This document discusses various research methodologies used in psychiatry research. It defines key terms like research, thesis, dissertation and describes different types of study designs - descriptive studies, surveys, case studies, correlational studies, case-control studies, cohort studies, randomized controlled trials, systematic reviews and meta-analyses. It also discusses formulating hypotheses and key steps in designing a research protocol like recruiting participants and addressing ethical considerations. Overall, the document provides an overview of important methodological concepts and approaches used in psychiatric research.
2. DEFINITION OF RESEARCH
WHO Health research methodology, 1992, a guide for training in
research methods:
“Research is a quest for knowledge through diligent search or
investigation or experimentation aimed at the discovery and
interpretation of new knowledge. Scientific method is a systematic
body of procedures and techniques applied in carrying out
investigation or experimentation targeted at obtaining new knowledge.
Here research and scientific methods may be considered a course of
critical enquiry leading to discovery of facts or information which
increases our understanding of human health and disease”
3. BASIC QUESTIONS BEFORE DOING RESEARCH
• Why? – To be of value to others
• Has it been done before? – Replication study vs original study
• Results? – Predictability vs Bias
• Implications of Research findings to clinical settings
• Advice – Colleagues as well as superiors
• Reviewing literature already published – Review article/Systematic
review
• Online search – Medline/PubMed/PsychLit/Sciencedirect
4. THESIS
• A proposition laid down as a theme to be discussed and proved. A
discussion to maintain and prove a thesis especially written or
delivered by a candidate for university degree- Ph.D
- OXFORD ENGLISH DICTIONARY
5. DISSERTATION
• Dissertation means “to discuss”.
• It is an academic activity laid down by a University for the partial fulfilment
of MD/Postgraduate degree.
• It is an exercise to train a PG student to plan, execute, evaluate, write and
report a scientific project.
• It is an in-depth study of a particular topic which contributes to new
information and knowledge in the field.
• A formal, often lengthy treatise (a book or writing of some particular
subject, one containing a methodical discussion or exposition of principles
of subject) or discourse, especially one written by a candidate for a
master’s degree.
6. DISSERTATION – WHY IS IT DONE?
• It is a pre-requisite or academic activity for acquiring a masters
degree or doctorial.
• Done to find out the truth which is hidden and which has not been
discovered yet.
• Contributes new knowledge to the existing one as scientific
knowledge develops in increments.
• As a profession to conduct research in various aspects.
• To solve an existing health problem.
• For the thrill and enjoyment of discovering a new fact.
9. • Descriptive research is used to describe characteristics of
a population or phenomenon being studied.
• It does not answer questions about how/when/why the
characteristics occurred. Rather it addresses the "what" question
(what are the characteristics of the population or situation being
studied?)
• Descriptive research cannot describe what caused a situation.
• Thus, descriptive research cannot be used to as the basis of a causal
relationship, where one variable affects another.
10. SURVEY
• A field of applied statistics, survey methodology studies
the sampling of individual units from a population and the
associated survey data collection techniques, such as questionnaire
construction and methods for improving the number and accuracy of
responses to surveys.
• A single survey is made of at least a sample (or full population in the
case of a census), a method of data collection (e.g., a questionnaire)
and individual questions or items that become data that can be
analyzed statistically.
11. SURVEY
• Survey samples can be broadly divided into two types: probability
samples and non-probability samples.
• Simple random sample (Probability sampling) is a subset
of individuals (a sample) chosen from a larger set (a population). Each
individual is chosen randomly and entirely by chance, such that each
individual has the same probability of being chosen at any stage
during the sampling process, and each subset of k individuals has the
same probability of being chosen for the sample as any other subset
of k individuals.
• Nonprobability sampling does not meet the above criterion.
12. SURVEY
• The most common modes of administration can be summarized as:
• Telephone
• Mail (post)
• Online surveys
• Personal in-home surveys
• Personal mall or street intercept survey
• Hybrids of the above.
• There is a distinction between one-time (Cross-sectional) surveys,
which involve a single questionnaire or interview administered to
each sample member, and surveys which repeatedly collect
information from the same people over time (Longitudinal surveys)
13. CASE STUDY
• A case study involves an up-close, in-depth, and detailed examination of a
subject (the case), as well as its related contextual conditions.
