Block 3 Flashcards
Define health behaviours
Behaviours that are related to the health status of an individual.
3 types:
1. Good health behaviours
Sleeping (7-8 hours), regular exercise, healthy eating
2. Health protective behaviours
Wearing seatbelt, health screening
3. Health imparing habits
Smoking, high fatty diets, alcohol abuse
What are the determinants of health?
Background factors
Factors that define the context in which people live their lives
Stable factors
Individual differences (personality) in psychological activity that are stable over time and context
Social factors
Social connections in the immediate enviroment
Situational factors
Appraisal of personal relevance that shape responses in a specific situation
What drives seeking medical help?
Explanation of symptoms:
How they make sense of it in the context of their lives.
Perception of symptoms:
Frequency, severity etc.
Evaluation of symptoms:
Costs and benefits of seeking help.
What social triggers make us seek help?
Interference with relationships
Sanctioning by others
Interference with job/activities
Interpersonal crisis
Temporising of symptoms.
What are health behaviours?
Behaviours that are related to the health status of an individual
Explain the dual pathway model
There are two main ways that psychology can influence health:
Give examples of emotional dispositions that are important in determining health behaviours
OCEAN!
Openness
Conscientiousness
Extroversion
Agreeableness
Neurotic-ism.
Define locus of control
(Generalised expectancies)
Expectations that future events will be determined by internal (self) factors or external control (others, God etc.)
People with an internal locus of control tend to have better outcomes, as they believe they are in control of their health.
Define self-efficacy
(Generalised expectancies)
Belief in one’s own ability to organise and execute a course of action
And the expectation that the action will result in, or lead to, a desired outcome
What are the 3 broad types of individual differences?
1. Emotional dispositions
(present - psychological processes involved in both the expereince and expression)
2. Generalised expectancies
(future – psychological processes involved in formulating expectations in relation to future outcomes)
3. Explanatory styles
(past – psychological processes involved in explaining the causes of negative events)
Define optimism (Explanatory style)
Expectation of a positive future outcome despite current negative event
Linked to better physical health, illness recovery and health behavours
Define Attributional style
(Explanatory style)
Causal explanations of negative events as internal, permanent and global
What factors need to be considered when designing studies/interpreting results?
- Chance
- Bias
- Confounding factors
Define bias
“Any trend in the collection, analysis, interpretation or publication of data which allows conclusions to be drawn that are systematically different from the truth.”
Define publication bias
Rejection of unflavoured outcomes.
Prefers studies that support favoured theories.
Ie. That a drug works
Define recall bias
Caused by differences in the accuracy/completeness of the recollections obtained from study participants.
This is a type of information bias, as it affects the information received as data.
Define selection bias
Bias in choosing who will take part in the study.
Ie. One might choose patients with less severe symptoms in order to prove that a drug works.
Define confounding factors
An additional, unmeasured variable that is connected to both the dependent and the independent variable.
Eg. Obesity and CHD, smoking may be a confounding factor.
When must bias be considered?
Bias must be considered when interpreting results from a study.
What is the Bradford Hill criterion for causality?
Group of minimal conditions necessary to provide adequate evidence of a causal relationship between an incidence and a consequence.
Critera includes:
- Strength of assciation
- Specificity of association
- Consistency of association
- Temporal sequence
- Dose response
- Reversibility
- Coherence of theory
- Biological plausibility
- Analogy
Describe the hierarchy of evidence
What are the types of bias?
1. Selection
Admission, prevalence/incidence, detection, volunteer, loss to follow up
Error in choosing the individuals or groups to take part in the study leads to the distortion of the analysis.
Needs to be taken into account when making conclusions about the study.
2. Information
Interviewer, questionnaire, recall, diagnostic suspicion and expose.
Bias that arises from measurement error.
3. Confounding
Define reverse causality
Like the chicken or the egg.
Which is the causality and which is the outcome?
Ie. Mental health problems can cause unemployment but unemployment can cause mental health problems.
Define ‘the number needed to treat’
The number of people that would have to receive the treatment in order to prevent one negative outcome.
NNT = 1/AR
What is the difference between observational studies and experimental studies?
Observational studies measure variables of interests in subjects as opposed to actively giving treatments/intervening in any way.
Experimental studies intervene, setting specific variables for differences between groups.
Define descriptive observational studies
Examines distributions.
Ie. what is the prevalence?
Define analytical observational studies
Examines determinants.
Ie. What exposures increase risk?
What are ecological studies?
Studies that compare an area or population with another.
Ie alcohol consumption of UK to France
What is the ‘ecological fallacy’
The ecological fallacy is thinking that relationships observed for populations hold for individuals:
ie. if populations with more protestants tend to have higher suicide rates, then protestants must be more likely to commit suicide.
What are the pros and cons of ecological studies?
Pros:
Easy to do as information available
Cheap
May raise hypothesis
Cons:
Work on whole population data so cannot be applied to individual persons
Cant establish cauasation only association
Ecological fallacy
Less reliable data collection (disadvantage related to cross-sectional studies)
Confounding
What are cross-sectional studies/surveys?
A study in which information is collected from each subject in the study population at one point in time.
eg. survey
What are the pros and cons of cross-sectional studies/surveys?
Pros:
Cheap and simple
Good for examining exposures that do not change over time (sex)
No exposure to harm or denial of beneficical therapy
May raise hypothesis
Cons:
Cannot establish causation only association
Cannot measure incidence
Confounding
Recall bias
Response rates (dependent on this factor)
Define Case-control studies
Involve comparing subjects with a condition (the cases) to subjects without the condition (the controls).
This involves comparing the exposure of both groups to certain factors.
If the prevalence of an exposure is higher in cases then in controls then it is thought that the exposure may be a risk factor.
What is the odds ratio (equation)?
Odds ratio is the odds in one category over the odds in another category.
Interpret an odds ratio with its 95% confidence interval
(4 point interpretation)
- Odds ratio estimate – best estimate of the odds of the outcome in the population
- 95% CL – 95% confident that the population odds ratio lies between these two limits
- Is the null hypothesis included in the 95% confidence interval
- Is it statistically non-/significant at the 5% level
How many controls per a case is optimum?
The precision of the OR is affected by the number of healthy people (b and d).
Hence is it worth increasing the number of controls; typically up to 4-6 times as many controls as there are cases.
What are the pros of Case-Control studies?
Shorter than cohort studies
Cheaper than cohort studies
Good for studying rare events (which are not studied best via cohort studies as they need a large sample size)
Multiple exposures can be examined
No loss to follow
Suitable when randomisation is unethical (alcohol and pregnancy outcome)
What are the cons of Case-Control studies?
Prone to biases i.e. recall
Problems sorting out sequence of events
Not suited for rare exposures
Cannot measure disease incidence
Multiple outcomes cannot be studied