Pre-clinical medicine
Epidemiology & biostatistics
Epidemiology studies how diseases are distributed in populations and what causes them; biostatistics provides the tools to analyse health data. Together they teach doctors how to read research and judge evidence.
Depth by stage, Pre-U → Consultant (details)
What is it?
Epidemiology asks who gets a disease, where, when and why. Students learn measures such as incidence and prevalence, and study designs such as cross-sectional surveys, case-control and cohort studies, and randomised controlled trials.
Biostatistics covers how data are described and tested: averages and spread, confidence intervals, p-values, and common statistical tests.
In Malaysia, students also learn about national surveys such as the National Health and Morbidity Survey (NHMS), which includes mental health indicators.
Why does a psychiatrist need it?
Psychiatry relies on evidence from trials and population studies to decide which treatments work and how common disorders are. Critical appraisal of research is examined in Malaysian master's programmes and in MRCPsych Paper B. Psychiatric trainees also complete a research dissertation, which requires a firm grasp of study design and statistics.
What level is expected at each stage?
Scale: 1. Aware → 2. Understands → 3. Applies → 4. Masters / Teaches. What the levels mean.
- Pre-UAwareAware of basic statistics from school mathematics.
- Pre-clinicalUnderstandsUnderstands study designs, measures of disease and basic statistical tests.
- ClinicalUnderstandsUnderstands how evidence shapes guidelines and how to interpret diagnostic tests.
- HousemanshipAwareAware; little time for research, but uses evidence-based guidelines.
- Medical officerUnderstandsUnderstands enough to read papers and start audits.
- Psych traineeAppliesApplies epidemiology and statistics in critical appraisal and the dissertation.
- Specialist / consultantAppliesApplies evidence routinely; supervises trainee research.
What are the key topics?
Measuring disease
- Incidence and prevalence
- Mortality and morbidity rates
- Disability-adjusted life years (DALYs)
- Population health surveys
Study designs
- Cross-sectional studies
- Case-control and cohort studies
- Randomised controlled trials
- Systematic reviews and meta-analyses
Bias and causation
- Selection and information bias
- Confounding
- Criteria for causation (Bradford Hill)
- Chance and statistical significance
Biostatistics
- Descriptive statistics
- Normal distribution, confidence intervals and p-values
- t-tests, chi-square tests, correlation and regression
- Relative risk, odds ratio, number needed to treat
Diagnostic tests and screening
- Sensitivity and specificity
- Positive and negative predictive values
- Screening programme principles
- Likelihood ratios (introduction)
How is it learned and assessed?
- Lectures and computer lab sessions
- Student research or community health projects
- MCQ and data-interpretation questions
- Critical appraisal in MMed exams and MRCPsych Paper B; dissertation in MMed
Typical textbooks and resources
- Epidemiology for the Uninitiated — BMJ Books
- Medical Statistics at a Glance — Petrie and Sabin (Wiley-Blackwell)
- How to Read a Paper — Trisha Greenhalgh (Wiley-Blackwell)
- Gordis Epidemiology — Elsevier
Titles are widely used examples; editions change. Use university libraries or legitimate purchases.
Common questions
Why does a psychiatrist need statistics?
To judge whether a study's results are reliable and whether a treatment really helps. Specialist exams test this directly, and trainees must complete a research project.
What is a randomised controlled trial?
A study in which people are randomly assigned to different treatments so that differences in outcome can be fairly attributed to the treatment. It is the main way new psychiatric medicines and therapies are tested.