PH Flashcards
Causes of associations of outcome in a study
1) Bias
2) Chance
3) Confounding
4) Reverse causality
5) True association
What is a bias
Systematic error resulting in deviation from true effect
Types of bias
Selection bias (non-response by certain groups, loss to follow up etc)
Allocation bias (Groups with differing traits allocated to diff groups)
Information bias
- Measurement bias (diff equipment gives diff reading)
- Observation bias (observers expectations influence
- Recall bias (memory)
- Reporting bias (don’t report the truth)
Publication bias (negative results less likely to get published
Bradford Hill criteria (9 things to prove a relationship is causal)
Strength of association (high relative risk)
Consistently shown across studies
Temporality
Dose response
Reversibility
Biological plausibility
etc
Randomised control trial
2 Pros and 2 Cons
Low risk of bias and confounding + can show causality
Time consuming
Expensive
Case control:
What is it?
2 Pros + 2 Cons
Observational study comparing those with disease (case) to those without (control). Looks retrospectively at exposures.
Pro: Quick, good for rare diseases
Cons: difficult finding appropriate controls, Selection and information bias prone
Cross sectional study:
Basics
Pros + Cons
Collects data from population at a point in time (snapshot)
Pro: large sample size, Provides prevalence data
Cons: Risk of reverse causality (which came first)
What is reverse causality?
Outcome mau have been caused by exposure
E.g. in depressed people who are obese which caused which
Cohort study
Basic
Pros + Cons
Longitudinal study of similar groups getting different Tx/RFs
Follows them over time
Can follow up rare exposures
Allow Rfs to be identified
Takes a long time
High drop out rate
50 cases in 1000 people over ten years. What is the incidence per year?
10yrs
= 0.5% per year
How to calculate the relative risk (ratio)
(% with disease in exposed) / (% with disease in control)
How to calculate attributable risk of smoking
(% with disease in exposed) - (% with disease in control)
How to measure number needed to treat (the number which would save 1)
1/Attributable risk
%diseaseexposed - %diseaseunexposed
Wilson + Jungner screening criteria
INASEP
Important disease
Natural Hx under
Acceptable intervention
Simple + Safe
Effective Tx with early detection
Policy of who should get tx
Disadvantage of screening
Overdetection of subclinical disease
False +ve: worry and exposure to harmful further testing
False -ve: more dangerous as gives false sense of health
Positive predictive value
% of positives who are positive
Negative predictive value
% of negative who are negative
Sensitivity
% of those with the disease who are detected
Specificity
% of those without the disease who are negative
Lead time Vs Length time bias
Lead time = false sense of increased survival time due to early detection
Length time = a disease with a slower progression/low aggression more likely to be picked up by screening giving false idea screening is reason for good prognosis
PROGRESS mnemonic for health inequality
Place of residence
Race/Ethnicity
Occupation
Gender
Religion
Education
Socioeconomic status
Social capital resources
Definition of health:
A state of complete physical, mental and social wellbeing. No merely the absence of disease or infirmity
Causes of Errors
System Error
- staffing
- Equiptment unavailability
Human Error
- memory
- skill
- timing
Types of errors & model
Latent (system), Active (human)
Swiss cheese model
4 Questions in breach of negligence
1) Was there a responsibility of care
2) Was there a breach of duty
3) Was the patient harmed
4) Was the harm due to breach
3 domains of public health
Health Protection
Health improvement
Delivery of safe & high quality services
Aim of Health needs assessment
Systematic review to allow resource allocations which improve health equity and reduce inequalities
The 4 types of need (Bradshaw taxonomy)
Felt need (individual perception e.g. back pain need help)
Expressed need (Help seeking- going to Dr)
Normative need - Profession defines what intervention is needed
Comparative need compares the needs of different groups (e.g. diff locations)
3 approaches to to Health needs assessment
Epidemiological
- defines problem by looking at epidemiological data
Comparative
- Looks at services/health outcomes and compares to similar area
Corporate
- Asks local population / Health professionals/gov what needs are
Epidemiological HNA Pros and Cons
Uses existing data, Incidence morbidity/mortality, evaluate trends over time
Variable data qual, data collected may not be required, doesn’t consider felt needs
Comparative HNA Pros and Cons
Quick/Cheap, shows if better/worse than other areas
Difficult to find comparable
Corporate HNA Pros and Cons
Based on felt/expressed need
Make use of experience/knowledge
Cant establish need from demand, Vested interest, political agendas
Types of health behaviour
Health behaviour (prevent disease)
Illness behaviour (going to Dr)
Sick role behaviour (taking medication)
Transtheoretical model behaviour change
PCPMAN
Pre-contemplation (not ready yet)
Contemplation
Preparation
Action
Maintenance
Nudge model behavioural change
Nudge the env for positive change (e.g. fruit near checkout
Theory of planned behaviour
Three things lead to intention and subsequent behaviour
1) Attitude to the behaviour
2) Subjective norms (perceived social pressures)
3) Perceived behavioural control
What are never events
Serious
Largely preventable
Compromise in patient safety
Would not have occurred if preventative measures in place
- wrong site surgery, psych escape, wrong route chemo etc
What does egalitarian mean?
