Block 15 Flashcards
Bowel cancer is more common where?
The west: Western Europe, America
Oesophageal cancer is most common where?
Eastern Europe/Russia
Levels of what correlate well with colorectal cancer?
Fat consumption
What type of study can be used to explore environmental effects?
Migrant studies
Ex of a migrant study
Looking at Japanese men who migrated to Hawaii. Stepwise increase in lifetime CA risk from 1st to 2nd gen
What is confounding in a Japanese migrant study?
May not just be diet that changed - alcohol, smoking etc.
What % of cancer is caused by the diet?
30%
In the UK, what are the top 4 causes of cancer? in order
Smoking
Diet
Obesity
Alcohol
What type of study are best for looking at affect of diet?
Observational studies
Some problems with case control studies in diet and cancer:
Recall bias
Hard to measure diet
Early CA may influence diet
Problems with cohort studies in diet and cancer:
Measuring diet difficult
Takes a long time
General problems with observational studies:
Bias
Confounding
Ex of confounding in diet and cancer
Beta carotene. Thought to be protective for lung cancer, but seems to cause it. Confounders weren’t controlled properly (i.e. those who take in more beta carotene tend to smoke less/drink less)
Measures of diet:
Food disapperance data Household surveys 24 hr recall Food frequency questionnaires Diet diary
Pros of food frequency questionnaires:
- Easy to code and complete
- Captures usual diet
Cons of food frequency questionnaires:
- Doesn’t actually capture what people eat
- No portion size/energy intake
- People overestimate fruits/veg
Pros of diet diary
- Captures actually what people eat
- Portion size/energy intake
- More flexible, can track a lot of food
Cons of diet diary:
- Expensive and difficult to code
- Take effort to do
- Misrepresentation
- People may change diet when completing diary to make it easier
Aflatoxin is a what found it what
Fungal toxin found in cereals and peanuts
Aflatoxin is linked to what cancer?
Hepatic
Colorectal cancer is caused by
red meat
processed mat
overweight
alcohol
beta carotene is causative of what and protective of what
causative = lung cancer protective = oesophageal
Why is it 5 a day?
Evidence shoes 400g/day of fruit and veg is protective of cancer. Average portion is 80g
Evidence shows less that what fruit and veg is associated with increased cancer?
<200g/day
Important health promotion messages for cancer:
- Increase levels of physical exercise
- Don’t put on weight in adulthood
- Aim for BMI between 18-25
- Maintain safe levels of alcohol intake
- Increase intake of fruit and vegetables, at least 400g/day
- Limit intake of preserved and red meat
CDSS =
Clinical decision support systems
CDSS’s are designed to =
Aid decision making by taking into account resources, patient preferences and doctor’s skill set
CDSS may be based on
Computer based
Paper based
Examples of CDSS
Reminder systems
Diagnostic systems
Prescription systems
Ex of a reminder system
Systemone
What do reminder systems do?
Flash up on screen and remind for: screening, vaccination, testing, allergies, prescriptions
What do diagnostic systems do?
Model signs and symptoms against what we know epidemiologically
Examples of 2 diagnostic systems:
Ottawa Ankle rules
Well’s score
Ottawa ankle rules:
15% of sprains are fractures but not all require x-ray…used to reduce need for x-rays. ‘Should only x-ray if there is pain in the malleolar area’ – Prevents 85% of X-rays showing no fracture – so reduces the number of unnecessary X-Rays
Well’s score is for diagnosis of
DVT
Prescribing systems can give:
Advice on drug
Advice of dosage
Contraindications
CDSS can improve practitioner performance in:
Diagnosis
Disease management
Prescribing
Rates of vaccination, screening, health promotion etc.
