Epidemiology

Question 1

Describe some obesogenic environmental factors:

Answer 1

• Greater car dependence
• Less active travel
• Increased processed, high-sugar, high-saturated fat foods that are aggressively marketed

Question 2

What is evidence based practice?

Answer 2

• Use of current best evidence in making decisions about the care of patients
• Involves the integration of clinical expertise, best available evidence from systematic research and the incorporation of patient values and research

Question 3

What is the difference between efficacy and effectiveness?

Answer 3

Efficacy: intervention works in a research (clinical trial) setting

Effectiveness: intervention works in the real-life setting

Question 4

What is cost-utility analysis vs a cost-benefit analysis vs a cost-effectiveness analysis?

Answer 4

• Cost-utility analysis: weighs up the benefits of a treatment in terms cost of the treatment vs the gains in utilities such as quality of life and quantity of life (QALYs)
• Cost-benefit analysis: a more economical approach that compares the economic cost of the intervention vs the economic gain of achieving a health outcome
• Cost-effectiveness analysis: considers net costs vs net change in years of life

Question 5

What is an annual recurrent expenditure on healthcare in Australia and what are the greatest areas of healthcare expenditure?

Answer 5

• The annual recurrent expenditure on health care in Australia is $160 billion
• The greatest areas of health expenditure include: hospitals, medical services (includes costs covered by medicare) and medications (bulk paid by the federal government via the PBS)

Question 6

Explain the cost-effectiveness plane:

Answer 6

• On the x axis is net health loss to net health gain
• On they axis is net negative costs (cost saving) to net positive costs
• Most health interventions lead to a net health gain and a net positive cost
• A dominant intervention is when a health intervention leads to net health gain and net negative costs
• A dominated intervention is one that leads to net health loss and net positive costs

Question 7

What is allocative vs technical effieciency?

Answer 7

Allocative effeciency:

• Efficient distribution of available resources
• Considers opportunity costs

Technical efficiency:

• Efficient management of a single condition
• Considers cost-effectiveness

Question 8

How is it decided what to invest in in the healthcare industry?

Answer 8

• The efficiency of a health intervention is measured with incrememental cost-effectiveness ratio (ICER)
• ICER= net cost/net health effect
• The ICER is the gradient of the line
• Anything above the threshold line (historically dialysis) is considered cost effective and anything below the line is not considered cost effective

Question 9

What is the difference between a narrative and a systematic review?

Answer 9

• Systematic reviews have a focused clinical strategy, have a comprehenive methodology (search strategy, inclusion criteria, appraisal and synthesis) and all inferences are evidence based

Question 10

What are the advantages of systematic reviews?

Answer 10

1. Condensed: can access consolidated results of huge volumes of information
2. Objective: reduces risk of bias and error
3. Balanced: broad range of studies considered through search strategy
4. Verifiable: transparent process
5. Replicable: use structured methodology
6. Flexible: can be updated on a regular basis
7. Dynamic: in identifying under-researched areas and identifying new questions
8. Readable: easy to read and understand

Question 11

What are the disadvantages of systematic reviews:

Answer 11

1. Systematic reviews can be done badly
   - Inappropriate aggregation of studies
2. Systematic reviews often yield conflicting results
3. Systematic reviews include an element of judgement irrespective of method used

Question 12

What is a metaanaylsis?

Answer 12

• Optional element of a systematic review
• Involves statistically combining results from 2 or more studies
• Should only be done with studies with low heterogeneity
• Can be skewn if poor studies are used or reporting biases present an issue e.g. information vias

Question 13

How is publication bias assessed for?

Answer 13

• Done using a funnel plot
• Effect size on x axis vs sample size of trial on y axis
• Should read as an upside down funnel: as sample size goes up, variance should decrease
• If publication bias exists there may be a skewed plot or a hole in the funnel plot around null

Question 14

What is stigma?

Answer 14

• Co-occurrence of labeling, stereotyping, status loss and discrimination in a context where power is exercised
• Stigma becomes the grounds for inequity and disadvantage, social and economic exclusion etc.

Question 15

Why are mental illnesses so stigmatising?

Answer 15

• In order to be defined with “person-hood” and thus be deserving of moral consideration a being must be:
  1. Self-aware
  2. Capable of perceiving themselves as an entity persisting through time
• Capable of having preferences e.g. desire to keep living
• Mental illness compromises many of these elements that we value as human beings
• Negative stereotypes about mentally ill people being dangerous/violent