Block 9 Flashcards
What factors feed in to an evidence-based decision? (4)
- evidence from research
- patient preferences
- clinical expertise
- available resources
Why do we need evidence based medicine?
- increasing medical knowledge
- limited time for clinicians to read
- inadequacy of “traditional” sources of information (e.g. textbooks are out of date as soon as they are published)
- disparity between:
(1) diagnostic skills and clinical judgement - which increase over time
(2) up-to-date knowledge and clinical performance - which tend to decrease over time
What is evidence-based medicine?
The process of identifying and using the most up-to-date and relevant evidence to inform decisions for individual patient problems
Outline the 5-step process of evidence-based medicine:
1) Converting the need for information into an answerable question (PICO)
2) Identifying the best evidence to answer that question
3) Critically appraising the evidence for its validity, impact and applicability
4) Integrating the critical appraisal with clinical expertise and the patient’s unique circumstances
5) Evaluating our effectiveness and efficiency in carrying out in steps 1-4, and seeking ways to improve them
What are the four essential components of a foreground question?
P - Patient / Problem
I - Intervention
C - Comparison Intervention (if relevant)
O - Clinical Outcome(s)
E.g. In younger women with breast cancer, is mastectomy with chemotherapy more effective than mastectomy alone, in reducing the risk of cancer recurrence?
What is the aim of a background question?
Seek general knowledge about a disorder
What is the aim of a foreground question?
Seek specific knowledge about managing patients with a disorder
What are the two essential components of a background question?
1) A question root: who, what, where, when…
2) A disorder or an aspect of a disorder
e.g. What causes breast cancer?
How does need for background and foreground questions vary over time?
- depends on expertise
- more background questions when less experienced with the condition
- more foreground questions when more experienced with the condition
What are the 5 components of the chain of infection?
- infectious agent
- reservoir/environment
- mode of transmission
- portal of entry
- host
What characteristics of the infectious agent influence who gets infected, how and why?
- ability to reproduce
- survival
- ability to spread
- infectivity
- pathogenicity
Describe modes of infection transmission:
Respiratory:
- droplet
- airborne
- aerosolisation of water
Ingestion:
- consumption
- hand-to-mouth (person to person, or environment or person)
Blood borne
Sexual
What characteristics of potential hosts influence who gets infected, how and why?
- chronic illness
- nutrition
- age (extremes)
- immunity (lack of)
- lifestyle factors (drugs, alcohol, sex, occupation, deprivation, physical activity etc)
What is the motivation for global health?
- Increased awareness of global health disparities
- Enthusiasm to make a difference across borders
What is the 10/90 gap?
10% of global healthcare resources are allocated to 90% of the global population
What are the key words associated with the definition of global health?
- health of the global population
- equity
- interdependence
- transnational
- emphasis on wider determinants of health
- interdisciplinary / cross-sector working
- prevention AND care
Give 5 global issues that affect health globally:
- global warming
- development, poverty, and inequality
- food and water security
- wars and security threats
- migration
What are the major functions of global health?
- provide health-related public goods (e.g. research, guidelines)
- manage cross-national externalities through epidemiological surveillance, information sharing and coordination
- mobilise global solidarity for populations facing deprivation and disasters
- convene stakeholders to reach consensus on key issues (setting priorities, negotiating rules, facilitating mutual accountability, advocating for health in other policy-making arenas)
Why do we have innate immunity?
- prevent pathogen establishment
- limit pathogen multiplication
- provide protection from early death during expansion of acquired immune response
- broad specificity
- helps direct and shape the acquired immune response
How might pathogens avoid complement activation?
- surface structure
- regulatory proteins
How might pathogens avoid phagocytosis?
- capsules
- anti-phagocytic ‘toxins’
How might pathogens evade host defences?
- avoid complement activation
- avoid phagocytosis
- inhibit host cell signalling pathways
- resist or evade phagocyte killing mechanisms
What is the goal of active immunisation?
Induce a state of immunological readiness such that a first infection with a given pathogen is recognised as though it were the second infection
What is the goal of passive immunisation?
Transfer preformed immunological mediators into a normal individual to generate a state of enhance immunity
Give 3 types of passive vaccination:
- specific antibody transfer
- transfer of normal serum gammaglobulins
- maternal antibodies (placental IgG, colostral IgA)
What are the different types of active vaccines?
Live:
- natural attenuated (related strain or species e.g. smallpox and cowpox)
- artificially attenuated (e.g. MMR)
Non-living:
- killed whole organisms (e.g. typhoid)
- antigenic components of the organism (e.g. HepB)
- DNA from the organism (none licensed yet)
Why was the eradication of smallpox possible? (4)
- exclusive to humans
- no hidden carriers
- single serotype
- vaccination 100% successful
What is bad news?
Any news that drastically and negatively alters the patient’s view of their future
Give examples of psychosocial context that might mean something is bad news for one person but not for another:
- Social life, e.g. teen diagnosed T1D
- Employment, e.g. surgeon who develops Parkinson’s tremor
- Finance, self-employed and needing time off work for treatment
- Social, e.g. mother with acute pain who is alone looking after young children
Why might breaking bad news be difficult?
- institutionalised beliefs
- personality types
- personal experience
- gender
- culture
- religion
- relatives of the patient
Why might clinicians avoid giving bad news?
- uncertainty of patient expectation
- fear of destroying hope
- fear of inadequacy
- not feeling prepared to manage the patient’s response
- embarrassment due to having previously given too optimistic a view to the patient