Tutorial 2 The Use of Data Flashcards
What is the definition of disease?
Diagnosis
Bio-medical perspective
What is the definition of the illness?
Experience
Patients perspective
What is an example of when disease is present but no illness?
Hypertension
This can cause problems when treating (medications)
What are some factors affecting the uptake of care?
- Concept of lay referral: “granny knows best”
- Sources of info: peers, family, internet TV, health pages of newspaper or women’s mag, “What should I do? Booklet, SHOW website, Practice leaflet or website
- Medical factors: new symptoms, visible symptoms, increasing severity, duration etc
- Non medical factors: crisis, peer pressure “wife sent me”, patient beliefs, expectations, social class, economic, psychological, environmental, cultural, ethnic, age, gender, media etc
What gender and age group visits the GP/practice nurse more?
Female Older ages (and very young, 4 & under)
What are some possible issues from the patients point of view?
Believes himself to be healthy.
Is physically fit.
Proud not to be using tablets.
Both he and his wife associate all illnesses to do with the Heart with Ischaemic Heart Disease.
If treatment is proposed, how would he feel better?
What are some possible issues from the GPs point of view?
You wish to perform a couple more tests: a Holter Monitor and an Echocardiogram
Assuming they return as confirming AF, you are worried about the consequences for Mr Blackwood’s long term health
What are the three aims of epidemiology?
Description: To describe the amount and distribution of disease in human populations.
Explanation: To elucidate the natural history and identify aetiological factors for disease usually by combining epidemiological data with data from other disciplines such as biochemistry, occupational health and genetics.
Disease control: To provide the basis on which preventive measures, public health practices and therapeutic strategies can be developed, implemented, monitored and evaluated for the purposes of disease control.
What does epidemiology compare and why?
It compares groups (study populations) in order to detect differences pointing too…..
It compares groups in order to detect differences pointing too…..
- Aetiological clues (what causes the problem)
- The scope for prevention
- The identification of high risk or priority groups in society
What does clinical medicine deal with?
The individual patient
What does epidemiology deal with?
Populations
What may a study population be defined by?
Age/sex/location
Numerator/Denominator
Numerator: number of events
Denominator: population at risk
What is relative risk?
This is the measure of the strength of an association between a suspected risk factor and the disease under study
How is relative risk (RR) calculated?
Incidence of disease in exposed group / incidence of disease in unexposed group
Give 6 sources of epidemiological data
Mortality data Hospital and clinical activity statistics Reproductive health statistics Infectious disease statistics Cancer statistics General practice morbidity statistics
What is health literacy?
Health literacy is about people having the knowledge, skills, understanding and confidence to use health information, to be active partners in their care, and to navigate health and social care systems
What has the Scottish Government published surrounding health literacy?
Making It Easy
What is the CHA2DS2-VASc score?
Clinical prediction rules for estimating the risk of stroke in patients with non-rheumatic atrialfibrillation (AF), a common and serious heart arrhythmia associated with thromboembolic stroke
What is the score used for?
Such a score is used to determine whether or not treatment is required with anticoagulation therapy
What does a higher score mean?
A high score corresponds to a greater risk of stroke, while a low score corresponds to a lower risk of stroke
A score of 1 means…
His annual stroke risk is 0.6% per year, and 0.9% of stroke/TIA/systemic embolism
What are NOACs?
Anticoagulants
These are newer drugs that do not require regular blood test monitoring like Warfarin
Patients will often have heard of them, and the lack of a need for monitoring often appeals to them
What are the downfalls of NOACs compared to Warfarin?
They are relatively expensive
They are not easily reversed like Warfarin, which can be reversed with Vitamin K in the event of bleeding
What can be used to calculate the risk of bleeding?
HAS-BLED
Estimates risk of major bleeding for patients an anticoagulation to assess risk-benefit in atrial fibrillation care
Bleeding risk needs to be weighed against the long term consequences of stroke
What are descriptive studies?
Descriptive studies attempt to describe the amount and distribution of a disease in a given population
What is the benefit of descriptive studies?
This kind of study does not provide definitive conclusions about disease causation, but may give clues to possible risk factors and candidate aetiologies.
What are the advantages and disadvantages of descriptive studies?
Such studies are usually cheap, quick and give a valuable initial overview of a problem. They do not provide evidence about the causes of disease. They do not test hypotheses.
What framework do descriptive studies follow?
The time, place, person framework
What are the 3 types of analytical studies?
- Cross-sectional study
- Case control study
- Cohort study
What is a cross-sectional study?
Disease frequency, survey, prevalence study
In cross-sectional studies, observations are made at a single point in time
What is the advantage and disadvantage of a cross sectional study?
A strength of this method is its ability to provide results quickly; however, it is usually impossible to infer causation
What is a case control study?
In case control studies, two groups of people are compared:
- a group of individuals who have the disease of interest are identified (cases),
- a group of individuals who do not have the disease (controls)
What is the point in a case control study?
Data are then gathered on each individual to determine whether or not he or she has been exposed to the suspected aetiological factor(s)
What are the results obtained from case control studies expressed as?
‘odds ratios’ or ‘relative risks’ (see above)
What are cohort studies?
In cohort studies, baseline data on exposure are collected from a group of people who do not have the disease under study.
The group is then followed through time until a sufficient number have developed the disease to allow analysis.
What do cohort studies allow?
Cohort studies allow the calculation of cumulative incidence, allowing for differences in follow up time
What are the results of cohort studies normally expressed as?
The results are usually expressed as relative risks (see above), with confidence intervals or p values
What are trials?
Trials are experiments used to test ideas about aetiology or to evaluate interventions
What is the definitive method of assessing any new treatment in medicine?
Randomised controlled trial
Name the 6 factors to consider in interpreting results?
Standardisation
Standardised Mortality Ratio
Quality of Data
Case Definition
Coding and Classification
Ascertainment
What is bias?
Bias is any trend in the collection, analysis, interpretation, publication or review of data that can lead to conclusions that are systematically different from the truth
What are the 5 types of bias?
Selection Bias Information Bias Follow up Bias Systematic Error Publication bias
What is a confounding factor?
A confounding factor is one which is associated independently with both the disease and with the exposure under investigation and so distorts the relationship between the exposure and disease.
In some cases the confounding factor may be the true causal factor, and not the exposure that is under consideration.
What are some common confounders?
Age, sex and social class
What are the criteria for causality?
Strength of association
Consistency
Specificity
Temporality
Biological gradient
Biological plausibility
Coherence
Analogy
Experiment
