Health of Individuals and Populations
What you must understand
Health is more than the absence of disease; it is a resource for living shaped by physical, mental and social wellbeing. Learn the difference between individual health (personal biology, lifestyle, resilience) and population health (aggregated outcomes, distribution and equity). Know how health status is measured: incidence versus prevalence, morbidity versus mortality, life expectancy, disability-adjusted life years (DALYs), and infant mortality. Understand the social gradient - health improves as socioeconomic position rises - and the concept of health inequity (unfair, avoidable differences) versus health inequality (any measurable difference).
Traps in questions
- Confusing incidence (new cases in a period) with prevalence (all existing cases at a point).
- Treating all differences as inequities - only unjust, avoidable ones count.
- Describing Australia's health as uniformly good while ignoring Aboriginal and Torres Strait Islander peoples' outcomes and rural-urban gaps.
- Using DALYs as if they measure only death - they combine years lost to premature death with years lived with disability.
Worked example
A town of 10,000 reports 50 new diabetes diagnoses in a year and 400 people currently living with diabetes. Incidence = 50/10,000 = 0.5% per year; prevalence = 400/10,000 = 4%. If the rate in the wealthiest suburb is 2% and in the poorest is 7%, the gap is a potential inequity only if it is avoidable and unfair - explain the determinants (food access, income, education) before labelling it.
Rule of thumb
Always name the measure, the population and the comparison group; a statistic without these three is unusable in an exam answer.