Public Health Flashcards
1
Q
What are the determinants of health?
A
- Genes (Age, Sex, Genetics)
- Environment (Physical and socioeconomic)
- Lifestyle (Smoking, exercise, alcohol, diet)
- Healthcare
Wider determinants = inequalities in health, primary, secondary and tertiary prevention
2
Q
What are the structural determinants of health?
A
Socio-economic context that someone is born into
- governance
- Policies
- Social and cultural values communities place on health
3
Q
What factors determine someones socio-economic position in society?
A
Education Occupation Income Gender Ethnicity Social class
4
Q
What are the intermediary determinants of health?
A
- Material Circumstances (Housing, clothing, food)
- Psychosocial living circumstances
- Behavioural and biological factors
5
Q
Define Equity
A
What is fair and just - “Health equity is defined as the absence of unfair and avoidable or remediable differences in health among population groups defined socially, economically, demographically or geographically”.
6
Q
Define horizontal equity
A
equal treatment for equal need (Ie. individuals with the same disease should be treated equally)
7
Q
Define vertical equity
A
Unequal treatment for unequal need (Ie. individuals with common colds need different treatment to those with pneumonia)
- Areas with poorer health may need higher expenditure on health
Vertical equity – is the unequal treatment of unequals and can be justified on the basis of morally relevant factors, however, morally irrelevant factors should not be the basis for employing vertical equity:
Morally relevant factors:
Need
Ability to benefit
Autonomy
Deservingness
Morally irrelevant factors:
Age/sex*
Ethnicity
Income, class
Disability, genetics
8
Q
How can health equity be classified?
A
(i) Spatial = geographical
(ii) Social = Age, gender, class, ethnicity
9
Q
How can we examine health equity?
A
- supply of healthcare
- Access to healthcare
- Utilisation of healthcare
- Health care outcomes
- health status
- Resource allocation (Health services, education, housing)
- Wider determinants of health (diet, smoking, healthcare seeking behaviour, socioeconomic and physical environment)
10
Q
What are the three domains of public health practice
A
- Health improvement
- Health protection
- Healthcare (Improving services)
11
Q
What is meant by health improvement domain
A
Concerned with societal interventions aimed at preventing disease, promoting health and reducing inequalities through engagement with social determinants such as housing,education, employment, lifestyles, family and community)
12
Q
What is meant by health protection domain
A
Concerned with measures to control infectious disease risks and environmental hazards
(infectious disease, chemicals and poisons, radiation, emergency response, environmental health hazards)
13
Q
What is meant by the healthcare domain
A
Organisation and delivery of safe, high quality services for prevention, treatment and care (clinical effectiveness, efficiency, service planning, audit and evaluation, clinical governance, equity)
14
Q
Give some examples of the health improvement domain
A
Addressing inequalities Education Housing Employment Lifestyle Family/community
15
Q
Give some examples of health protection domain
A
Infectious disease Chemicals and poisons Radiation Emergency response Environmental health Hazards
16
Q
Give some examples of the health care domain
A
Clinical effectiveness Efficiency Service planning Audit and evaluation Clinical governance Equity
17
Q
What are the three levels that a public health intervention can occur at
A
- Individual level
- Community level
- Ecological (Population) Level
18
Q
Give an example of an individual level public health intervention
A
Childhood immunisations where injections are delivered to each individual child to stop them getting ill
19
Q
Give an example of an community level public health intervention
A
Similar to ecological level interventions but delivered at the local or community level (ie. Playground set up for local community, more cycle paths, outdoor gym)
20
Q
Give an example of an ecological level public health intervention
A
Clean air act - legislation to ban smoking in enclosed public places
Putting iodine in salt to prevent iodine deficiency)
21
Q
Define health psychology
A
Emphasises the role of psychological factors in the cause, progression and consequences of health and illness and promotes healthy behaviours and prevents illness
22
Q
What are the 3 behaviours related to health?
A
- Health behaviour
- Illness behaviour
- Sick role behaviour
23
Q
Define health behaviour
A
A behaviour aimed at preventing disease (Eating healthily)
24
Q
Define an illness behaviour
A
A behaviour aimed at seeking remedy (Going to the doctor)
25
Define a sick role behaviour
Any activity aimed at getting well (Taking prescribed medication)
26
Give some examples of public health campaigns at population level
Awareness campaigns (Healthier you, change 4 life, every mind matters)
Screening and immunisation (Smear and MMR Vaccine)
27
What is unrealistic optimism
When individuals continue to practice health damaging behaviour due to inaccurate perceptions of the risk and susceptibility
28
What factors influence an individuals perception of risk?
