Public health Flashcards
Define public health
The science and art of preventing disease prolonging life and improving health through organised efforts of society
Define equity
Giving people what they need to achieve equal outcomes
Define equality
Giving everyone the same rights, opportunities and resources
Define horizontal equity
Equal treatments for people with equal healthcare needs
E.g. same tx used for pneumonia in different patients with the same severity of pneumonia
Define vertical equity
Unequal treatments for unequal health care needs
E.g. different treatments used in less severe vs more severe pneumonias
What is the inverse care law?
Availability of health care tends to vary inversely with its need
What are determinants of health?
Wide range of factors that influence a person’s health
Name some determinants for health
PROGRESS
Place of residence
Race
Occupation
Gender
Religion
Education
Socioeconomic
Social capital
What are the 3 domains of public health?
Health improvement
Health protection
Improving services/health care
What is meant by ‘health improvement’
Interventions aimed at promoting overall health-education, housing, employment
What is meant by ‘health protection’
Measures to control infectious disease and environment hazards-vaccination, radiation, emergency response
What is meant by ‘improving services’/health care
Organisation and delivery of safe, high quality services-clinical effectiveness, audit, etc
Name some frameworks used to assess the quality of healthcare
Maxwell’s dimensions of quality of healthcare
Structure, process, outcome
Describe Maxwell’s dimensions of quality of healthcare
3As and 3 Es
Acceptability
Accessibility
Appropriateness
Effectiveness
Efficiency
Equity
Give an example of a structure in the ‘structure, process, outcome’ framework
Number of hospitals, number of doctors etc
Give an example of a process in the ‘structure, process, outcome’ framework
Number of patients seen, number of tests done, number of surgeries done
Give an example of an outcome in the ‘structure, process, outcome’ framework
Number of deaths
What is a health needs assessment?
A systematic approach for reviewing health issues affecting a population in order to enable agreed priorities and resource allocation to improve health and reduce inequalities
What are the 3 main things taken into account in a health needs assessment?
Need: ability to benefit from an intervention
Demand: what people ask for
Supply: what is provided
Give an example of something that is supplied and demanded but not needed
Abx for a viral infection
Give an example of something that is demanded and needed but not supplied
Large waiting lists for procedures
Give an example of something that is needed and supplied but not demanded
Routine vaccinations
What are the types of needs in a health needs assessment
Felt need
Expressed need
Normative need
Comparative need
What is a ‘felt’ need? Give an example
Individual perceptions of variation form normal health-‘I feel unwell’, ‘My knee hurts’
What is an ‘expressed’ need? Give an example
Individual seeks help to overcome variation in normal health-goes to dr
E.g. going to the dentist for a toothache
What is a ‘normative’ need? Give an example
Professional defines intervention for the expressed need
E.g. Vaccinations, decision by surgeon that a patient needs an operation
What is a ‘comparative’ need? Give an example
Needs identified by comparing services received by one group vs another
E.g Rural village may identify need for a school if the neighbouring village has one
What are the 3 perspective of a health needs assessment?
Epidemiological
Comparative
Corporate
What does an epidemiological perspective of a health needs assessment look at?
1)Size of population-incidence/prevalence
2)Service available-prevention/treatment/care
3)Evidence base-(cost)effectiveness
What sources might be used when carrying out a epidemiological health needs assessment?
Disease registry
Admissions
GP databases
Name some advantages of using an epidemiological perspective to a health needs assessment
Uses existing data
Provides data on disease incidence/mortality/morbidity
Name some disadvantages of using an epidemiological perspective for a health needs assessment
Quality of data is variable
Data collected may not be data required
Does not consider felt needs/opinions of patients
Give an example of an epidemiological perspective
Looking at new incidence of measles in a certain town through GP records
What is involved in the comparative perspective of a health needs assessment?
Compares services/outcomes received by a population with others
Could compare different areas of patients of different ages etc
What does a comparative perspective of a health needs assessment look at?
Health status
Service provision
Outcomes
Name some advantages of using a comparative assessment for a health needs assessment
Quick and cheap if data available
Shows if services are better/worse than compared group
Name some disadvantages of using a comparative perspective for a health needs assessment
Can be difficult to find comparable population
Data may not be available/high quality
Give an example of a comparative perspective
Compare rated of CVD between town A and B
What is involved in a corporate perspective for a health needs assessment
Asks local populations what their health needs are
Uses focal groups, interview, public meetings
Wide variety of stakeholders
Name some advantages of using a corporate perspective for a health needs assessment
Based on felt and expressed needs of population
Recognises detailed knowledge and experience f those working with the population
Takes into account a wide range of views
Name some disadvantages of using a corporate perspective for a health needs assessment
Can be difficult to distinguish needs from demand
Groups may have vested interest
May have political agendas
Give an example of using a corporate perspective for a health needs assessment
Arrange focus group with patient from a GP surgery to discuss their views
Name some different approaches to resource allocation
Egalitarian: provide ALL care that is necessary and required for everyone(NHS)
Maximising: Act is evaluated solely in terms of its consequences(flu vaccine)
Libertarian: Each is responsible for their own health(private ehalthcare)
Name an advantage and disadvantage to an egalitarian approach to resource allocation
Good: equality
Bad: too expensive
Name an advantage and disadvantage to a maximising approach to resource allocation
Good: resources allocated to those most likely to benefit it
Bad: Those who don’t make the cut get nothing
Name an advantage and disadvantage to a libertarian approach to resource allocation
Good: promotes positive engagement
Bad: Most diseases are not self inflicted
What are the 3 kinds of prevention
Primary
Secondary
Tertiary
What is secondary prevention
Early identification of the disease to alter the disease course e.g screening, aspirin after a MI
What is primary prevention?
Preventing the disease from occurring in the first place
E.g. vaccination
What is tertiary prevention?
Limit consequences of established disease
E.g. prevent worsening renal function in CKD
What is a population approach to prevention
Delivered to everyone to shift the risk factor distribution curve
E.g. dietary salt reductions through legislation
What is a high risk approach to prevention?
ID all individuals above a chosen cut off an treat them
E.g. screening people for high BP and treating them
What is meant by the prevention paradox?
Preventative measure that brings much benefit to the population often offers little impact to each participating individual
E.g. mass immunisation
What is the purpose of screening?
ID apparently well individuals who have or at risk of developing a particular disease so you can have a real impact on the outcome
Name some disadvantages to screening
Exposure of well individuals to distressing/harmful diagnostic tests
Detection and treatment of sub-clinical disease that wouldn’t cause a problem
Preventative intervention that may cause harm to the individual or population
What screening programmes are done for pregnant women in the UK
Infectious diseases(hep B, syphilis, HIV)
Sickle cell and thalassaemia screening
Fetal anomaly screening(Down’s, Edward’s, Patau’s)
What screening programmes are in place for newborn babies?
NIPE(heart, eyes, hips, testes)
Hearing screening programme
Blood spot(sickle cell, CF, congenital hypothyroidism)
What screening programmes are done for young people and adults in the UK?
AAA screening
Bowel cancer
Breast cancer
Cervical screening
Diabetic eye screening
What criteria is used to determine if screening should be done for a disease?
Wilson and Jungner criteria
Describe the Wilson Jungner criteria
In Exam Season NAP
Important disease
Effective tx available
Simple and safe
Natural hx of disease known
Acceptable to patients
Policy on who to treat
Define sensitivity
Proportion of those with disease who are correctly identified
(If you have the disease, what are the chances the test will pick it up?)
Define specificity
Proportion of people without disease who are currently excluded by screening test
(If you don’t have the disease, what are the chances the test will tell you you don’t)
Define positive predictive value
Proportion of people with a positive test result who actually have the disease
(SNIP-Sensitivity is positive)
Define negative predictive value
Proportion of people with a negative test result who do not have the disease
SPIN)Sensitivity is negative)
What are predictive values influenced by?
Underlying prevalence
How do you calculate sensitivity?
people with the disease+positive screening/everyone who has the disease
How do you calculate specificity?
People with negative result who don’t have disease/everyone who doesn’t have the disease
How do you calculate the positive predictive value?
people with positive result who have the disease/everyone with a positive result
How do you calculate the negative predictive value
Those with negative result who don’t have disease/everyone who receives a negative result
Name 2 biases associated with screening
Length time bias
Lead time bias
What is length time bias?
Screening is more likely to detect slow-growing disease that has a long phase without symptoms-> appear to be survival benefit to screening even when early detection doesn’t improve outcomes
What is lead time bias?
Patients diagnosed appear to live longer because they know the have the disease for longer-> awareness of disease makes it falsely seem like early diagnosed patients live longer
Describe the hierarchy oof evidence
Editorials and expert opinions
Case series and case reports
Case-control studies and cross sectional studies
Cohort studies
RCT
Systematic review and met-analysis
Describe the features of a case-control study
Retrospective, observational study looking at the cause of disease
Compares similar participant with disease to controls without
‘Case’ and ‘control’: look for exposure in both cases and control group and see what the effects are
Name some advantages of a case-control study
Good for rare outcomes
Quicker than cohort or intervention studies(outcome already happened)
Can investigate multiple exposures
Name some disadvantages of a case-control study
Difficulties finding controls to match with case
Prone to selection and information bias
Describe the features of a cross-sectional study
Retrospective observational collects data from a population at a specific point in time ‘snapshot’
Prevalence of risk factors and disease itself
Name some advantages of a cross-sectional study
Relatively quick and cheap
Provide data on prevalence at single point in time
Good for surveillance and PH planning
Name some disadvantages of a cross-sectional study
Risk of reverse causality
Can’t measure incidence
Recall and response bias risk(may miss quick recovery)
Describe the features of a cohort study
Prospective longitudinal study looking at separate cohorts with different treatments/exposures and waiting to see if disease occurs
Name some advantages of a cohort study
Can follow up group with a rare exposure
Good for common and multiple outcomes-> establish disease risk and confounders
Less risk of selection and recall bias
Name some disadvantages of a cohort study
Takes a long time
People drop out
Need large sample size, expensive and time consuming
Describe the features of a randomised control trial
Prospective study, all participants randomly assigned exposure or control intervention
Name some advantages of a RCT
Low risk of bias and confounding factors
Can infer causality
Name some disadvantages of RCT
Time consuming, expensive
Drop outs
Inclusion criteria may exclude some populations
Describe the features of an ecological study
Looks at prevalence of disease over time(population data rather than individual)
Can show prevalence and association but not causation
What are ‘odds’ used for looking at?
Looking at binary outcomes: disease occurs or does not
How do you work out odds?
Probability of an event occurring/probability of an event not occuring
What is an odds ratio used for?
Compare the odds of an outcome occurring between two groups: usually the group with the exposure/treatment and a control group
How do you work out odds ratio?
Odds of an event(Condition A)/Odds of an event(condition B-control group)
What is an absolute risk?
Number of events(good or bad) in a treated(exposed) or control(non-exposed) group, divided by the total number of people in that group
Compared risk of health event between 2 groups
How do you calculate the absolute risk reduction?
Absolute risk of events in control group-absolute risk of events in the treatment group
How do you calculate relative risk?
Absolute risk(treatment)/absolute risk(control)
How do you calculate relative risk reduction?
1-relative risk
How do you calculate the number needed to treat?
1/absolute risk reduction
What is meant by numbers needed to treat?
Number of pts needed to treat for one to benefit
How do you calculate the number to harm?
1/(absolute risk in treatment group-absolute risk in control group
What does relative risk not take into account?
Baseline risk
Describe the to interpret relative risk and odds ratios
=1: no statistical difference between control and intervention
>1: control better
<1: intervention bettwe
How should you interpret confidence intervals?