• Case studies appear with great frequency throughout popular works.
Nearly anyone with an education can lay claim to having done a case study
at some point in their life. Case studies also can be produced by following a
formal research method.
• One approach sees the case study defined as a research strategy, an
empirical inquiry that investigates a phenomenon within its real-life
context.
14. CORRELATIONAL STUDY
• A correlational study determines whether or not two variables are
correlated. This means to study whether an increase or decrease in
one variable corresponds to an increase or decrease in the other
variable.
• A correlation of –1 indicates a perfect negative correlation, meaning
that as one variable goes up, the other goes down. A correlation of
+1 indicates a perfect positive correlation, meaning that both
variables move in the same direction together.
16. • Analytic study: A statistical study in which action will be taken on the
process or cause-system that produced the frame being studied, the
aim being to improve practice in the future.
• Analytical studies are done in order to find out if an outcome is
related to exposure. They can take the form of observational (we
don’t influence the population), as well as
interventional/experimental (we influence the population, e.g.:
clinical trials; we give drugs). There are four main types of analytical
studies:
17. ECOLOGICAL STUDY
• The average exposure of a population is compared with the rate of
the outcome for that population.
• The data is obtained for several populations and the data are
examined for the evidence of an association between outcome and
exposure. The measure of association is usually the correlation
coefficient.
• The unit of analysis is the population, rather than the individual,
therefore the only conclusions we can draw relate to the population.
There is no possibility to make conclusions about the association
between exposure and outcome at the individual level.
18. CROSS-SECTIONAL STUDY
• They measure:
• Prevalence of exposure
• Prevalence of disease
• Information on exposures and disease status are obtained at the same
point in time, therefore these studies involve data collection at a defined
time. These studies are easy to be conducted and are quick and relatively
cheap.
• Cross-sectional studies measure prevalence, not incidence of disease.
• Temporal sequence of exposure and effect maybe difficult or even
impossible to determine. They differ from case-control studies in that they
aim to provide data on the entire population under study, whereas case-
control studies typically include only individuals with a specific
characteristic
19. CASE-CONTROL STUDY
• Case-control studies compare exposures in disease cases vs. healthy
controls from the same population. Researchers start with outcome
(event/disease) and measure prior exposure in cases and in controls
(comparison group).
• These studies can be used to evaluate many different exposures and
are relatively quick to be conducted. The main weakness is that they
can look at only one outcome. The reliability of the study depends
on the choice of controls. Data are collected retrospectively,
therefore they are relatively unreliable. The results are the odds
ratio.
20.
21. CASE-CONTROL STUDY
• Defining the cases and controls:
• Case: you have to decide a case before the start of the study. The case has to
fit in to two criteria.
• Diagnostic criteria.
• Eligibility criteria - only newly diagnosed cases within a specified period of
time than old cases.
• The criteria for inclusion and exclusion should be clearly specified.
• Sources of the cases – Hospitals or general population.
22. CASE-CONTROL STUDY
• Controls:
• They must be as similar to the cases as possible, except for the absence of the
disease, which is under study.
• Selection of controls:
• Crucial step in case-control studies
• Controls must be similar to the cases except for the absence of the disease under
study
• Sources of controls:
• Hospitals
• Relatives
• Neighbourhood controls
• General population
23. CASE-CONTROL STUDY
• Matching –
• Process by which we select controls in such a way that they are similar to
cases with regard to certain pertinent selected variables, which are known to
influence the out come of disease and which, if not adequately matched for
comparability, could distort or confound the results for eg. Age.
• Can also be used to evaluate the effect of a treatment by comparing the
treated and the non-treated units in an observational study or quasi-
experiment (i.e. when the treatment is not randomly assigned).
24. CASE-CONTROL STUDY
• Confounding factor –
• Associated both with exposure and disease; and is distributed unequally in
study and control groups
• In other words, confounding variable (also confounding factor, a confound,
or confounder) is an extraneous variable in a statistical model that correlates
(directly or inversely) with both the dependent variable and the
independent variable.
