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Presented at a Research Methods course at the Northern Area Armed Forces Hospital on December 28, 2020 at 3:40 PM by Professor Omar Hasan Kasule Sr. MB ChB (MUK). MPH (Harvard), DrPH (Harvard) Professor of Epidemiology and Bioethics, King Fahad Medical City
STEPS OF AN EPIDEMIOLOGICAL INVESTIGATION:
} Identifying and describing a
problem.
} Using the scientific method
to formulate and test hypotheses.
} Interpreting findings.
TWO TYPES OF EPIDEMIOLOGICAL STUDIES:
} Observational: get information on diseases and causes without
interfering with nature.
} Experimental: manipulate the causes artificially to see the effect on disease.
SOURCES OF EPIDEMIOLOGICAL INFORMATION FROM EXISTING DATA:
} Census.
} Medical facilities:
government and private sector.
} Health surveys.
} Vital statistics.
SOURCES OF EPIDEMIOLOGICAL INFORMATION FROM OBSERVATIONAL STUDIES:
} Observational studies allow
nature to take its course and just record the occurrences of the disease.
} Observational studies
describe the what, where, when, and why of a disease.
} Observational studies do not
interfere with the cause or the outcome.
SOURCES OF EPIDEMIOLOGICAL DATA FROM EXPERIMENTAL STUDIES:
} Experimental studies are
natural or true experiments.
} They involve deliberate
human action or intervention whose outcome is then observed.
} They have the advantage of
controlled conditions.
} They have ethical problems
with experimenting on humans.
TYPES OF OBSERVATIONAL STUDIES:
} Cross-sectional studies
including ecological studies and surveys.
} Case-Control studies.
} Follow-up (cohort) studies.
TYPES OF EXPERIMENTAL STUDIES:
} Laboratory-based experimental studies.
} Community-based experimental
studies.
} Randomized clinical trials.
} Non-randomized clinical
studies.
EXAMPLE OF RESEARCH BASED ON OBSERVATIONAL DATA: