Flashcards in ASBHDS - Session 2 Deck (47):
Define 'determinants of health'
A range of factors that have a powerful and cumulative effect on the health of populations, communities and individuals. Eg. physical environment, social/economic environment, individual genetics, characteristics and behaviours
Describe briefly the history of health promotion in developed countries
1910s-1940s: Public Health (reform of physical environment)
1950s-1960s: Health Education (target individual health behaviour)
1970s onwards: Health Promotion (broader political/social approach to health)
Define 'health promotion'
The process of enabling people to increase control over and to improve their health
What are the seven principles of health promotion?
What's the difference between health promotion and public health?
Public health places more emphasis on the end goals, while health promotion is about the MEANS of achieving the goals (education and healthy public policy).
What are the three aspects of health which are critiqued in a sociological perspective on health promotion?
1) structural critiques
2) surveillance critiques
3) consumption critiques
What are the five approaches to health promotion?
2) behaviour change
5) social change
What is the aim of primary prevention?
The prevent the onset of disease or injury by reducing exposure to risk factors
What are the approaches to primary prevention?
- prevention of contact with environmental risk factors
- taking appropriate precautions concerning communicable disease
- reducing risk factors from health related behaviours
What is the aim of secondary prevention?
To detect and treat a disease or its risk factors at an early stage to prevent progression/potential future complications and disabilities from the disease - mostly types of screening, eg screening for cervical cancer
What is the aim of tertiary prevention?
To minimise the effects of established disease, eg renal transplants or steroids for asthma
Explain this 'health promotion dilemma': the ethics of interfering in people's lives
- potential negative psychological impact of health promotion messages
- state intervention into individuals' lives may be seen as too great
Explain this 'health promotion dilemma': victim blaming
Focusing on individual behavioural change plays down the impact of wider socioeconomic and environmental determinants of health
Explain this 'health promotion dilemma': 'fallacy of empowerment'
Giving people information does not give them power, and unhealthy lifestyles are not due to ignorance but due to adverse circumstances
Explain this 'health promotion dilemma': reinforcing of negative stereotypes
Health promotion messages have the potential to reinforce negative stereotypes associated with a condition or group, eg leaflets aimed at HIV prevention in drug users suggest that they are to blame
Explain this 'health promotion dilemma': unequal distribution of responsibility
Implementing healthy behaviours in the family is often left to women
What is the 'prevention paradox'?
The idea that interventions that make a difference at population level might not have that much effect on the individual. This has a link with lay beliefs, as people may not see themselves as a 'candidate' for disease and therefore ignore the health warnings, and may also be aware of anomalies and randomness of disease
The rigorous and systematic collection of data to assess the effectiveness of a program in achieving predetermined objectives
Why must health programmes be evaluated?
- need for evidence based interventions
- ethical obligation
- programme management and development
What is process evaluation?
Focuses on assessing the process of programme implementation, and employs a wide range of mainly qualitative methods. AKA formative/illuminative evaluation
What is impact evaluation?
This assesses the immediate effects of an intervention. It is the more popular choice, as it is the easiest to do
What is outcome evaluation?
This measures more long-term consequences, eg improvement in patients' lives. The timing of the evaluation can influence outcome, as some interventions may take a long time or wear off quickly
What difficulties are there in demonstrating an attributable effect?
- design of intervention
- possible time lag to effect
- many potential intervening or concurrent confounding factors
- high cost of evaluation research (studies are likely to be large scale and long term)
What are the three ways in which a health professional may discover an illness in a patient?
- spontaneous presentation (patient presents with symptoms at GP/A&E/etc)
- opportunistic case finding (health professional takes opportunity to check for other potential conditions when person presents with symptoms related to a disease/problem)
The definitive identification of a suspected disease or defect by application of tests, examinations or other procedures (which may be extensive) to label people as either having or not having a disease
What is screening?
A systematic attempt to detect an unrecognised condition via tests, examinations or other procedures which may be applied rapidly and cheaply to distinguish apparently well persons who probably have a disease from those who probably do not
What is the purpose of screening?
To give a better outcome compared with finding something in the usual way, as treatment cannot wait until there are symptoms
What are the areas of criteria for whether there will be a national screening programme or not?
4) screening programme
What are the requirements of a particular condition for it to be screened for nationally?
- must be an important health problem in terms of frequency/severity with epidemiology, incidence, prevalence and natural history understood
- cost-effective primary prevention should have been implemented
What is a false positive?
This is when a test refers well people for further investigation
What are the impacts of a false positive?
- puts them through stress, anxiety and inconvenience of invasive diagnostic testing
- direct and opportunity costs
- may lead to lower uptake of screening in future
What is a false negative?
When people who have an early form of a disease are not referred
What are the impacts of a false negative?
- inappropriate reassurance may delay presentation with symptoms
- they will not be offered diagnostic testing which they needed
What are the general features of test validity?
- sensitivity (detection rate)
- positive predictive value
- negative predictive value
What is the detection rate?
The proportion of the people with the disease who test positive. This measures the sensitivity of the test.
How is sensitivity of a test calculated?
Divide the number of true positives by (true positives + false negatives) - basically divide amount of people who test positive by all the people who have the disease
What is the 'specificity' of the test?
The proportion of the people without the disease who test negative (correctly)
How is specificity calculated?
Divide true negatives by (false positives + true negatives) - basically divide people who don't have it and test negative by all the people who don't have it
What is a positive predictive value?
The probability that someone who tests positive for a disease actually has it - strongly influenced by prevalence of the disease
How is positive predictive value calculated?
True positives are divided by (true positives + false positives) - basically divide people who really have it and test positive by all the people who test positive
What is the negative predictive value?
The proportion of people who test negative who do not have the disease
How is negative predictive value calculated?
True negatives are divided by (false negatives + true negatives) - basically divide everyone who tests negative and doesn't have it by everyone who tests negative
What attributes must a screening programme have in order to be used nationally?
- proven effectiveness in reducing mortality/morbidity
- evidence that it is clinically, socially and ethically acceptable to health professionals and public
- benefit gained from individuals must outweigh harms
- opportunity cost must be economically balanced
What is lead time bias?
The idea that early diagnosis of a condition falsely appears to prolong survival when it does not. Patients live the same amount of time, but longer knowing they have the disease
What is length time bias?
The idea that screening programmes are better at picking up slow growing, unthreatening cases than aggressive, fast-growing ones, creating the illusion that screening helped loads when really it only picks up the easy cases
What is selection bias?
Studies of screening are often skewed by 'healthy volunteer' effect - those who have regular screening are also likely to do other protective activities