• Although associated with ‘exposure’ under investigation, by itself is a risk
factor for the disease
25. CASE-CONTROL STUDY
• Bias – A statistic is biased if it is calculated in such a way that it is only
systematically different from the population parameter of interest:
• Selection bias (Berkesonian bias)
• Confounding bias
• Recall bias
• Observer bias
26. CASE-CONTROL STUDY
• Odds Ratio –
• It is a key parameter in the analysis of case control studies
• A measure of the strength of the association between risk factor
and outcome
• Derivation of odds ratio is based on 3 assumptions-
• Disease under investigation is a rare one
• Cases are representative of those with disease
• Controls are representative of those without disease
27. CASE-CONTROL STUDY
• Advantages:
• Relatively easy to carry out
• Rapid and inexpensive (compared with cohort studies)
• Require comparatively few subjects
• Suitable to investigate rare diseases or diseases about which little is known
• No risk to subjects
• Allows the study of several different aetiological factors (e.g.,smoking,
physical activity and personality characteristics in smokers)
• No attrition problems, because case control studies do not require follow-up
of individuals into the future
• Ethical problems minimal
28. CASE-CONTROL STUDY
• Disadvantages:
• High chances for other types of bias
• Validation of information obtained is difficult or sometimes impossible
• Selection of an appropriate control group may be difficult
• We cannot measure incidence, and can only estimate the odds ratio but not
relative risk
• Not suited to the evaluation of therapy or prophylaxis of a disease
• Another major concern is the representativeness of cases and controls
29. COHORT STUDY
• A cohort study or panel study is a form of longitudinal study (a type
of observational study).
• A cohort is a group of people who share a common characteristic or
experience within a defined period (e.g., are born, are exposed to a
drug or vaccine or pollutant, or undergo a certain medical procedure).
• Cohort studies start with a group of exposed and a group of
unexposed individuals. These groups are then followed up over time
and assessed to see who develops the disease.
• The incidence rate of disease in the exposed group is then compared
to that in the unexposed group, therefore measuring relative
risk (RR).
30.
31. COHORT STUDY
• Advantages:
• Allow the possibility of measuring directly the relative risk of developing the
condition for those who have the characteristic, compared to those who do
not
• Allows for a conclusion of cause-effect relationship
• Because the presence or absence of the risk factor is recorded before the
disease occurs, there is no chance of bias
• Cohort studies are capable of identifying other diseases that may be related
to the same risk factor
• Unlike case-control studies, cohort studies provide the possibility of
estimating attributable risks, thus indicating the absolute magnitude of
disease attributable to the risk factor.
32. COHORT STUDY
• Disadvantages:
• Not always feasible
• Relatively inefficient for studying rare conditions
• They are very costly in time, personnel, space and patient follow-up
• Sample sizes required for cohort studies are extremely large, especially for
infrequent conditions; it is usually difficult to find and manage samples of this
size
• The most serious problem is that of attrition. The higher the proportion lost
(beyond 10-15%), the more serious the potential bias
• There may also be attrition among investigators who may lose interest, leave
for another job, or become involved in another project.
34. RANDOMIZED CONTROL TRIAL
• A randomized controlled trial is a type of scientific experiment,
where the people being studied are randomly allocated one or other
of the different treatments under study.
• The RCT is often considered the gold standard for a clinical trial.
• RCTs are often used to test the efficacy or effectiveness of various
types of medical intervention and may provide information about
adverse effects, such as drug reactions.
• Random assignment of intervention is done after subjects have been
assessed for eligibility and recruited, but before the intervention to be
studied begins.
37. • A systematic review is a research study that collects and looks at
multiple studies.
• Researchers use methods that are determined before they begin to
frame one or more questions, then they find and analyse the studies
that relate to that question.
• Systematic reviews of high-quality randomized controlled trials are
crucial to evidence-based medicine.
40. • The basic tenet of a meta-analysis is that there is a common truth
behind all conceptually similar studies, but which has been measured
with a certain error within individual studies.
• Meta-analysis can be thought of as "conducting research about
previous research.“
• Meta-analysis can only proceed if we are able to identify a common
statistical measure that is shared among studies, called the effect size,
which has a standard error so that we can proceed with computing
a weighted average of that common measure.