Aspects of CDSS that are successful:
- Computer based
- Normal work flow
- Gives advice when and where decision is being made
- Recommendations for management not just assessment
Barriers to CDSSs usefulness/uptake
Increases workload
Practitioner has bad experience with IT in past
Affects doctor-patient relationship
Obscures responsibilities - loss of clinical autonomy
Give an example of how CDSS can aid shared decision making
Patient decision aids
Trials show patient decision aids can
Increase knowledge of condition
Be more accurate with their perception of risk
Reduce uncertainty over decisions
Alcohol consumption in Western countries has
Decreased
Alcohol consumption in eastern countries has
Increased
What % of people are abstainent
17%
What % of people are non-risky drinkers
59.2%
What % of people are drinking at an increasing risk
20%
What % of people are higher risk drinkers
4%
What % of people are binge drinkers
17%
What % of people are dependent on drinking alcohol
1%
Highest risk age in women for alcohol consumption
16-24
Highest risk age in men for alcohol consumption
45-64
Which region has the highest alcohol consumption
North East England
What age cohort are higher risk drinking than others
middle age
Rates of abstinence in what population are increasing?
Younger males and females (16-24)
Why might abstinence be increasing in younger people?
Increasing health consciousness
Other substances
Household income correlated to increased drinking how
Positively
In the alcohol harm model, alcohol can be looked at in terms of:
Volume
Pattern
Societal vulnerability factors for alcohol harm
Development level
Culture
Drinking context
Alcohol production, distribution and legislation
Individual vulnerability factors for alcohol harm
Age
Sex
Socioeconomic status
Familial factors
Recommenced alcohol threshold for increased risk
14 units a week
How to work out alcohol units
(vol in ml x %) / 1000
Alcohol harm paradox
People in most deprived areas drink less than affluent but harm is higher
Possible explantations for the alcohol harm paradox:
- Patterns of drinking
- History of drinking
- Confounding: diet, smoking, occupation etc.
- Access to health care
Most effective alcohol policy is to
Reduce affordability
Policies for alcohol:
Reduce affordability
Market regulation - change drinking behaviours
- Reduce hrs which alcohol can be serves
- brief interventions for at risk
Little evidence supports the effectiveness of what on reducing alcohol
Education
Barriers to brief interventions in primary care:
GPs don't want to go there Time Doc-patient relationship Skills and training Patient's reluctant to disclose/talk about
Over 85s account for what % of population and use how many beds?
2.2%
4x more
Levels of resource allocation
Macro
Micro
Macro level =
Strategic, societal
Micro level =
Clinical levels
Why should resources on a macrolevel be affected by age?
- Health care for older people is costly
- Fair innings argument
Fair innings argument =
Older people have already had a long life, younger people have not. Fairer for resources to be diverted from older people to younger people
Validity of an argument relates to
If premises are true, does conclusion follow
Soundness of argument related to
Are premises true?
Why might the fair innings argument be unvalid?
Conclusion doesn’t follow. Just because its fairer doesn’t mean we should reallocate resources - other things may be important
Why might the fair innings argument be unsound?
Premises are wrong - fairness isn’t a measure of fullness of life
Why should age not be a factor in allocating resources at a macro levels?
- Much of this burden doesn’t relate to age but costs of illness and incapacity in last years of life
- Even if costly, price worth paying for a society that treats members equally, respectfylly and with compassion
- Devalues the status of older people and caters to the values of a youth-orientated culture in which negative stereotyping based on age is prevalent
Health care providers make decisions on a microlevel based on:
Need/severity
Likelihood to benefit
Why should age be considered when allocating on a micro level?
- Age is relevant because older people are less likely to be responsive to treatment
Why should age not be considered when allocating on a micro level
- Chronological age isn’t a good predictor of responsiveness - biological age more important
- Discrimination
Name 2 laws/Regulators which prohibits age related discrimination in NHS
Equality Act (2010) GMC
Equality at (2010) protects how many characteristics?
9
Characteristics protected by equality act:
Age Sex Race Gender reassignment status Diability Religion or belief Sexual oreintationn Marriage or civil partnership status Pregnancy
Direct discrimination =
Direct difference in treatment based on characteristic
Indirect discrimination =
Seemingly neutral provision has harmful repercussions on an individual/group
Equation for QALY:
Utility x no of years in health state
An efficient health activity in terms of QALYs
Low cost per QALY
Beneficial health activity in terms of QALYS
Generates positive amount of QALYs
Why are QALYs good?
