Session Twelve (Health Related Behaviour Models) Flashcards
What is a “Health Behaviour”?
Steptoe, 2010:
Activities that may help to prevent or detect disease and disability at an early stage promote and enhance health, or protect from risk of injury
What is a “Health Risk Behaviour”?
Steptoe, 2010:
Any activity undertaken by people with a frequency or intensity that increases risk of disease or injury
What is “Positive Health Behaviour”?
Any behaviour undertaken by a person who believes themselves to be healthy for the purpose of preventing disease or detecting it at an asymptomatic stage.
Ignores behaviours of those already ill undertaken behaviours to minimise their illness
Give some examples of health related behaviours?
- Going to appointments
- Adhering to medications
- Using sun cream
- Eating well
- Drinking water
- Sleeping
Why is health behaviour so important to healthcare in the UK?
Many of the most common causes of death in the UK are directly related to one or more health behaviours e.g:
- Heart disease
- Stroke
- COPD
- Resp cancers
Defra et al, 2008:
- 25% of deaths in young and Middle Aged adults are attributable to cardiovascular disease.
Furthermore, strong association between certain health behaviours and levels of all-cause morbidity and mortality (White et al, 2008)
What is the link between SES and health outcomes?
Recognised link between the two, however SES can only predict, and not explain, health outcomes.
Link likely related to some underlying association e.g we know smoking becomes more prevalent as you drop in SES.
Part of the reason HRBs are studied is to try and understand this relationship
Outline the findings of the Alameda County study, 1965?
Looked at 7 HRBs in 7000 adults:
- Lack of exercise
- Snacking between meals
- Smoking
- Sleeping (more than 8 vs less than 7)
- Skipping breakfast
- Regularly drinking 5 units of alcohol
- Weight (over vs under)
Found between these 7 factors you could reliably predict all-cause mortality.
Outline the findings from the EPIC-Norfolk study, 2008?
Found death rates to be inversely associated with four health factors:
- Not smoking
- Physical activity
- Moderate alcohol consumption
- Consuming 5+ Fruit and veg
Explain the difference between fixed and modifiable risk factors?
Fixed factors = things that can’t be changed in a consultation, don’t cause disease but predispose someone to disease e.g:
- Age
- SES
- Ethnicity
- Level of education
- Job status
Modifiable risk factors can be (theoretically) changed in consultations:
- Behaviours
- Emotions
- Cognitive factors such as beliefs and attitudes
- Social factors (modelling and observing, being around good habits)
- Environment (access, cultural, financial barriers)
Outline Rosenstock’s 1974 Health Belief Model?
An early theoretical model used to understand individual differences in behaviour, multiple components:
- Baseline factors: demographic (e.g. age, SES) and psychological (e.g. personality, social group)
- These affect common sense conditions which determine commitment to a behaviour, and include: Threat perception, Health motivation and Behavioural evaluation
- These in turn influence action (as does cues to that action)
What aspects if the Health Belief Model can be targeted by intervention
The middle 3 aspects, those that directly influence action.
- Threat perception: Both the perceived susceptibility and severity of the condition
- Behavioural evaluation: Perceived benefits and barriers around a HRB
- General health motivation
How practically useful is the HBM?
Moderately.
- In patients who (e.g.) see high threat, high benefit, low costs and are cued to the behaviour we can reasonably expect to see the behaviour
- In the opposite case can reasonably expect the behaviour not to occur
- Model fails when it comes to mixed cases, unpredictable
- Appears to depend on a number of personal factors which the model doesn’t really include
What evidence is there around the effectiveness of the HBM at predicting health behaviours?
Harrison et al, 1992:
- Meta-analysis of 16 studies into the impact of crucial HBM factors on health behaviour
- Measured Suceptibility, Severity, Benefits and barriers
- On the +ve side, found that all 4 were significantly correlated to behaviours (0.3 or greater)
- On the -ve side, total variance in behaviour explained by the model was only 10%
- Barriers best predictor, Severity weakest
Give some pros and cons of the HBM?