95% statistically significant
Name some advantages of using an odds ratio
Very simple
Don’t need incidence
Binary outcome
Usually used in retrospective studies
Name a disadvantage of using an odds ratio
Can overestimate risk in rare disease
Name some features that might make yu use relative risk rather than odds ratio
Needs incidence of disease
Usually prospective, cross sectional, cohort and RCT
Able to examine and model a variable over time
Name some different types of bias
Measurement bias
Observer bias
Recall bias
Reporting bias
Selection bias
etc
What are the 4 types of information bias
Measurement bias
Observer bias
Recall bias
Reporting bias
What is measurement bias?
Different equipment measuring differently
What is observer bias
Observers expectations influence reporting
What is recall bias
Past events not recalled correctly
What is reporting bias?
People don’t tell the truth because od shame or judgement
What is selection bias?
Bias in recruiting for a study
Some may be lost to follow up
What is publication bias?
Trials with negative results less likely to be published
What criteria is used for assessing causality?
Bradford-Hill criteria
Describe the Bradford Hil criteroa
Strength
Temporality
Coherence
Consistency
Plausability
Analogy
Dose response
Reversibility
Specificity
What is meant by strength in the Bradford hill criteria
The stronger the association between exposure and outcome, the less likely the relationship is due to a different factor
High relative risk
What is meant by temporality in the bradford hill criteria
Most important
Exposure occurs before the outcome
Smoke before getting lung cancer
What is meant by dose-response?
More risk of outcome with more exposure
Heavier smokers have higher risk of lung cancer
What is reversibility with regards to the Bradford hill criteria
Removing the exposre decreases/eliminates risk
Stopping smoking reduces risk of lung cancer
What is consistency with regards to the Bradford hill criteria
Association is seen in different areas, different study designs, in different subjects-repeatability
What is plausability with regards to the Bradford hill criteria
Existence of reasonable biological mechanism for the cause and effect lends weight to the association
What is meant by coherence with regards to the Bradford hill criteria
Logical consistency with other information
What is meant by analogy with regards to the Bradford hill criteria
Similarity with other established cause effect relationships
What is meant by specificity with regards to the Bradford hill criteria
Relationship is specific to outcome of interest
What is a confounder?
Apparent association between an exposure and an outcome is actually the result of another factor
Name some causes of association
Bias
Confounding factors
Chance
Reverse causality
True association-confirmed by Bradford hill criteria
Define epidemiology
Study of frequency, determinants and distribution of diseases and health related states in populations in order to prevent and control disease
Define incidence
Number of new cases over a certain time period
Define prevalence
Number of people with a disease at a certain point in time
Define person time
Measure of time at risk for all patients n the study
(1000 patients studied for 2.5 years: 2500 person years)
What is the difference between incidence and prevalence?
Incidence: changes with time, new cases
Prevalence: number at a set time of existing cases
If 30000 students are with the UHS, 3600 are currently diagnosed with asthma. 1000 new cases diagnosed. Calculate the incidence over the past 10 years and the prevalence
Incidence:
1000 cases per 30000 people per 10 years
(1000/30000) x 100=3.3% per 10 years
Prevalence:
(3600/30000) x 100=12%
What are the 3 kinds of behaviors related to health?
Health behaviour-prevent disease-going to dr
Illness behaviour-seek remedy-going to the dr
Sick role behaviour-getting well-taking medication
According to Weinstein why do people practice health damaging behaviour
Inaccurate perceptions of risk and susceptibility-‘unrealistic optimism’
Name some things that influence the perceptions of risk
-Lack of personal experience with problem
-Belief that it is preventable by personal action
-Belief that if it hasn’t happened by now, it’s not likely to
-Belief that the problem is infrequent
What are transition points?
