Public Health 2 Flashcards
Epidemiology
Study of…
- Frequency
- Distribution
- Determinants
…of disease and health
…in populations
… in order to prevent and control disease
Incidence
New cases in a set time period
Prevalence
Existing cases at a given point in time
Person time
Measure of time at risk
From entry to study to…
- Disease onset
- Loss to follow-up
- End of study
Used to calculate incidence rate
Person time is the denominator
Absolute risk
ACTUAL numbers
E.g. 50 deaths per 1000
Relative risk
Risk in one group relative to another
Ratio of risk of disease in exposed to risk of disease in unexposed
Incidence in exposed / incidence in unexposed
RR = 1 = No difference
RR > 1 = Intervention increases risk of outcome
RR < 1 = Intervention decreases risk of outcome
Attributable risk
Rate of disease in the exposed that can be attributed to the exposure
(Incidence in exposed - incidence in unexposed)
ABSOLUTE RISK
Relative risk reduction
RRR
Reduction in rate of outcome in the intervention group relative to control group
Absolute risk reduction
ARR
Absolute difference in the rates of events between the two groups
Gives an indication of baseline risk and intervention effect
Number needed to treat
NNT
Number of patients needed to treat to prevent ONE bad outcome
1 / absolute risk reduction
Reasons for association between exposure and outcome
Bias Chance Confounding Reverse causality True causal association
Bias
Systematic deviation from the true estimation of association between exposure and outcome
Systematic error which leads to a distortion of the true underlying association
Main groups of bias
Selection bias
Information bias
Selection bias
Systematic error
Selection of study participants
Allocation of participants to different groups
Information bias
Systematic error
Measurement or classification of exposure or outcome
Sources of information bias
Observer bias
Recall bias
Instrument
Confounding
A factor that is associated with the exposure in question
Independently influences the outcome
Association and causation considerations
Bias
Chance
Confounding
Criteria for causality
Reverse causality
Association between exposure and outcome
Could be due to outcome causing exposure
Causality criteria
Bradford-Hill
- Strength of association - Magnitude of RR
- Dose-response - Higher exposure = Higher risk
- Consistency - Similar results from different researchers and various study designs
- Temporality - Does exposure precede outcome
- Reversibility - Removal of exposure reduces risk of disease
- Biological plausibility - Biological mechanisms explaining the link
- Coherence - Logical consistency with other information
- Analogy - Similarity with other established cause-effect relationships
- Specificity - Relationship specific to outcome of interest
Different types of health behaviours
Health behaviour - Behaviour aimed at preventing disease (eating healthy)
Illness behaviour - Behaviour aimed at seeking remedy (going to the doctor)
Sick role behaviour - Activity aimed at getting well (taking medications)
Theory of planned behaviour
Best predictor of behaviour is intention
e.g. I intent to give up smoking
Intention in the theory of planned behaviour
Persons attitude towards the behaviour
Perceived social pressure to undertake the behaviour
Persons appraisal of their ability to perform the behaviour
Perceived behavioural control
Theory of planned behaviour
Criticisms
Lack of temporal element
Lack of direction or causality
Stage models of health behaviour
5 stages of change
- Precontemplation
- Contemplation
- Preparation
- Action
- Maintenance
Motivational interviewing
Counselling approach
Initiating behaviour change by resolving ambivalence
Nudge theory
Nudge the environment to make the best option the easiest
E.g. opt-out schemes
Factors to consider in behavioural change
Impact of personality traits on health behaviour
Impact of past behaviour
Assessment of risk perception
Social norms
Automatic influences on health behaviour
Predictors of maintenance of health
Transition points leading to behaviour change
Positive or negative
Leaving school Entering the workforce Becoming a parent Becoming unemployed Retirement Bereavement
NCSCT
National Centre of Smoking Cessation and Training
Social enterprise
Support the delivery of effective evidence-based tobacco control programmes
Smoking cessation interventions
Provided by local stop smoking services
What does the NCSCT do
Delivers training and assessment programmes
Provides support services for local and national providers
Conducts research into behavioural support for smoking cessation
Why notify PHE about communicable disease
They notify health protection agency
Health protection agency can take urgent control measures
Duty of medical practitioners
When do medical practitioners have to notify
Notifiable diseases
INFECTION which could present significant harm to human health
CONTAMINATION which could present significant harm to human health
When do diagnostic laboratory operators have to notify
Causative agents found in human samples
Must provide in writing within 7 days
Duty to provide information to HPA
HPA may require requesting clinician to provide supplementary information
Must provide in writing within 3 days of HPA request
Local authority powers
Schools
- Keep children away from school
- Schools must provide list of attendees
Requests for co-operation - Serve notice
- Asking people to do (or not do) something
- For prevention, protection, control or provision of public health response
- Response to incidence, contamination, or spread of infection
- Which presents or could present significant harm to health
MAY OFFER COMPENSATION
Magistrate order requirements - People
Medical examination
Disinfection or decontamination
Removal and/or detention in isolation or quarantine
Wear protective clothing
Restrict movements
Prohibition from working or trading
Provide information
Attend training sessions
Monitor
Magistrate order requirements - Things
Seizure or retention
Isolation or quarantine
Disinfection or decontamination
Destruction
Magistrate order requirements - Premises
Closure
Detention of conveyances or movable structures
Disinfection or decontamination
Destruction
Role of consultant in communicable disease control
Surveillance - Monitor communicable disease
Prevention - E.g. immunisation programmes
Control - Procedure when routine cases and outbreaks occur
Managing outbreaks of communicable disease
- Clarify the problem - Make the diagnosis
- Decide if this is an outbreak (2 or more related cases of a communicable disease)
- Get help - Microbiologists, health visitors, consultants, etc.
- Call an outbreak meeting
- Identify the cause
- Initiate control measures
Models of transmission for communicable disease
- Foodborne
- Faeco-oral
- Respiratory
- Physical contact
- Animals
Maslow’s hierarchy of needs
- Physiological
- Safety
- Love/belonging
- Esteem
- Self actualisation
Relationship breakdown leading to homelessness
Mental illness
Domestic abuse
Disputes with parents
Bereavement
Problems facing the homeless
Infectious disease
Sexual health - Contraception unavailable
Poor nutrition
Addiction and substance misuse
Injuries following violence and rape
Mental illness
Feet and teeth problems
Respiratory
Travellers and gypsies
Barriers to healthcare
GPs won’t visit sites
Constantly moving
Illiteracy
Communication difficulties
Mistrust of professionals
Homeless people
Barriers to healthcare
Difficulties with access - Opening times and appointment procedure
Perceived (actual) discrimination
Lack of integration between primary care services and other agencies
Unsure of where to find help
Asylum seeker
Has made an application for refugee status
Refugee
Person granted asylum and refugee status
5 years
Then reapply
Humanitarian protection
Failed to demonstrate claim for asylum
Face serious threat to life if returned
3 years
Then reapply
Asylum seekers lives
No choice dispersal
Not allowed to work
Vouchers - 70% of income support sum
NASS support package
Full access to NHS
Asylum seekers - Physical health problems
Common illness
No previous screening or immunisations
Untreated chronic/congenital disease
Illness specific to country of origin
Injuries from war or travelling
Communicable disease
Malnutrition
Sexual abuse/exploitation
Asylum seekers - Mental health problems
PTSD
Sleep disturbance
Depression
Self-harm
Psychosis