All people are equal and deserve equal rights and opportunities.
unfits of cohort study
Assessment of multiple RF
Assess rare disease
RCT can not be used to assess pathological exposures ethically
Role on communicable disease control consultant
Surveillance
Notification
Prevention
Causes of homelessness
Relationship breakdown
Domestic abuse
Dispute with parents
Bereavement
Barriers to healthcare for travellers
GPs reluctant to register
Communication difficulties
Lack of permanent site = poor continuity of care
Professional mistrust
Barriers for healthcare to homeless
Access
Lack of trust
Dont prioritise health (Maslows hierarchy)
Presenting illnesses of Asylum seekers
Common illnesses
Injuries from travelling/Malnutrition
Untreated Chronic disease
Lack of screening/Immunisations
Mental health: PTSD, depression, psychosis
Error of:
- Intention
- Action
- Outcome
- Context
Failure to achieve planned action. Skill/knowledge based
Task specific failure (e.g Wrong order / Omission of something in Tx)
Near miss/Death
Team/Env factors
Strategies to reduce errors
Simplification
Standardisation of procedures
Checklists
Practice/Training
How is risk identified
Audit
DATIX
Complaint forms
Relative reduction in risk
(Risk exposed - risk unexposed) / Unexposed
What can be offered to a Drug abuser
Health check
Screen for blood borne viruses
Contracepton
Smear and immunisation
Drug services info: Needle exchange
Principles in addiction management
Harm reduction (advise on risky behaviour_
Intervention: Explain risks, effects and advise on controlling use
Referral to specialist advice
Aims of drug use Tx
Reduce harm to under/family/society
Improve health
Reduce crime
What is domestic abuse?
Any incident/pattern
controlling, coercive, threatening behaviour
Violence or abuse
Between those aged over 16
Have been Intimate partners or family
Types of abuse
Psychological Physical Sexual Financial Emotional
Role of doctor in abuse
Healthcare records
Give helpline
Patient safety
Non-Judgemental
Domestic abuse levels of risk
Medium: RFs identified. Unlikely to happen without change in circumstance.