Points at which interventions are thought to be more effective
Name some transition points
Leaving school
Entering the workforce
Becoming a parent
Becoming unemployed
Retirement and bereavement
Name some models of behaviour change
Health belief model
Theory of planned behaviour
Stages of change/transtheoretical model
Social norms theory
Motivational interviewing
Describe the health belief model
Individuals will change their behaviour if they:
-Believe they are susceptible to the condition
-Believe in serious consequences
-Believe taking action reduces susceptibility
-Believe that the benefits of taking the action outweigh the costs
Name some disadvantages of the health belief model
Doesn’t account for social cues in change of behaviour
Doesn’t consider influence of emotions
Doesn’t differential between first time and repeat behaviour
E.g. alcohol
Describe the theory of planned behaviour
Best predictor of behaviour is ‘intention’
Main factors:
-Attitude
-Subjective norm
-Perceived behaviour control
-Behavioural intention
Name some advantages of the theory of planned behaviour mdoel
Takes into acocunt social influence
Useful for predicting intentions but not for actual behaviours
Describe the theory of planned behaviour using smoking as the example
-Attitude: I don’t think smoking is a good thing
-Subjective norm: most people who are important to me want me to give up smoking
-Perceived behavioural control: I believe I have the ability to give up smoking
Behavioral intention: I intend to give up smoking
Describe the stages of change(transtheoretical model)
Pre-contemplation(no intention)
Contemplation(no commitment but aware of problem)
Preparation
Action
Maintenance
Relapse
Name some advantages and disadvantages od the stages of change model
A: Acknowledges differing stages of readiness, allows relapse
D: People may skip changes, doesn’t take cultural views into account
Describe the features of addiction
Craving
Tolerance
Compulsive drug seeking behaviour
Withdrawal
What can you offer a newly presenting drug user?
Screening for blood borne viruses
Health check
Sexual health advice/contraception
Check vaccination history
Signposting to drug services
What are the principles of treating drug users
Reduce harm to user, family and friends
Improve health
Stabilise life
Reduce crime
What is positive and negative conditioning with regards to drug use
Positive conditioning: Addiction increases desire to use drug
Negative conditioning: People don’t quit due to unpleasant symptoms
What receptors does heroin act on?
Opiate receptors
Name the symptoms of heroin use
Euphoria
Miosis
Drowsiness
Name the negative sx of heroin use
Dependence
Bad withdrawals
Nausea
Itching
Sweating
Constipation
Respiratory depression
Name some medications used in opiate dtox
Methadone: used for transition-free, no theft, not injected
Naltrexone
Buprenorphine
How is cocaine/crack ingested?
Oral/snorting/IV
How does cocaine cause pleasurable sensation?
Blocks reuptake of serotonin-intense pleasure
How does cocaine cause negative symtpoms
Depletion at secretory neurones-> anxiety, panic, adrenaline secreiont-#> depression, panic, paranoia
Describe Maslow’s Hierarchy of needs
Bottom-top
-Physiological needs-food, water, rest(basic)
-Safety needs(basic)
-Belongingness and love needs(*psychological)
-Esteem needs-accomplishment(psychological)
-Self-actualization(self-fulfillment)
How is alchol use assessed?
CAGE questionnaire
AUDIT->15-refer for specialist support
Calculating units
How do you calculate the number of units?
Volume drunk(L) x % of alcohol= untis
What factors are used to assess the level of alcohol dependency
-Withdrawal sx
-Cravings
-Drinking despite consequences(physical/social/work life)
0Tolerance
Primacy-neglecting other activities
-loss of control
Narrowing of repertoire
Describe 2 medications that can be used to treat alcohol dependency
Disulfiram
Acamprosate
Describe the features of disulfram
Promotes abstinence-> alcohol intake causes severe reaction due to inhibition of acetaldehyde dehydrogenase
CI: IHD and psychosis
Describe the features of acamprosate
Reduces cravings
Weak antagonist of NMDA receptors
What is an asylum seeker?
Someone who is applying for refugee status
What is a refugee?
Someone who has been granted asylum status, usually for 5 years
Name some barriers for refugees accessing health
Reluctance of GPs to register them
illiteracy
Communicaiton
Lack of permanent site
Mistrust of professionals
What care to asylum seekers receive
Vouchers to live off
NASS support package
Access to NHS
Not allowed to work initially, no control over location
What happens for healthcare access if an asylum seekers claim is refused?
Can only access emergency NHS services-charged for anything else
Name some health problems for refugees
Injury/illness from war/traveling
Communicable disease
Lack of health screening and immunisation
Malnutrition
Untreated chronic disease
Mental illness
What is malnutrition?
