plan
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Research question
Translates into the objective(s) of the study Begins with general uncertainty about a health
issue
Narrows down to a concrete, researchable issue Research topic should be FINER*
Feasible
Interesting
Novel Ethical
Relevant*Hulley et al, 2001
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Example: Research question
General
Should people eat more fish?
Specific components
How often people eat?
Does eating fish lower risk of cardiovascular disease?
Is there a risk of mercurial toxicity from increasing fishintake in older adults?
Do fish oil supplements have the same effect oncardiovascular disease as dietary fish?
Which fish oil supplements do not smell like fish?
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Background and significance
Provide the context and rationale
What is known about the topic?
Why is the research question important?
What kind of answers will the study provide?
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Example: Significance
Regular consumption of fish in some
communities
Reports of reduced risk from eating fish
Certain communities do not like or eat fish
No evidence on the benefits of fish oil
supplements over eating fish
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Study designs
1. Different questions require different
types of Study Designs.
2. It is essential to understand the
structure of different Study Designs
3. Choosing the correct study design is
crucial to the success of the Research
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Study designs
Observe the events taking place in the
study participantsOR
Apply an intervention and examine its
effects on these events
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Study designs
Observe the events taking place in the
study participants
Observational studies
Apply intervention and examine its effects
on these events
Experimental studies
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*from International Union Against Tuberculosis and Lung Disease
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Examples of study designs
Designs Example
Cross-
sectional
Interview subjects about current and past
history of fish intake and relate them with
history of CHD
Cohort Measure fish intake at baseline and periodicallyexamine at follow-up to see if those who eat
more fish have fewer CHD events
Case-
control
Compare group of CHD patients with those who
do not have CHD and ask them about fish
intake
Clinical
trial
Assign randomly participants to receive fish oil
supplements or placebo, then follow them for
several years to observe the incidence of CHD
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Study participants
Selection criteria How are you defining your study population?
Inclusion criteria
Exclusion criteria
Sampling How are you selecting your study subjects?
What subgroup of your overall study population will bechosen to be your study subjects?
Will they be randomly selected from a large populationor will they be a convenience sample from theattendees of a particular clinic or hospital?
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Measurements
Which characteristics of the study subjects
are you going to measure?
Exposure variables
Outcome variable(s)
Confounding variables
variables that can confuse interpretation of
outcome
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Example: Measurements
Exposure variables
Age, race, gender; smoking
Types of fish; portion size; fried or baked; any
supplementation Outcome variable(s)
Heart attacks, strokes, quality of life;
Confounding variables Intake of red meat; income level; any otherdietary
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Statistical issues
Hypotheses
Sample size
Analysis plan
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Hypothesis
Re-phrase your study question so that it
provides the basis for testing the statistical
significance of findings
e.g., 50-69 year old women with CHD who
take fish oil supplements will have a lower risk
of myocardial infarction than those who do not
Purely descriptive studies do not requirehypothesis and do not involve statistical
testing
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Sample Size
How many study subjects will you need in
order to observe the expected outcome
with adequate precision?
Involves assumptions
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The physiology
How it works?
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Goal of research
Truth in theuniverse
Findings in
the study
Infer
Process of designing &
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Process of designing &implementing research
Sample
Target
population
Sampling Implementation
Sample
Selection Bias
Measurement
Confounding
Bias
Chance
Conclusions
Design
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Inferences
Internal validity
How well do your conclusions correctly describe
what actually happened in your study?
External validity How well do your conclusions generalize to the
population outside of your study sample?
Causality How well does your measurement(s) explain a
cause and effect relationship with the outcome?
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Internal and external validity
Sample
Population
Sampling InternalValidity
Sample
Selection Bias
Measurement
Confounding
Bias
Chance
Conclusions
ExternalValidity
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Example: Causality Strength of the association
The stronger the association observed between fish intake andCHD, the less likely it is due to error
Dose-response effect
Does the risk of myocardial infarction reduce with dose/duration
of intake of fish intake?
Lack of temporal ambiguity
Does exposure to fish intake precede the occurrence of CHD?
Consistency of findings
Are your findings similar to those of other studies?
Biological plausibility
Does it make sense in the context of current biological
knowledge?
Specificity of the association
Does fish intake reduces risk of other diseases?
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Errors in research
Random
Incorrect findings due to chance
Increasing the sample size increases the precision
of findings and decreases the likelihood of arandom error
Systematic
Incorrect findings due to bias Reducing the error with which subjects aresampled and measurements are made increases
the accuracy of findings
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Designing the study
Outline 1 page elements of the study
Protocol
5-25 +pages of details used for planning yourstudy and grant application
Operations manual Collection of procedural instructions,
questionnaires, and other materials Ensures uniform and standardized approach to
conduct the study with good quality control
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Research cycle
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Im quitecomfortable
with research
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References & Acknowledgment
Designing Clinical Research, 3rd ed. SB
Hulley et al. Lippincott Williams & Wilkins
2007
Epidemiologic Research. DG Kleinbaum et
al. John Wiley and Sons 1982
Thanks to Dr.P.Manickam, NIE