- give abuse contact details
High: risk of imminent harm
- Refer to MARAC (multi-agency risk assessment conference)
DASH score
Used for risk of domestic abuse
Domestic
Abusive
Stalking
Harassment
Equity Vs Equality
Equity identifies unequal needs which need proportional help
Definition of health need
Ability to benefit from an intervention
Positive and Negative conditioning in addiction
Positive: inc intensity of desire to use
Negative: Fear of withdrawal stops not quitting
Alcohol dependency
Tolerance Withdrawal Neglect of other activities Continued use despite negative effects Narrowing repertoire
Wernickes Triad
Ophthalmoplegia
Ataxia
Mental confusion
GIVE PABRINEX
Given to stop alcohol
Disulfram (sick)
Acamprosate (GABA blocker)
Emotional needs of elderly
Security Attention Autonomy Intimacy Part of community
Maslows hierarchy of needs Pyramid 1 (bottom) to 5 (tip)
1) Physiological (food, water, sleep)
2) Safety
3) Belonging and love (intimacy/friendship)
4) Esteem: feeling of accomplishment
5) Self actualisation (reaching full potential,)
Need fulfilled 1->5 Some people however to emphasise slightly differently
Epigenetics
Env influence on genetic regulation
Disease = Genetic predisposition + epigenetic changes
Child abuse
Abuse in someone under the age of 16
Major RF for domestic abuse
Preg
Threats
Obsessive
Prevention:
Primary
Secondary
Tertiary
Prevent onset of disease (vaccinations)
Detect pre-clinical level (screening)
Interventions arrest progress of disease
e.g. of cervical cancer
1 - HPV vaccine
2 - Screening
3 - Tx of cancer
Benefits of equity over equlity
Leads to equal health
Horizontal Vs Vertical Equity
H: Those in identical situations should get same Tx
V: Those in different situations treated differently
3 Domains of PH
Health improvement /Protection at:
1) Indvidual: patient education, immunisations etc
2) Community: Community health groups, green spaces, playgrounds, Vit D for at risk
3) Population: Screening, Sugar and alcohol tax, School meals, Fortified cereals, public smoke ban
Alc E.G.: 1) individual consumption levels, 2) Local alc sales/avail, 3) taxation
Theory of planned behaviour problem
Doesn’t take into account emotions or habit or routine
Typical Transition points for health behaviour
Leaving school Entering work Becoming parent Unemployment Retirement Bereavement
Can be +v or -ve
What is a meta analysis
Compiles stats of research in particular field to give one P-Value
Reason for risk taking behav
Unrealistic optimism (inaccurate perception of risk)
Top down needs management
Population level
Manage end result
Bottom up needs management
Individual approach.
Supplied, demanded and needed
Contraception, cataract, liability access
Types of needs assessment + resource allocation
Population/Subgroup e.g. Hillsborough
Condition e.g. COPD
Intervention e.g. Smoking cessation
5 step approach to HNA
1) Situational analysis (audit current practice)
2) Gap analysis
3) Methods of fixing
4) Implementation
5) Evaluation (re-audit)
What is methadone + what used for?
Opioid receptor agonist
Used in drug and alcohol misuse to prevent withdrawal
Alcohol issue in GP
Liver/Kidney failure
CVD
Cacer (2nd after smoking)
Alcohol Weekly
14 units (1 unit = 8g alcohol)
Alcohol related death
Accidents + Violence CVD Malignancies (Head and neck , liver, breast, stomach, pancreas) Cardiomyopathy (dilated) Cirrhosis
Alcohol in Preg
ESPECIALLY not 1st trimester
Underweight
Mental retardation
Facial appearance (Flat nasal bridge, epicanthic fold, Micrognathia)
Cardiac/Renal/Occular abnorm
Delirium tremens
- Cause
- Pres
- Tx
Dec alcohol in dependant individual
Hallucinations (lilliputian), Marked tremor
Supportive: fluids, BZD if fitting, Pabrinex
Alcohol screening
GGT
Carbohydrate deficient transaminase
CAGE
Model for healthcare evaluation
Donabedian model
Donabedian model sections
Structure (what resources, eg building staff eqpt)
Process (how is it done, eg how many patient seen, 2weel wait % etc)
Outcome (5Ds: Death, Disese, Disability, Discomfort, Dissatisfaction)
Problem with measuring health outcomes of service changes
lots of cofounders
Difficult to link cause and outcomes
Maxwells 6 dimensions of quality (EEEAAA)
Effectiveness (desired effect)
Efficiency (maximal output)
Equity (fair)
Acceptable
Access (cost, availability)
Approp (right Tx to right people)
When to notify of disease
One case of a notifiable disease
Contaminations (Infections e.g. restaurant, Chemical, Radiological)
Significant risk: chicken pox in healthcare worker, SARS
Social exclusion in the elderly initiatives
Age UK over 50 club, Dementia Cafes
What is the inverse care law
Care is inversely available to those who need it
Kordakoffs
Profound memory loss
Confabulation (fabricated, misinterpreted memories)
Gillick competence
Allows child under 16 to consent Tx if deemed Gillick competent
(Sufficient understanding + intelligence)
Fraser guidelines
Allows child with understanding to consent for contraception
When to break confidentiality for underage sex
Over 18
Position of power (e.g teacher, Dr etc)
