Week 2 Flashcards
What is screening
Screening is a process of identifying apparently healthy people who may be at increased risk of a disease or condition. They can then be offered information, further tests and appropriate treatment to reduced their risk and/or any complications arising from the disease or condition.
Screening leads to early detection of: disease, pre-cursor for disease, susceptibility to disease
Screening can be done by:
Questionnaire (e.g. Geriatric Depression scale)
Examination (e.g. BP measurement)
Lab test (e.g Pap smear)
Imaging (e.g. mammography)
Result of applying a screening test
Disease +:
Test + = true positives
Test - = false negatives
Disease -:
Test + = false positives
Test - = true negatives
Important test characteristic:
- sensitivity: Rate of TPs - the proportion of diseased people identified as diseased
- specificity: rate of TNs- the proportion of healthy people identified as healthy
Sensitivity
How good the test is at picking up the disease
What is the effect of a highly sensitive test on false negatives. Fewer false negatives
a highly sensitive test more useful when the result is negative?
Sensitivity= true positives/ (true positives + false negatives)
Specificity
How good the test is at correctly excluding people without the condition
What is the effect of a highly specific test on false positives. Fewer false positives
a highly specific test more useful if result is positive
Specificity= true negatives/ (false positives+ true negatives)
High specificity and high sensitivity
High specificity important for screening where the consequences of misclassifying someone falsely as diseased are serious. Eg TOP for Down’s syndrome
High sensitivity important for screening where the consequences of missing disease are serious eg transfusion with HIV +ve blood
Effect of screening on individual
Sensitivity and specificity tells us only how good the test is at picking up or excluding disease
However, when we have the best possible test:
- if you test positive, how likely is it that you really have the disease
- if you test negative how likely is it that you really dont have the disease
For these questions, we need to know the predictive values
Predictive values
Positive predictive value (PPV)- if you test positive how likely is it that you really have the disease
PPV= true positive/ (true positive + false positive)
Negative predictive value NPV- if you test negative how likely is it you dont have the disease
NPV= true negatives / ( false negatives+ true negatives )
Prevalence of disease
Prevalence= (true positives + false negatives)/ (true positives+ false positives + false negatives + true negatives)
Who benefits from screening
Every outcomes has set of risks
The benefits must outweigh the harm caused by a screening programme
True positives= labelling
False negatives= false reassurance, disregard symptoms, delayed intervention
False positives= costs of further tests, risks of diagnostic testing, anxiety, fear of future screening
True negatives= costs and risks of screening programme
Screening in the UK
National screening committee:
- advises ministers- all aspects screening policy
-latest research evidence, multi- disciplinary expert groups, patient and service users
- Assess proposed new screening programmes against criteria to ensure they do more good than harm at reasonable cost
Natural history of disease
Condition worth screening only if we understand natural history
To make it worthwhile we need:
1- pre clinical detectable period
2- test that can be applied
3- treatment that will alter outcome
Criteria used by the NSC
The condition:
- important, has latent phase, natural history understood, primary prevention implemented
The test:
-suitable (simple, safe,precise, valid, acceptable), agreed suitable cut offs, agreed policy for test +ve
The intervention:
- effective treatment, policy on who to treat, adequate facilities
The screening programme:
- RCT evidence of effectiveness, info understandable by those screened, clinically, socially and ethically acceptable, benefits vs harms, value for money
Implementation of programme:
- clinical management and patient outcomes should be optimised, all other options considered, plan for monitoring programme, adequate staffing and facilities
Evaluation of screening programmes
If compare outcomes (eg survival times) in patients identified by screening to those identified clinically biases can occur:
-volunteer bias
-lead time bias
- length bias
Volunteer bias
Decision to attend screening is general influenced by an individuals health awareness
- do more ‘healthy’ people attend screening programmes
- is lower mortality rate from those who attend screening due to the screening programme or the population who attend screening
- when evaluating screening programmes its important to consider how patients are recruited
Volunteer bias/detection bias
Screened may differ from non screened (usually Lower risk)
Most important where coverage is low
Lead time bias
Time by which diagnosis is advanced because of screening-> apparent increase survival
(I.e the time between disease detection through screening and the disease detection by diagnosis without screening)
Length time bias
Those with long pre clinical phase more likely to be detected by screening and usually have better prognosis (less aggressive disease)
Slowly progressive disease- over represented in “screened cohort”
Rapidly progressive disease- under represented in screening
What is palliative care
About looking after people with incurable illnesses, relieving their suffering and supporting them through difficult times
Palliative- to cloak
