Public Health

Question 1

What are the 4 quadrants?

Answer 1

Medical indications
Patient preferences
Quality of life
Contextual features

Question 2

Stages of change model

Answer 2

Precontemplation - Not yet acknowledging problem
Contemplation - Acknowledging problem, but not yet ready or sure of wanting change
Preparation - Getting ready to change
Action/willpower - Making change
Maintenance - Maintaining change

Question 3

Lead time vs length time bias

Answer 3

Lead time bias - Earlier diagnosis will give impression of longer survival compared to those of typical diagnosis age, but we have just found disease earlier. False impression that screening = better outcomes. (may still die at same age regardless)
[A diagnosed at 30, B diagnosed at 40, both died at 50]

Length time bias - A form of selection bias. Patients with slow growing tumours are more likely to be found in screening (Fast growing would already be in hospital being treated), since slow growing usually = asymptomatic. May lead you to believe that screening provided better outcome rather than the fact that their tumour is just slow growing