SocPop Flashcards
Outline different ways of identifying normality
- Norms
- Socio-cultural Relativism
- Medico-statistical Normality
What are the Types of Normality?
Sociocultural Functional Historical Situational Medical Statistical Context dependent and Maladaptive Focus
Define Socio-Cultural Normality
Characteristic patterns of normal behaviours, attitudes, and beliefs within a group as a result of real or imagined group pressure
- Myers & Zimbardo
Define Functional Normality? How can this affect health?
Can individual function in the roles that have developed around them?
Depends on Context
Someone may think they can go to work so are fine but are suffering with disease
Define Historical Normality
How norms have changed from the past.
Smoking after WW2 thought to improve lung function but now know it does not. Banned in public spaces.
Can norms change?
Yes
Flexibility and progress
What is Maladaptation
- Adapting to behaviour/norm but to their detriment
- Can occur at self- to social level
Medical Normality
An expected state, Defined as Abnormal/Normal.
Abnormality establishes ‘the sick role’
Includes beliefs and attributions
What is Statistical Basis of Normality? Give an Example
Normal Distribution - 95% of Pop should be within +/- 2 Standard Deviations. Rest are Abnormal. Derived from measures of large populations
E.g. Birth Weight, Sperm Count, Serum Cholesterol, Blood Pressure
What is meant by Optimal Values
Give an Example
‘Normal value’ determined by what is required for optimal health. Not based on pop. averages.
e.g. BMI 20-25 Optimal Value. Glomerular Filtration Rate >90ml/min/1.73m2, Vitamin D >25nmol/l
What is Normality?
How does this relate to Medicine?
- Complex and Multi-factorial Concept
- Patients and Clinicians views may have very different views on Normality
- Norms change over time
Cite the sources of routinely collected demographic information
UK Census
Birth/Death Registration in UK
Population estimates and projections
Cite the sources of routinely collected Health Information
Cancer Registration
Hospital Episode Statistics
Quality and Outcomes Framework
Notifications of Infectious Disease
Cite the Source of Routinely Collected Health Information
Cancer Registration System
Hospital Episode Statistics
Quality and Outcomes Framework
Notifications of Infectious Disease
What is demography?
The study of the size, structure, dispersement, and development of human populations
What Information is collected in the UK Census
Demographic data, age/sex
Cultural characteristic, ethnicity/religion
Material deprivation - Employment, Home ownership, Overcrowding, Car access, Lone parents/Pensioners
Health
Workplace and journey
What is CART for Assessing Quality of Health information
Completeness Accuracy Representiveness/relevance Timeliness Accessibility
State Strengths of The UK Census
- 98% Complete
- Check of forms, coverage and quality surveys
- Data available for different levels from very local to whole country
- Access given to local councils
State Weaknesses of the UK Census
Low enumeration of some groups (e.g. undocumented migrants, uni students, travellers),
Self-reported
every 10 years, takes time for release
access - Individual returns confidential for 100 years
How is the UK Census used in service planning and delivery of care
- Population size & Structure: Young, old, minorities - Service needs them
- Base population (denominator) - Rates of disease
- measures of material deprivation - To identify and target inequalities
What is Birth Registration?
Measures of fertility. Crude births = Live births/1000 pop
General fertility rate
Total Fertility Rate (average number of children born per woman)
How is Birth Registration used in service planning and delivery of care?
Important for maternity services to know
Are there enough resources, anything abnormal?
What is Death Registration?
Collected by ONS - Death Certificates filled out after death. Cause of death very important for mortality statistics. Also covers underlying causes
How is Death Registration used in service planning and delivery of care?
Collected by ONS - Evaluating health and future needs to patients.
- Mortality Statistics
- Preventing the first disease or injury will result in the greatest population health gain
What are the Strengths of Using Mortality Data (Birth/Death Registrations)
- Complete coverage in UK
What are the weaknesses of using Mortality Data? (Birth/Death Registrations)
- Accuracy? Underlying cause of death subject to diagnostic uncertainty
- Ethnicity not collected, hard to evaluate differential survival rates
- Derivation of socio-economic status is posthumously inflated
Why are Population Estimates & Projections useful for planning services?
- Resource allocation
- in the past: Understand what has been happening in pop
- Present
- Future: to predict what is going to change/how change will affect pop
How are Population Estimates derived?
Estimate of population size & Structure between census
Census baseline + births - deaths + migration
Applies what is known to present
What are the Strengths of Using Population Estimates?
- More up to date figures than the census
- More accurate than projections
What are the limitations of using Population Estimates
- Less reliable with time from census (if it was done 8 years ago)
- Poor information on migration
- Says nothing about the future
What are Population Projections? How are they derived?