Approach that improves the quality of life of patients and their families facing the problem associated with life threatening illness, through the prevention and relied of suffering by means of early identification and impeccable assessment and treatment of pain and other problems physical, psychosocial and spiritual
Palliative care
Provides relief from pain and other distressing symptoms
Affirms life and regards dying as a normal process
Intends neither to hasten or postpone death
Integrates the pyschological and spiritual aspects of patient care
Offers a support system to help patients live as actively as possible until death
Offers a support system to help the family cope during the patients illness and in their own bereavement
Uses a team approach to address the needs of patients and their families including bereavement counselling if indicated
Will enhance quality of life and may also positively influence the course of illness
Is applicable early in the course of illness, in conjunction with other therapies that are intended to prolong life such as chemotherapy or radiation therapy and includes those investigations needed to better understand and manage distressing clinical complications
End of life care
Enables the supportive and palliative care needs of both patient and family to be identified and met throughout the last phase of life and into bereavement
“ end of life care offers treatment and support for people who are near the end of their life. It usually starts to be offered to those who are though to be in the last year of their life. The aim is to help someone be as comfortable as possible in the time they have left, as well as making sure that practical things such as wills or wishes are sorted out’”
Supportive care
“The prevention and management of the adverse effects of cancer and its treatment. This includes management of physical and psychological symptoms and side effects across the continuum of the cancer experience from diagnosis through treatment to post-treatment care. Enhancing rehabilitation, secondary cancer prevention, survivorship and end of life care are integral to supportive care”
Total pain
Palliative care emphasises that these 4 areas of need are important and that problems in one area affect problems in other areas
- emotional/ psychological problems such as anxiety and depression can worsen many symptoms eg pain and breathlessness
-physical problems can worsen psychological ones eg pain can lead to depression
-social problems eg lack of income or loss of carers affects physical symptoms
-spiritual issues affect psychological well-being
Quality of death world ranking
According to the Worldwide palliative care alliance while more than 100m people would benefit from hospice and palliative care annually (including family and carers who need help and assistance in caring) less than 8% of those in need access it
Palliative care: health and social care integration
Patient
GP
Hospice
Hospital
Bereavement service
Department of work and pensions
Social services
Community nursing
End of life care policy
NHS EOL strategy 2008
NHS EOL Care programme DoH 2006 strategy to offer choice at EOL and provide training for healthcare staff to help care for people at the end of their lives
End of life care strategy DH 2008
The strategy:
- covers all conditions
-covers all care settings (eg home, hospital, hospice, care home, community hospital, prison etc)
-has been developed within the current legal framework
AIMS:
-to bring about a step change in quality of care for people approaching end of life
-to enhance choice at the end of life
-to deliver the governments manifesto commitment to double investment in palliative care
Do policies always get it right? The case of the Liverpool care pathway
July 2013 review of LCP for dying patients recommendations include:
-phasing out LCP and replacing it with an individual end of life care plan
- a general principle that a patient should only be placed on the LCP or a similar approach by a senior responsible clinician in consultation with the healthcare team
-unless there’s a very good reason, a decision to withdraw or not to start a life prolonging treatment should not be taken during any ‘out of hours’ period
-an urgent call for the nursing and midwifery council to issues guidance on end of life care
-An end to incentive payments for use of LCP and similar approaches
-A new system wide approach to improving the quality of care for the dying
Ambitions for palliative and end of life care
Each person is seen as an individual
Each person gets fair access to care
Maximising comfort and wellbeing
Care is coordinated
All staff are prepared to care
Each community is prepared to help
Predicting death
3 triggers that suggest a patient is nearing the end of their life:
-the surprise question “would you be surprised if this patient were to die soon”
-general indicators of decline-deterioration, increasing need or choice for no further active care
- specific clinical indicators related to certain conditions
Advance care planning discussions
What you do want to happen- AS statement of wishes and preferences
What you do not want to happen- ADRT-advance decisions to refuse treatment
Who will speak for you- Proxy or LPOA-lasting power of attorney
In line with the UK mental capacity act
What is health
WHO 1948:
“ a state of complete physical, mental and social wellbeing, not merely the absence of disease or infirmity”
“Health is a positive concept emphasising social and personal resources as well as physical capacities”
The determinants of health 1992 Dahlgren and Whitehead
Age, sex and hereditary factors
Individual lifestyle factors
Social and community networks
Agriculture and food production, education, work environment, living and working conditions, unemployment, water and sanitation, health care services, housing