Lack of personal experience with the problem
Belief that the risk is preventable by personal action
Belief that if something hasn't happened by now then its not likely to happen
Belief that the problem is infrequent
29
In terms of health needs assessment, define need
Ability to benefit from an intervention (Ie. Minimum unit pricing for alcohol)
30
In terms of health needs assessment, define demand
What people ask for (ie. Cosmetic surgery)
31
In terms of health needs assessment, define supply
What is provided (Tamiflu stockpiles for influenza)
32
What is a health needs assessment
Systematic method for reviewing the health issues facing a population leading to agreed priorities and resource allocation that with improve health and reduce inequalities
33
Define health need
Need for health - concerns measures of mortality, morbidity and socio-demographic measures
34
Define healthcare need
Need for healthcare and the ability to benefit from healthcare - potential for prevention, treatment and care services to remedy health problems
35
What three things might a healthcare assessment be carried out for
1. Population or subgroup
2. A condition (COPD)
3. An intervention (Coronary Angioplasty)
36
Define felt need
Individual perceptions of variation from normal health
37
Define expressive need
Individuals seeks help to overcome variation in normal health (Demand)
38
Define normative need
Professional defines intervention appropriate for the expressed need
39
Define comparative need
Comparison between severity, range of interventions and cost
40
What are the three approaches to health needs assessments
1. Epidemiological
2. Comparative
3. Corporate
41
Describe the epidemiological approach to health needs assessment
1. Define the problem
2. Size of the problem (Prevalence and incidence)
3. Services available (Prevention/treatment/care)
4. Evidence base (Cost effectiveness and efficacy)
5. Models of care (Quality and outcome measures)
6. Existing services (Unmet need, services not needed)
7. Recommendations
42
What are the 4 sociological perspectives of need?
1. Felt need
2. Expressed Need
3. Normative Need
4. Comparative Need
43
What are the potential sources of data for an epidemiological health needs assessment
1. disease registry
2. Hospital admissions
3. GP databases
4. Mortality data
5. Primary data collection (Postal/patient survey)
44
What are the advantages of an epidemiological health needs assessment
1. Uses existing data
2. Provides data on disease incidence/mortality/morbidity
3. Can evaluate services by trends overtime
45
What are the disadvantages of an epidemiological health needs assessment?
Required data not available
Variable data quality
Evidence based may be inadequate
Does not consider the felt needs or opinions/experiences of the people affected
46
Describe a COMPARATIVE approach to a health needs assessment
Compares the services received by a population with others
- Spacial
- Social (Age, gender, class, ethnicity)
ie. Compares the services for a particular health issue in two different areas
47
What factors might a comparative health needs assessment examine
1. Mental status
2. Service Provision
3. Service utilisation
4. Health outcomes (Mortality, morbidity, QOL, patient satisfaction)
48
What are the advantages of a comparative health needs assess
Quick and cheap data available
Indicates whether health or derives provision is better/worse than comparable areas (Gives a measure of relative performance)
49
What are the disadvantages of a comparative health needs assessment?