Forecast future population size and structure
- Based on assumptions about Mortality, Fertility, Migration
What are the strengths of Population projections? (1)
Can be used for longer term planning
What are the weaknesses of Population Projections?
- Less accurate the further ahead
- Unforeseen changes of past trends can invalidate projections
Give an Example of a Population Projection
- Projected age structure of the UK population over time.
What Implications can Population Projections have to health services if they show a projected increased life expectancy as disease management improves in the baby boom population?
- Increased cost of care for the elderly
- Increased need for chronic disease management
- Increased mental health issues e.g. Dementia
Explain the 3 Measures of Fertility
- Crude birth rate = Live births/1,000 pop
- General Fertility Rate = Live births/1,000 women aged 15-44yr
- Total Fertility Rate = Average number of children born per woman
What is the Cancer Registration System?
- National Cancer Registration and Analysis Service (NCRAS): Public Health England
- When someone diagnosed with cancer, triggers registration
- Data: Personal details, Diagnosis, Treatment, Outcomes
What are the Uses of the Cancer Registration System? (4)
- Prevalence of different cancers
- Evaluation and improvement of cancer treatment
- Evaluation of screening programmes
- Aiding Cancer Research
What are the Strengths of the Cancer Registration System?
Detailed information updated over time
Record linkage to cancer deaths (ONS) (Office of National Statistics)
What are the Weaknesses of the Cancer Registration System?
Expensive
Access is difficult due to confidentiality
What are Hospital Episode Statistics (HES)?
- Main source of all hospital data in the NHS
* Includes: All admissions, out-patient and A&E visits to NHS hospitals in England
What information is collected in Hospital Episode Statistics (HES)?
- Personal info (age, gender, ethnicity)
- Clinical Information (diagnosis and operations)
- Administrative date (Date of admission, discharge)
- Geographical Information - Where treated & lives
What are the Uses of HES
- BY: Commissioning orgs (payment), Provider orgs, Researchers
- For:
- Trends in NHS hospital activity
- Supports local service planning
- Health trends over time
- Fair access to healthcare
What are the two Main Coding classifications currently used in HES?
- ICD-10 (Internation Classification of Diseases, 10th Revision, WHO)
- OPCS-4 (OPCS Classification of Surgical Operations and Procedures, 4th Revision)
What are Strengths of HES
- Completeness - Covers all hospital activity
- Accuracy - Gold standard codes ICD-10, OPCS-4
- Representative - Routine National Data
What are Weaknesses to HES?
Accessibility - To individual data
What is QOF
Quality and Outcomes Framework
- Introduced in GP contract in 2004: Linked to GP payments, voluntary, rewarding good practice to improve care
What does QOF entail? 4 domains
- Clinical - Managing chronic diseases AF, Diabetes, CKD, Asthma, Dementia
- Public Health (CVD, BP, Obesity 18+, Smoking 15+)
- Public Health - Additional Factors (Cervical screening)
- Quality Improvement - Prescribing safely, end of life care
How does QOF work?
Points system - GP practices scored against indicators. Higher score = Higher GP income
- Significant Expenditure and significant incentive
Does Quality and Outcomes Framework improve outcomes?
NICE summary
- Recording? yes
- Process? - Mostly
- Intermediate/proxy outcomes? - yes for some
- Clinical outcomes? Unclear. Evidence for initially improved health outcomes for some conditions but subsequently fell to pre-existing trend.
Strengths of QOF
- Completeness - Almost 100% Response from GPs
- Representative - Representative of all population: Data at surgery, CCG, national levels
- Timeliness - Updated annually
- Access - QOF Online
Weaknesses of QOF?
- Completeness - Some do not participate
- Accuracy - Not sure how accurate/complete disease registers are for ind practices
- Representative - Only get aggregated data, no age/sex breakdown
- Access - Aggregated data only
What are Notifications of Infectious Diseases?
32 Notifiable diseases in England and Wales: E.g. Acute encephalitis, Infectious bloody diarrhoea, Mumps, Rubella, SARS, Tuberculosis.
- Doctor suspects notifiable disease case, must notify Public Health England, or labs.
- PHE collates and produces national trends each week
What are the uses of Notifications of Infectious Diseases?
- Surveillance
- Action to prevent further infection
- Identify outbreak
- Monitor trends
What are Strengths of using Notifications of Infectious Disease?
- Timeliness - Weekly Report by PHE
- Representative - Routine National Data
- Linked to other data to improve accuracy e.g. lab reports
What are the weaknesses of using Notifications of Infectious Diseases
- Poor or variable completeness for some diseases, e.g. not all food poisoning notified.
