Epidemiology and biostatistics
Study design, measures of risk, test accuracy and critical appraisal, plus key Australian health statistics.
High-yield points
Sensitivity = TP/(TP+FN); specificity = TN/(TN+FP); PPV and NPV depend on prevalence.
Likelihood ratio positive = sensitivity/(1 - specificity).
NNT = 1 / absolute risk reduction.
Relative risk comes from cohort studies and RCTs; odds ratios from case-control studies.
Screening biases: lead-time bias, length-time bias and overdiagnosis.
Confounding is controlled by randomisation, restriction, matching or statistical adjustment.
Coronary heart disease and dementia are the two leading causes of death in Australia; dementia is the leading cause of death in women.
India vs Australia
Where the answer the AMC marks correct differs from what’s usually taught in Indian MBBS.
| Aspect | India (MBBS)What you learn in MBBS | Australia (AMC)What the exam marks as correct |
|---|---|---|
| Core methods | Standard biostatistics and study design. | Largely the same: sensitivity, NNT, bias and study types are examined identically. |
| Data sources | Census, NFHS, Sample Registration System. | Australian Institute of Health and Welfare (AIHW) and the Australian Bureau of Statistics (ABS). |
| Burden of disease | Infections alongside rising non-communicable disease. | Chronic disease, cancer, mental illness and ageing dominate. |
| Health inequity | Gaps by region, caste and income. | The biggest gap is between First Nations and other Australians, e.g. life expectancy. |
Core methods
India (MBBS)
Standard biostatistics and study design.
Australia (AMC): what the exam expects
Largely the same: sensitivity, NNT, bias and study types are examined identically.
Data sources
India (MBBS)
Census, NFHS, Sample Registration System.
Australia (AMC): what the exam expects
Australian Institute of Health and Welfare (AIHW) and the Australian Bureau of Statistics (ABS).
Burden of disease
India (MBBS)
Infections alongside rising non-communicable disease.
Australia (AMC): what the exam expects
Chronic disease, cancer, mental illness and ageing dominate.
Health inequity
India (MBBS)
Gaps by region, caste and income.
Australia (AMC): what the exam expects
The biggest gap is between First Nations and other Australians, e.g. life expectancy.
The Australian context
Australian health data comes mainly from the Australian Institute of Health and Welfare (AIHW) and the Australian Bureau of Statistics (ABS). Unlike India, the major burden of disease is chronic non-communicable disease and ageing rather than infection, and the largest health gap is between Aboriginal and Torres Strait Islander people and other Australians.