1. May be difficult to find a comparative population
2. Data may not be available or of a high quality
3. Data may not yield what the most appropriate level of provision or utilisation should be
50
What does the corporate approach to health needs assessment involve
Asks the local population what their health needs are
Uses focus groups, interviews and public meetings
Involves a wide variety of stakeholders including teachers, healthcare professionals, social workers, charity workers, local businesses, council workers and politicians
51
What are the advantages of corporate health needs assessments
Based on the felt and expressed needs of the population in question
Recognises the detailed knowledge and experience of those working with the population
Takes into account a wide range of views
52
What are the disadvantages of a corporate health needs assessment
Difficult to distinguish need from demand
Groups may have invested interests
May be influenced by political agendas
Dominant personalities may have undue influence
53
Define primary prevention
Preventing disease before it has happened
54
Give an example of primary prevention
Change4life
| 5 a day
55
Define secondary prevention
Catching a disease in its early pre-clinical phase
56
Give an example of secondary prevention
Breast screening
57
Define tertiary prevention
Preventing the complications of a disease
58
Give some examples of tertiary prevention
Diabetic foot care
Attending physio/rehab after a stroke to prevent immobility and aspiration pneumonia
59
What is the definition of an evaluation of health services
Assessment of whether a service achieves its objectives or not - a process that attempts to determine as systematically and objectively as possible the relevance, effectiveness and impact of activities in the light of their objectives
60
What can an evaluation of health services include
1. Single intervention (RCT evaluating effectiveness of new cancer drug)
2. Public health interventions (impact of smoking ban on health using epidemiological studies)
3. Health economic evaluation (Evaluating cost-effectiveness of a medical intervention)
4. Health technology assessment (Incorporate systematic review, economic evaluation and mathematical modelling
61
A health service evaluation is based upon which framework
DONAEDIAN (Structure, process, output and outcome)
62
What three things make up the framework for a health service evaluation
1. Structure
2. Process
3. Outcome
63
What sort of things would be evaluated for the structure part of a health service evaluation
Buildings (number of ICU beds per 1000 population)
Staff (Number of vascular surgeons per 1000 population)
Equipment (Locations where screening is provided)
64
What sort of things are evaluated for process part of a health service assessment
What is done
ie. Number patients seen on A&E
Process through which patients go into A&E
(Where and when patient is first seen, who carriers out triage, how priority is assessed)
Number of operations performed
65
What sort of things would be evaluated to assess outcomes in a health service assessment
Classification of health outcomes
1. Mortality (30 day mortality rate)
2. Morbidity (Complication rate)
3. QOL/Patient reported outcome measures (PROMS)
4. Patient satisfaction
66
What is another way to assess OUTCOMEs in a health service assessment
```
the 5D's
Death
Disease
Disability
Discomfort
Dissatisfaction
```
67
What are some examples of Patient reported outcome measures (PROMS) questionnaires used in primary care?
Oxford hip score
Oxford knee score
EQ-5D
Aberdeen varicose vein questionnaire
68
What are some of the condition specific questions found on the Oxford hip score
1. During past 4 weeks, how would you describe the pain you usually had from your hip?
2. During the past 4 weeks, have you had any sudden, severe pain (Shooting, stabbing) from the affected hip?
3. During the past 4 weeks, have you been troubled by pain from your hip in bed at night?
69
What are some issues with health outcomes in an evaluation
Link between the health service provided and the health outcome may be difficult to establish as there may be other factors involved (Severity, confounding factors)
Time lag between the service provided and the outcome may be long (Healthy eating in childhood and T2DM incidence in middle age)
Large sample sizes needed to detect statistically significant effects
Data not available
Issues with the quality of data
70
When assessing the quality of health services, what are 6 dimensions of Maxwell's classification
3 A's and 3 E's
1. Effectiveness (Does the intervention produce the desired effect)
2. Efficiency (Is the output maximised for a given output)
3. Equity (Are the patients being treated fairly)
4. Acceptability (How acceptable is the service offered to the people needing it)
5. Accessibility (Geographical access, costs for patients, information available, waiting times)
6. Appropriateness (Is the right treatment being given to the right people at the right time)
71
What are the 2 different methods which can be used for a health needs assessment
1. Qualitative
- consult relevant stakeholders (Staff patients, relatives carers
Methodology
- observation (Participant observation, non-participant observation).
Interviews
Focus groups
Review of documents
2. Quantatative Methods
- Routinely collected data (Hospital admissions/mortality)
- Review of records (Medical and administrative)
- surveys
- Other special studies using epidemiological methods
72
What is the definition of domestic abuse
Controlling, coercive, threatening behaviour, violence or abuse between those aged 16 or over who are or have been intimate partners or family members
(Psychological, physical, sexual, financial and emotional abuse)
73
What are the 3 main ways in which domestic abuse presents to healthcare
1. Traumatic injuries following assault (Fractures, bleeding, bruising)
2. Somatic problems or chronic illness consequent from living with abuse (Headache, GI disorder, chronic pain and premature delivery)
3. Psychological or psychosocial problems secondary to abuse (PTSD, attempted suicide, substance misuse, depression, anxiety, eating disorders)
74
What is the role of a doctor if they suspect a case of domestic abuse
Try and speak to them alone (i.e. away from their partner and away from their children)
Document EVERYTHING THEY SAY
Document what their injuries look like
Only report to the police if it’s safe to do so - focus on safety
Tell them you can help them and point them in the right direction for proper support
Display posters about helplines etc. in your GP surgery
Ask direct questions – be non-judgement and reassuring
75
Which tool can be used to assess domestic abuse?