- Accuracy can be questionable due to diagnostic uncertainty. Asked to notify suspected cases
Name the National Source of Data for Prevalence of Diabetes
- Quality and Outcomes Framework
- Health survey for England
Name the National Source of data for Cancer Survival (2)
- National Cancer Registration and Analysis Service
* Hospital Episode Statistics
What data coding system is used in hospital for Surgical Procedures?
- OPCS-4
- Classification of Surgical Operations and Procedures, 4th Revision
- Records details of operations
What data coding system is used in hospital for the medical condition treated?
- ICD-10
- International Classification of Diseases, 10th Revision
- Describes conditions treated or investigated
Give 1 strength and 1 weakness of Death Statistics
- Advantage: Completeness - Complete record for all of UK
- Disadvantage: Accuracy - Underlying cause subject to diagnostic uncertainty
Ethnicity not collected
A patient is suspected to have malaria. After appropriate clinical management, what is the next step?
Notify ‘proper office’ at local council / Local Health Protection Team, part of Public Health England
What is Prevalence?
A measure of how common a disease is
Can be expressed as 1. Percentage 2. Number per n people
What are the different types of Prevalence?
- Point Prevalence
- Period Prevalence
- Lifetime Prevalence
How to Calculate Prevalence?
Proportion Prevalence = Number of People with Condition / Number of people in total
May have to multiply by n if it must be within n pop.
Must then accompany statistic within interpretation.
What is the Use of Prevalence? What are the Weaknesses of this?
- To gauge BURDEN of disease
- Prevalence can be affected by disease duration
- Does not consider when people got disease
What is Incidence (rate)?
The rate at which new events occur in a population, over a defined period of time
* Can be expressed as: 1. Per n people per time period 2. Per n person-years
Define Person-years
A measurement combining the no. of people observed and no. years observed for
Person-years = No. people x No. years
How to Calculate Incidence
Incidence rate = Number of NEW cases / (Number of People x Years observed)
May have to multiply by n to get per n person-years
Must accompany statistic with interpretation
How does Incidence and Prevalence Relate?
- High Prevalence + High Incidence = Common, not brief condition
- Low Prevalence + High Incidence = Common, very brief condition
- High Prevalence + Low Incidence = Uncommon, Long-term Condition
- Low Prevalence + Low Incidence = Uncommon, Short-term condition
What does it mean if a Disease has High Incidence + High Prevalence?
- High Incidence - High rate of new cases per year
- High Prevalence - At any point can find many people with disease
- E.g. Common cold
State Factors Affecting Prevalence
- Incidence Rate
- Recovery (cure) rate
- Transfer/Migration In and Out
- Death rate
What is Statistical Inference?
- Given that can’t sample entire population, don’t know true value. We make a best guess based on data
- Must describe our level of uncertainty around the best guess
What is Point Estimation
Best Guess based on Sample data
- Would a repeat generate same results? Unlikely
What is Sampling Error?
- Point estimates upon repeating experiment can be different. Will be clustered around the true value
- Differences between sample point estimates and the truth is the sampling error.
How can you Reduce Sampling Error?
Can test a larger sample
What is Standard Error
Is a numerical value that represents the sampling error
- Can be calculated
- Large SE suggests our best guess may be far from truth
- Larger sample size, smaller Numerical SE
What is Standard Error
Is a numerical value that represents the sampling error
- Can be calculated
- Large SE suggests our best guess may be far from truth
- Larger sample size, smaller Numerical SE
What are Confidence Intervals?
When giving estimate from a sample, should also give a range of plausible values, to represent level of uncertainty
How to Interpret Confidence Intervals?
’ You can be 95% Confident that, in reality, somewhere between … and … of … rest of interpretation.
What is the Calculation for Confidence Intervals?
- Lower bound: Point Estimate - (1.96 X SE)
* Upper bound: Point Estimate + (1.96 X SE)
Interpret: For Mothers holding their babies on the left.
• Sample proportion 0.8
• 95% CI of (0.76, 0.84)
- In our study, we found that 80% of mothers held their
- However, we can be 95% confident that the true proportion of mothers that hold their babies on the left is somewhere between 76% and 84%
How Can CIs be used to compare different groups?
- Can be used to see if there is a real (statistically Significant) difference between two groups.
- I.e. If CIs overlap - Not Significant
- If CIs do not Overlap - Significant
Who should the doctor notify in case of a Notifiable Infectious Disease case?
- Local Health Protection Team, Public Health England
* ‘Proper Office’ at Local Council