41. • Meta-analyses are often, but not always, important components of
a systematic review procedure.
• For instance, a meta-analysis may be conducted on several clinical
trials of a medical treatment, in an effort to obtain a better
understanding of how well the treatment works.
42. HYPOTHESIS
• Carl Popper’s view was that science exists to disprove hypotheses
rather than to prove them.
• Thus no hypothesis can be said to be right; the best hypothesis is the
closest approximation to the truth that we have at present, but there
is always the possibility that it will be replaced by another at a later
date.
• Hypotheses that are tested in scientific research are usually null
hypotheses (i.e. they predict a negative result).
• If a null hypothesis is disproved, then it is reasonable to entertain the
opposite (positive) hypothesis until it is tested again.
43. HYPOTHESIS
• Hypotheses must be precisely formulated questions rather than vague
statements.
• Vague hypothesis: ‘Does psychotherapy help patients with anorexia
nervosa?’
• Precisely formulated hypothesis: ‘Does psychotherapy in the form of
cognitive therapy, when given for 10 weeks, lead to a significantly greater
weight gain in patients with anorexia nervosa compared with those not
receiving cognitive therapy?’
• Null hypothesis: ‘There is no difference in the weight gain of patients with
anorexia nervosa when treated with cognitive therapy compared with a
control procedure’.
44. QUESTIONS RELATED TO STUDY DESIGN
• Is the objective of the study clearly and sufficiently described?
• Are clear diagnostic criteria used?
• Can you give a clear statement about the source of participants?
• Are you using concurrent controls rather than historical controls?
• Are the treatments well defined?
• Are you using random allocation, and, if so, what type?
• Will the trial be masked and, if so, how will this be ensured?
• Are there appropriate outcome measures?
• Using these measures, do you have defined criteria of outcome (particularly a
primary outcome)?
• Have you carried out a power calculation to help determine the most appropriate
sample size?
47. RECRUITING PARTICIPANTS
• When conducting prospective research, most researchers find that
appropriate patients seem to disappear just as the study is about to
start.
• Lasagna’s law predicts that the recruitment rate will fall by at least
half at just the time a study starts.
• In general the best way to deal with this is to allow for such
predictions in research planning.
• If the realistic prediction is that you can recruit 50 participants over 1
year, arrange your study so that your estimated prediction rate can be
doubled either by lengthening your recruitment time or by widening
your recruitment area.
50. COMPONENTS OF DISSERTATION
• ABSTRACT – SYNOPSIS OF THE ENTIRE RESEARCH PAPER/THESIS
• INTRODUCTION - ARTICLE (1-2 PARAGRAPHS) VS THESIS (3-4 PAGES)
• REVIEW OF LITERATURE – WHAT PREVIOUS RESEARCHERS HAVE SAID ON THE SAME TOPIC
• AIM AND OBJECTIVES – GENERAL VS SPECIFIC, INCLUDING NULL HYPOTHESIS
• MATERIALS AND METHODS – TYPE OF STUDY, PLACE OF STUDY, STUDY PERIOD, STUDY
POPULATION, SAMPLE SIZE, INCLUSION AND EXCLUSION CRITERIA, TOOLS OR INTERVENTION
USED, PROCEDURE, STATISTICAL ANALYSIS
• RESULTS – OBTAINED AFTER USING STATISTICAL SOFTWARE (SPSS/EPI-INFO) AS IT IS
• DISCUSSION – RESULTS OBTAINED IN THE LIGHT OF PREVIOUS STUDIES
• SUMMARY AND CONCLUSIONS – HIGHLIGHTS OF THE STUDY AND TAKE HOME POINTS
• LIMITATIONS – UNBIASED VIEW
• FUTURE DIRECTIONS – HOW STUDY CAN BE FURTHER IMPROVED
• BIBLIOGRAPHY – VANCOUVER/APA FORMAT
• CONSENT FORM – IN BOTH ENGLISH AS WELL AS THE LOCAL LANGUAGE
• ANNEXURE – ATTACHMENTS/ADDITIONS WHICH INCLUDES TOOLS USED