Pros:
- Furthered understanding of public health behaviour for educational interventions
- Variables ARE significant, in spite of small effect sizes
- Training health care professionals to work from patients subjective perceptions of illness and treatment
Cons:
- Reliant on self-reported evidence
- Doesn’t tell us anything about cost-benefit threshold
- Cross-sectional research measuring health beliefs and health behaviours at the same time
Give some examples of demographic and psych factors included in the HBM?
Demographic:
- Age
- Gender
- SES
- Education
Psychological:
- Personality
- Social group
- Temperament
How has the HBM been used to help patients engage in HRBs?
- Model provides a blueprint for health interventions
- But essentially if model can predict behaviour, opportunity to change predictors, change health outcomes
What did Hegel’s 1992 study into HBM intervention on dialysis patients show?
- Individual HBM-based educational interventions were compared to ‘reward for behaviour’ interventions vs combined group
- Weight gain between dialysis was marker of adherence (to fluid restrictions)
- No changes in core HBM factors; susceptibility, seriousness, benefits, concerns
- Reward for behaviour led to reduced reported barriers to behaviour
- Also lead to increased adherence in the long term
- HBM led to short term improvements, not maintained over time
- Combo condition no better or worse than just doing reward (suggests HBM is useless)
However this used a very small sample size and did not compare to treatment as usual
What did Ludwick et al’s 2001 breast self-examination study find about the HBM?
- Looked into 93 14-18 year olds
- Risks of contracting cancer were explained (thereby increasing knowledge, susceptibility and severity)
- Cue cards in shower (created cues to action)
- Demonstrated how to perform BSE (low barrier)
- Evaluated through questionnaire 1 month later
- Rates of not performing BSE dropped from 64% to 32%
Pros of this study: worked on every facet of HBM, suggests if applied properly can be effective
Cons: no control group, only followed them up in the short term, did not measure change in HBM factors therefore change wasn’t necessarily to do with HBM
What did Jones et al’s 2014 meta-analysis into the effectiveness of HBM methods show?
- 14/18 interventions based on HBM reported significant improvements in adherence
- However the success does not appear to depend on model constructs
- Overall evidence was limited in quality (lack of control groups, short follow-up, no randomisation)
What is the Theory of Planned Behaviour?
- Model designed after the HBM
- Ajzen et al, 1988
- Widely used to study cognitive determinants of intentions for health behaviours and health outcomes
- Deliberate processing model, assumes people’s attitudes and beliefs are formed after careful consideration of information available
- Fundamentally based on intention to perform a behaviour, therefore ignores potential barriers
- Makes the assumption that human behaviour is based on rational and careful consideration (which it isn’t)
Outline the ToPB?
Attitudes towards act or behaviour + Subjective norm + Perceived behavioural control –> Behavioural Intention –> Behaviour
- Perceived control also directly influences behaviour
- SNs = made up of what people think others want of them e.g. my doctor/family want me to do this AND social influence e.g. will I get made fun of for this
- There is a question marker over how BI leads to B, missing part of our understanding on how HRBs work.
Much research evidence around the ToPB has been around breastfeeding, give some exampled of how the various factors from the ToPB could influence breast feeding behaviour?
Attitudes:
- More positive beliefs and attitudes around breastfeeding
- e.g. Its good for the baby
Social Norm:
- More previous experience
- Others around you having that experience
Perceived Behavioural Control:
- Greater belief in their ability to successfully breastfeed
All have been shown to influence intention to breastfeed (McMillan et al 2008, Bai et al 2010)
What evidence is there around the link between ToBP factors and breastfeeding behaviour?
- Overall, effect sizes are small but significant.
- Evidence shows a gap between what they INTEND to do and what they actually do
- Ismail et al, 2016: ToPB accounts for 50% of intention but only 10% of behaviour
- McMillan et al, 2008: found the predictive utility of this model decreased over time (ToPB was able to effectively predict intention, sort of predict immediate behaviour, not really predict long-term behaviour)
- Wambach et al, 1997: Intention only accounted for 4% of variance of BF outcome at 4-6 weeks
What did McEachan’s 2011 meta-analysis of of the ability of the TPB to plan behaviour reveal?§
Massive variation, in terms of:
- TPB’s ability to create intension
- How much that intension actually translates to behaviour
There was also significant variation in how effective it was at different interventions e.g. adhering to medication vs exercising