Addresses primary purpose of healthcare (well being)
Patient identify them as important
Used by NICE
Why might someone object to QALY assessments?
Difficulty measuring/bias
Unjust
Ageist
Why might QALY assessments be unjust:
- Double jepordy argument
- End of life care
- Number of lives over individual lives
Double-jeapordy argument =
People with pre-exisitng conditions will be treated worse on a QALY assessment
Why might QALY disadvantage end of life care
Based on number of years lives
Why might a QALY be ageist?
Indirect discrimination
Efficiency =
Obtaining the greatest output for a given set of resources
2 main types of efficiency
Technical efficiency
Allocative efficiency
How is the NHS funded?
General taxation
National insurance
Out of pocket charges
Largest lump of money goes to:
Hospitals
What is the principle of funding general practice?
Contractual arrangements between GPs and NHS
How are GP funding allocated?
Capaitation - per head
QODs
Enhances services (e.g. vaccines)
Other - e.g. pharmacy
How else can we fund a health service?
Out of pocket
Social insurance
Private insurance
Social insurance models, costs fall mainly on
Employment sector
2 main problems with private insurance models:
Adverse selection
Moral hazard
Adverse selection =
Private insurance tends to be more expensive the more likely you are to need healthcare
How to tackle adverse selection:
Universal insurance
Safety-nets
Moral hazard =
Consumer - more risks
Provider - un-needed work
Ways to help consumer moral hazard
Co-payments
Ways to help provider moral hazard
Regulations/guidelines
Efficacy =
Does an intervention work? (RCTs)
Effectiveness =
Does an intervention work in practice?
Technical efficiency =
Best way to use resources to best achieve an objective.
Ex of technical efficiency
To pass my exams, should I go to lecture or go to library and watch later?
Allocative efficiency =
Whether or how many resources should be allocated to objective
Ex of allocative efficiency =
How much time should I dedicate to passing exams and how much should I dedicate to going out?
Ex of some ‘costs’ in opportunity cost =
depression
pain
death
Why are markets good?
Meeting points between suppliers and consumers. Can provide a good way to achieve best exchnage of scarce resources
As price increases
Supply increases
Demand decreases
As price decreases
Supply decreases
Demand increases
When supply = demand
Both consumer and producer make best of their resources (efficiency)
Why might a market fail?
Not efficient
Not provide fair allocations
Why might a market not be efficient?
- Asymmetry in information (supplier-induced demand)
- Monopoly or cannot enter the market
- Transaction costs
Supplier induced demand
Demand increases/is there just becuase it is provided
How to make a market more efficient:
- Empower patients or regulate
- Subsidise new entrants to market
- Minimise complexity of transaction costs
Economic evaluation is the
comparative analysis of courses of action in terms of both costs and consequences
Function of NICE =
provides recommendations of the use of new and existing medicines and treatments within NHS based on clinical and economic evidence
What is a partial economic evaluation?
Only considers costs
Only considers consequences
Only looks at 1 option
A full economic evaluation must =
Look at costs and consequences
Look at 2 or more alternatives
Methods of economic evaluation:
Cost-effectiveness analysis
Cost-utility analysis
Cost-benefit analysis
Costs are measured as
£
Outcomes measured in CEA
Single common variable/natural clinical unit
Outcomes measured in CUA
All effects
How are outcomes values in CUA
QALYs
Outcomes measured in CBA
All effects
How are outcomes valued in CBA
Monetary terms
2 ways economic evaluations can be conducted?
Alongside RCTs
Rely on existing data/studies
Example of evaluations which rely on existing data
Technology assessment reviews (NICE)
Costs which may be considered in economic evaluation:
Costs to health sector
Costs to patients and family
Costs onto other sectors
Costs to health sector
- treatment
- staff
- time
- facilities
- other operational costs
Costs to patient and family
- worry/stress
- loss of productivity
- out of pocket expenses: transport
Ex of costs to other sectors
Social services
Consequences that can be measures:
Health state/QoL
Resources saved further down line
Productivity gain
Savings to patient and family
NHS decision making may only consider what perspective?