General socioeconomic, cultural and environmental conditions
Delivering healthcare
Not just treating disease/ill health
Address conditions required for health
Health systems:
- who definition: “ all organisations, people and actions whose primary intent is to promote, restore and maintain health”
Not just NHS
Key principles of a comprehensive health system
Continually improves health status
Defends against health status
Protects against financial consequences of ill health
Equitable access
People centred care
Assists people to participate in healthcare decisions
Public health
“The science and art of preventing disease, prolonging life and promoting health through the organised efforts of society”
Aims to improve population health:
-health improvement eg wider determinants, lifestyles
- health service improvement eg clinical effectiveness, service planning
-health protection eg infectious diseases, environmental hazards
Individual and population healthcare
Individual healthcare:
-Individual health needs
-healthcare delivered to individual
-focus on individual patient rights
-doctors advocate for individual
Population healthcare:
- population health needs
-healthcare delivered to population
-focus on equity/ social justice
-doctors advocate for communities/patient groups
The healthcare continuum
Primary prevention: promoting and maintaining good health
Secondary prevention: early detection and treatment of causes of ill health
Tertiary prevention: optimal management of established conditions
End of life care: support for people approaching death
Patterns of ill health
Increased prevalence of chronic illness:
-changing risk factors (increase obesity decrease smoking)
-reduced mortality of life threatening conditions
Healthcare supply and demand
Supply: technological advances- drugs/procedures/diagnostic techniques
Demand: increased expectations - choice, convenience, personalisation
Responding to changing needs
Traditional health service models:
- disease based approaches
-compartmentalised:
— health care vs social care
— physical vs mental health conditions
- gaps in healthcare:
— older adults
—people with long term physical/mental health conditions
Integrated care model
Organise delivery of health and social care from a patients/community’s perspective
Integration across:
- health and social care
-primary, community, secondary, tertiary care
-prevention and treatment
-population and individual approaches
-professional and patient perspectives
Key features of healthy systems following devolution
Choice and competition model:England
-patients are informed consumers
-performance affects a providers market share
Scotland:
-focus on outcomes and performance management
Wales and Northern Ireland:
-trust and altruism model- intrinsic motivation of healthcare professionals, performance does not need to be managed
Private healthcare
In England there’s emphasis on:
-developing patient choice
-provider competition
NHS commissioners in England encouraged to contract with private sector to deliver publicly funded health care
-not the case in other Uk nations
Classification of prevention
Primordial: prevent disease by focusing on underlying social conditions that promote disease across the population
- social determinants and commercial determinants of health
Primary: prevent disease through health promotion activities aimed at healthy individuals
Secondary: reduce impact of disease through early disease detection, in healthy appearing individuals with sub clinical forms of the disease
Tertiary: reduce impact of disease (once established) in symptomatic patients
Quaternary: individuals from medical interventions that are likely to cause more harm than good
Tertiary prevention
Targets patients with established (chronic) disease
-intervention begins after acute disease process has run its course
-focussed on a limited number of patients
Focus is to improve function and prevent further disability and complications (limit the impact of the disease)
Lack of clear boundaries: on going process (long term interventions), no clear end points, in most areas there is limited evidence and poor consensus
Tertiary prevention strategies
Typically complex interventions
Multifaceted interventions comprised of components at multiple levels that are designed to work together
Possible strategies include:
- medical treatments
-rehabilitation
-patient education and self management
Strategies:
- rehabilitation programmes
- chronic condition management
Input and delivery of tertiary care
Input: multidisciplinary:
-dieticians
-doctors
-occupational therapist
-pharmacists
-physiotherapists
-psychologists
-speech and language therapists
Delivery:
-routine reviews, self management plans, patient/community support groups
Tobacco control measures
Public awareness campaigns: mass media, targeted education, regulation of advertising, bans on tobacco ads and sponsorship
Packaging and labelling: prominent health warnings
Tobacco duty and tax: increasing taxes
Enforcement
Access restrictions: age of sale, ban open display in stores
Protecting against second hand smoke: bans in public places
Smoking cessation services
NHS long term plan 2019
Lung cancer screening June 2023
What factors influence screening policy
Evidence= Uk NSC provides advice based on evidence
-evidence can be interpreted in different ways-hence different policies on screening internationally
Policy also considers:
-public opinion (eg celebrities, lobby groups)
-organisational support/credibility (eg influential bodies support)
-values (saving a life vs many having harms from false positives)
-commercial influences ( eg those promoting use of a test)
-political priorities/agenda (alignment with political goals)
