Presented at Alfaisal University Scholar Program in Research Excellence (ASPIRE) on October 8, 2021 by Dr Omar Hasan Kasule Sr MB ChB (MUK), MPH (Harvard), DrPH (Harvard) Professor of Epidemiology and Bioethics King Fahad Medical City.
WHAT KIND OF DATA WILL BE
COLLECTED, AND HOW MUCH?
· Definition of a variable: quantitative (discrete and continuous) and
qualitative (nominal, ordinal, ranked)
· Types of variables: independent, dependent, confounding
· Determine how much data to collect (target sample size) and the level of
precision
· When the data will be collected (month and year);
· How long data collection
will continue (duration of research);
· Where the data will be
collected (location, situation).
· Access and authorization of data collection: access to people
and organizations, access to events and settings, access to equipment, and access to documents and records. IRB approval does not guarantee access.
HOW WILL THE DATA BE COLLECTED?
· Record review
· Interview
· Questionnaire
· Observation
· Physical clinical
measurements
· Educational or
psychological tests
· Laboratory and radiological
· Environmental
SOURCES OF SECONDARY DATA
· Census data is a reliable
source of demographic, social, economic, and health information.
· Vital events are births,
deaths, Marriage & divorce, and some disease conditions.
· Routinely collected data: medical
facilities, life, and health insurance companies, institutions (like prisons,
army, schools), disease registries, and administrative records.
· Observational epidemiological
studies are of 3 types: cross-sectional, case-control, and follow-up/cohort
studies.
· Special surveys cover a
larger population than epidemiological studies and may be health, nutritional,
or socio-demographic surveys.
PRIMARY DATA COLLECTION BY
QUESTIONNAIRE
· Questionnaire design
involves content, wording of questions, format, and layout.
· The reliability and
validity of the questionnaire pilot tested
· Informed consent and
confidentiality must be respected.
· A protocol sets out data
collection procedures.
· Questionnaire administration: face-to-face interview, telephone, Computer-administered.
PHYSICAL PRIMARY DATA COLLECTION
· Clinical examination,
· Standardized
psychological/psychiatric evaluation,
· Measurement of
environmental or occupational exposure,
· Assay of biological
specimens (endobiotic or xenobiotic)
DATA MANAGEMENT
· Self-coding or pre-coded
questionnaires are preferable.
· Data is input as text,
multiple choice, numeric, date and time, and yes/no responses.
· Interactive data entry
enables the detection and correction of logical and entry errors immediately. Data
replication is a copy management service that involves copying the data and
also managing the copies.
· Data editing is the process
of correcting data collection and data entry errors.
· Data is validated and its
consistency is tested.
· Data transformation is the
process of creating new derived variables preliminary to analysis
DATA ANALYSIS
· Data analysis consists of
data summarization, estimation, and interpretation.
· Descriptive statistics are
used to detect errors, ascertain the normality of the data, and know the size
of cells.
· The tests for the association
are the t, chi-square, linear correlation, and logistic regression tests or
coefficients.
· The common effect measures
Odds Ratio, Risk Ratio, and Rate difference.
· Analytic procedures and
computer programs vary for continuous and discrete data
ASSESSING THE SUITABILITY OF THE
METHODS
· Will the methods produce
data that are relevant for addressing the research questions?
· Are the methods the best
available under the circumstances? Are there better alternatives?
· Will the methods work? Will
they do the job?
· Risk assessment: what can
go wrong? How can we detect it? Prevention and mitigation of risk.
ASSESSING THE FEASIBILITY OF THE
METHODS
· Feasibility is best tested
by a pilot study
· Resources availability
· Type of data: The use of qualitative or quantitative data:
What are their respective strengths? Which is better suited to the needs of
this particular research? Is a mixed-methods approach preferable?
· Depth or breadth of
data: Will a case study be better than a survey, or vice versa, in terms of the
particular research questions being looked at? Is there a need for depth of
focus or is there a need for data drawn from widespread sources?
· The validity of the
data produced: Will the data be accurate? Will they focus on the right issues?
Is the chosen method better than the alternatives in terms of getting honest
responses from participants?
· The reliability of
the method: Will the method(s) produce the same data if the same research is
repeated?
· The possibility of generalizing
from the findings: Can the findings be extrapolated to other
situations/examples? Is this possible and is it important? Is this crucial for
the research?
· The extent to which the
data are representative: Is it better to include all (or a sample) of a
population or will research along the lines of a case study be more suitable?
Are data based on extreme examples or special instances more valuable?
· The extent to which the
methods are objective: Is this possible bearing in mind the research
questions being addressed? How much does it matter?
LIMITATIONS OF THE METHODS
· Limitations associated with
the methods; and
· Limitations caused by
circumstances beyond the control of the researcher.
· Limits to how far the
findings lend themselves to being generalized to other situations/examples;
· Limits to the possibility
of checking the accuracy of findings;
· Limits to the ability to
confirm that data comes from a representative sample of the research
population;
· Limits to objectivity
resulting from the role of the researcher in data collection and analysis.
· Restricted access to
significant sources of data;
· Restrictions arising from
the resources available (time and money);
· Limits to the sample size.
ETHICAL ISSUES
· Discuss likely issues and not
just mention will get IRB approval.
· Autonomy/informed consent.
· Confidentiality.
· Data protection regulations.
· Regulations about tissues
especially DNA analyses.