Deficiencies, excess or imbalances in a person’s intake of energy and/or nutrients
What 3 groups are covered by malnutrition?
Undernutrition-stunting(low height), wasting(low weight for height), underweight(low weight for age), micronutrient
Overweight/obesity: + diet related noncommunicable diseases(heart disease, stroke, diabetes etc)
Micronutrient deficiencies-hidden hunger
What are the 4 dimensions of food insecurity
-Availability(affordability) of food
-Access-economic and physical
-Utilisation-opportunity to prepare food
-Stability of the 3 dimensions over time
Name some errors in practice
Sloth-not checking results/information for accuracy
Lack of skill
Communication breakdown-uncelar instructions and not listening to others
System failure-machine/equipment
Human factors-bravado, timidity
Judgement failure
Neglect
poor performance
Misconduct
Describe the classifications of error
Intention-failure of planned action to reach desired action
Action-task specific
Outcome-near miss or death
Context-interruptions, team factors
Name some strategies to reduce error in practise
Team training
Checklists
Simplification and standardisation of clinical practice
What are the 4 stages of negligence?
-Was there a duty of care?
-Was there a breach in that duty?
-Was the patient harmed?
-Was the harm due to the breach in care?
What is a never event?
Serious, largely preventable patient safety incidents, should not occur if the available preventative measures have been implemented
E.g cutting of the wrong leg
What tests can be used to check for negligence?
Bolam: would a group of reasonable doctors do the same?
Bolitho: Was the action taken reasonable?
What are the different approaches to dealing with negligence?
Person approach-hols one person acocuntable
Systems approach: ID errors in system
Name an advantage of the systems approach to negligence
Eliminates blame culture
Name 2 models for understanding accidents and improving safety?
Swiss cheese model-problems occur when multiple holes line up
Buckets model
Describe the buckets model
3 buckets:
-Self(fatigue, lack of knowledge/experience)
-Context(distractions, poor handover, no team support)
-Task(complexity, incomplete)
What is intervention at a population level?
Health promotion=enabling people to exert control over their health
-Awareness campaigns
Screenign and vaccination
What is intervention at the individual level?
-Patient centred approach-care responsive to individual needs
What is the duty of candour?
Every healthcare professional must be open and honest with patients when something that goes wrong with their treatment has the potential to cause harm or distress
Describe the rules for childhood consent
Never inform parents-encourage them to inform
<13yrs can’t consent-> social services
Describe the Fraser guidelines
Contraception for <16yrs
Does she understand the advice?
Has the dr encouraged her to tell her parents?
Will she have sex anyway?
Is the mental/physical health going to be affected if you don’t give it?
Best interests?
Describe the features of Gillick’s competence
-Does a child <16yrs ahve capacity to make own medical decisions
-Clinical judgement made by the dr-takes into account age, capacity, maturity
How should you report a notifiable disease?
Case details, NHS no, DOB, contact details to public health England
Report by writing within 3 days or telephone within 24 hours if urgent
Always report on clinical suspicion-don’t wait for lab confirmation
Name some features of a disease that make it a public health concern
High mortality
High morbitiy
Highly contagious
Expensive to treat
Effective intervetions
Name some notifiable disease
Encephalitis/meningitis
Food poisoning
Invasive Group A strep
Measles
Mumpls
Rubella
Scarlet fever
Smallpox
TB
Whooping cough
Emergency infectious disease, known chicken pox in healthcare worker, radiological/chemical hazard
What are the key points in communicable disease control
Surveillance
Prevention
Control
What is a cluster?
Group of cases that might be linked?
E.g. scabies in a care home
What is an epidemic?
More than expected incidence in a country
What is a pandemic?
> 1 country
What is an endemic?
Persistent levels of disease ocurrence
What is a hyper-endemic?
Persistently high level of disease occurence
Describe the swiss cheese model
Failed or absent defences against errors happening(latent failures)
Organisational influences-> unsafe supervision-?> preconditions for unsafe acts-> unsafe acts
