The Epidemiology of Non-infectious Disease (14-15)

Question 1

What famous association did Sir Richard Doll discover?

Answer 1

The association between smoking and lung disease
→ shocking as smoking was considered ‘normal’ in the 1940s/50s
→ questioning if the increase in lung cancer deaths caused or by chance

Question 2

What is a retrospective study?

Answer 2

(looks backwards)
→ examines exposures to risk/protection factors in relation to an outcome that is established at the start of the study
→ often criticised: error and bias are more common in retrospective studies

Question 3

What is a prospective study?

Answer 3

(looks forward)
→ examines outcomes during the study period and relates this to other factors such as suspected rick or protection factors
→ fewer potential sources of bias
→ designed your study to track exactly the data you need
→ takes a lot of time

Question 4

What were the findings of the prospective study of the effects of smoking on british doctors?

Answer 4

→ confirmed connection of smoking with lung cancer
→ showed how risk related directly to the extent of smoking
→ showed chronic bronchitis and coronary disease also linked to smoking

Question 5

What was the UK public health response to the confirmed connection between smoking and lung cancer?

Answer 5

Huge public health burden + disease people don’t contribute to economy
→ 25 years before tobacco taxed on health grounds
→ Doll disappointed by failure of other governments to follow tax and by a failure to ban tobacco advertising
→ UK smoking ban 2007

Question 6

How do lung cancer rates differ spatially/geographically in England?

Answer 6

North has higher rates e.g. North East 112.2/100,000
South has lower rates e.g. South East 66/100,000

Question 7

What is the risk factor for prostate cancer?

Answer 7

Age
→ incidence peaks at around 65yo
→ reduces after as people are dying of other things/reduced diagnosis due to general ill health

Question 8

How is prostate cancer diagnosed?

Answer 8

Prostate specific antigen (PSA)
→ a protein produced by normal and cancerous prostate cells
→ levels raise with age as prostate gets larger
→ levels above 3ng/mL are associated with an indication of prostate cancer

Question 9

What are the advantages of PSA testing?

Answer 9

Prostate specific antigen (PSA) testing
→ can detect prostate cancer before symptoms arise
→ possibly detecting fast-growing cancer at an early stage, where intervention could halt spread/prevent health problems
→ detection could indicate that an individual is high risk

Question 10

What are the disadvantages of PSA testing?

Answer 10

Prostate specific antigen (PSA) testing
→ raised PSA doesn’t always mean prostate cancer
→ low PSA doesn’t always mean no prostate cancer
→ raised PSA may lead to more tests - biopsy = pain, infection, blood in urine/semen
→ diagnosis with a slow-growing cancer which may have never caused problems/shortened life = unnecessary worry and treatment
→ treatments have side effects that affect daily life, invasive - is it worth while?
→ currently no screening for prostate cancer

Question 11

Was prostate cancer screening found to be beneficial?

Answer 11

No
→ there were increased diagnoses that would have otherwise been missed
→ mortality rates weren’t affected - no significant difference (confidence levels overlapped)
→ screening comes with: cost, repercussion of false positives/negatives, worry, ‘unnecessary diagnosis’

is it worth it?

Question 12

What are the risk factors for testicular cancer?

Answer 12

→ having testes
→ age (association with pubertal hormones?)
→ ethnicity
→ crypto-orchidism (undescended testes)
→ previous testicular cancer
→ inguinal hernia
→ HIV/AIDS
→ family history
→ height

Question 13

Why is cervical caner 100% preventable?

Answer 13

→ all girls can get the HPV vaccine free from NHS from age 12-18 (year 8 school, 2nd dose year 9)
→ HPV vaccine effective at stopping girls getting the types of HPV that cause most cervical cancers
→ as of 2019/2020 boys vaccinated too - to prevent spread

Question 14

What is non-communicable disease?

Answer 14

Disease of long duration and generally slow progression that are not passed from person to person
→ NCD are leading cause of death in the world (63% of annual deaths)
→ 80% of NCD deaths occur in low-middle income countries (spacial risk)

Question 15

What are risk factors of disease?

Answer 15

An aspect of behaviour or lifestyle, environment or genetic profile that is associated with an increase in the occurrence of a particular disease
→ characterised by modifiable and non-modifiable

Question 16

What are modifiable risk factors?

Answer 16

A factor that can be controlled or reduced, reducing the probability of disease
WHO prioritises:
→ physical activity
→ tobacco use
→ alcohol use/abuse
→ unhealthy diet

at an individual level can choose to change
+ how can government intervene at a population level (saves public health money)

Question 17

What are non-modifiable risk factors?

Answer 17

A risk factor that cannot be controlled
→ age
→ sex
→ race
→ family history (genetics)

Question 18

What is epidemiology?

Answer 18

The study of disease in a population
from such study you can estimate:
→ the prevalence of disease
→ the incidence of disease
→ factors associated with disease
→ factors likely to be causally associated
then hopefully do something about it

Question 19

What is diabetes?

Answer 19

A chronic illness that occurs either when the pancreas doesn’t produce enough insulin or when the body cannot effectively use insulin
→ insulin is a hormone that regulated blood sugar
→ hyperglycaemia (raised blood sugar) is a common effect of uncontrolled diabetes - over time leads to damage of body systems especially nerves and blood vessels
→ important public health concern - premature morbidity, mortality, reduced life expectancy and financial costs

Question 20

What are some complications with diabetes?

Answer 20

→ cardiovascular disease
→ kidney disease
→ retinopathy
→ neuropathy
→ amputation
→ sexual dysfunction
→ pregnancy complications
→ dementia

Question 21

What is type 2 diabetes?

Answer 21

Results from the body’s ineffective use of insulin (non-insulin dependent diabetes)
→ largely due to access body weight and physically inactivity
→ 1 in 10 people globally by 2045
→ 4.5mil people in UK living with diabetes
→ 1.1mil undiagnosed

Question 22

What is the cost of diabetes in the UK?

Answer 22

£23.7 billon (direct and indirect care)
→ 1 in 7 hospital beds occupied by someone with diabetes
→ sick people cannot work = cannot contribute to economy

Question 23

Why have high income countered had the lowest increase in diabetes prevalence?

Answer 23

High income = low change
→ not as big of a lifestyle changes
where as middle income have had a huge change to access