Health service implications
CMA =
Cost-minimisation analysis
What does a cost minimisation analysis assume?
Health effects are equal
Choice in a CMA is the treatment with
the lowest cost
In a CEA effects are measured in terms of
the most appropriate uni-dimensional nautral unit
is a CEA uni-dimensional or multi-dimensional?
Uni-dimensional
Benefits of CEA
Straightforward to carry out
Easy to interpret
Cons of CEA
One unit - may have a range of outcomes
Cannot compare alternatives which don’t have same unit
ICER =
Incremental cost-effectiveness ratio
Calculation for ICER
(c of intervention - c of control) / (mean effect of intervention - mean effect of control)
ICER will give you
Cost per unit outcome
Decision rules when using CEA
- Reject any alternatives that are dominated by others
- If not dominated, chose lowest ICER if below ceiling ratio
What does it mean when an alternative is ‘dominated’ by another?
Greater cost with no greater benefits.
Lower benefits at no smaller cost
Ceiling ratio =
Level of ICER which any alternative must meet if it is regarded as cost effective
NICE ceiling ratio =
20,000 per QALY saved
In CUA effects are (unidimensional/multidimensional)
Multi dimensional
CUA is a special care of what
CEA
CUA allows comparison of interventions that
would be measured using different clinical outcomes
CUA allows what to be allocated across clinical areas?
Global budget
Disadvantages of QALY league table:
Assumations underlying ratios not considered
Equity: people at bottom of list won’t get anything?
Is QALY the end goal?
The most comprehensive form of evaluation is the
Cost benefit analysis
Why is CBA more comprehensive?
Takes a societal perspective.
All costs and outcomes included
Why are CBAs controversial?
Monetary values to health outcomes - how do we do this?
Preferred economic evaluation in the UK
Cost utility analysis
Food posioning cases should be notified to
Public health England
Bacterial causes of food posioning:
Campylobacter
Salmonella
E.coli
Most common viral cause of food posioning:
Norovirus
Ex of fungal cause of food poisioning
Aspergillus
Ex of protozoal cause of food poisioning
Cryptosporidia
Chemicals that can cause food poisioning:
Heavy metals
Pesticides
Hercicides
Most common reported cause of food poisioning
Campylobacter
Most common/underreported source of FP
Norovirus
Salmonella is what type of bacteria
Gr -
S.typhi and S.paratyphi cause
Enteric fever
S.enteritidis causes
Enterocolitis
If food poisioning comes on very quickly it is likely to be
S.aureus
S.aureus food poisiong is due to a
Toxin
Cryptosporidium is not killed by
Chlorine
S.aureus is not killed by
Heating food
EPEC
Enteropathogenic E.coli
EPEC causes
Infantile diarrhoea
EAEC
Enteroagregative E.coli
EAEC causes
travellers diarrhoea
ETEC
Enterotoxic e.coli
EIEC
Enteroinvasive e.coli
EHEC
Enterohaemorrhagic E.coli
Ex of an EHEC
E.coli O157 H7
E.coli O157 H7 can cause
Gastroenteritis
Hemolytic uremia
Haemorrhagic colitis
Genome of Norovirus
RNA
Outbreaks of norovirus are common in
Semi-closed envirnoments
Incubation period of norovirus
24-48 hrs
Name 2 campylobacter species:
C.coli
C.jejuni
Why investigate food poisioning outbreaks?
Level of morbidity and mortality - Vulnerable groups (elderly and children), unpleasant, people do die Potentially can get very big outbreaks Common but changing problem Public concern with political implications We can do something about it We all need to eat and shouldn’t have to worry about what we eat
What act allows exclusions from work of people that pose an increased risk of GI infection spread?
Public health act
Ex of people protected by public health act
- Care workers
- Food handlers
- children in nurdery
Offences under the food safety act (1990)
- Sale of food that have been rendered injourous to health
- Sale of food not of the nature or substance or qulaity demanded by the purchaser
- Display of food for sale which falsely describes food
HACCP
Hazard analysis critical control point
GMP
Good manufacturing practice
HACCP is cmpulsory within
Good manufacturing procress