DASH (Domestic abuse and sexual harassment tool)
76
What do you do if you think someone is at medium/standard risk of domestic abuse?
Its their choice what they do
Give them contact details for domestic abuse services and let them decide what to do
77
What do you do if you believe someone is at high risk of domestic abuse?
Refer to MARAC/IDVAS wherever possible with consent
In high risk, you can break confidentiality if you don't get their consent but always try and get consent first
78
What is the role of domestic homicide review
Circumstances in which the death of a person aged 16 or over has or appears to have resulted from violence, abuse or neglect
79
What is health psychology
Emphasises the role of psychological factors in the cause, progression and consequences of health and illness
80
What is the theory of planned behaviour
Proposes that the best predictor of behaviour is INTENTION - 'I intend to give up smoking'
81
What are the three factors that determine intention in theory of planned behaviour
1. Person's Attitude (I do not think smoking is a good thing)
2. Subjective Norms (Perceived social pressure to undertake a behaviour - people who are important to me want me to give up)
3. Perceived behavioural control (A persons appraisal of their ability to perform the behaviour - I CAN give up smoking)
82
What are some criticisms of the theory of planned behaviour
Doesn't take into account emotions (Fear, threat)
Relies on self reported behaviour (People may lie)
Lack of temporal element (no timescale)
Lack of direction or causality Assumes attitudes, subjective norms and perceived behavioural control can be measures
Habits and routines bypass cognitive deliberation and undermine a key assumption of the model
83
How do we bridge the intention to behaviour gap in the theory of planned behaviour
Perceived control = ask them to reflect on how they felt when something went well (Ie saying no to a cigarette)
Anticipated regret = reflect on how they felt when they didn't do something (When they weren't able to say no to a cigarette)
Preparatory actions = remind people to prepare for their change of behaviour (Throw cigarettes away)
Implemented intentions = help them help themselves incorporate the behaviour change into their routine (Putting tablets next to the kettle)
Relevance to self
84
What are the 6 stages of transtheoretical model/stages of change model - give an example of each
1. Pre-contemplation = haven't thought about stopping smoking
2. Contemplation = thinking about stopping
3. Preparation = goes to doctor, gets prescription of champix, sets stop date, throws away cigarettes
4. Action = stops smoking on quit date and uses medications to help
5. Maintenance = Continues to abstain from smoking by going for regular reviews and picking up more medication
6. Relapse - potential relapse after trigger type event
85
What are the advantages of the transtheoretical models
Acknowledges individual stages of readiness (Tailored interventions)
Accounts for relapses and allows patients to move backwards in stages
Gives an idea of time frame (Temporal element)
86
What are the criticisms of the transtheoretical model
Not all people move through every stage, some move backwards and some miss stages completely
Change might operate on a continuum rather than in discrete stages
Doesn't take into account values, habits, cultures, social and economic factors
87
What are the 4 factors of the health beliefs model
Individuals will change if
1. Believe they are susceptible to the condition in question (Heart disease) (Perceived susceptibility)
2. Believe that it has serious consequences (Perceived severity)
3. Believe that taking action reduces susceptibility (Perceived benefits)
4. Believe that the benefits of taking action outweighs the costs (Perceived barriers)
88
What are the criticisms of the health belief model
Alternative factors may predict health behaviours such as outcome expectancy (Whether the person feels they will be healthier as a result of the behaviour) and self efficacy (Persons belief in their ability to carry out preventative behaviour
Does not consider the influence of emotions on behaviour
Does not differentiate between first time and repeat behaviour
Cues to action are often missing
89
What is the role of motivational interviewing?
A counselling approach for initiating behaviour change by resolving ambivalence (State of having mixed feelings or contradictory ideas about something)
Role is to allow someone to change their behaviour by helping them to make a decision about the behaviour - helping someone to see that smoking is bad for them
90
What is meant by the nudge theory
Change the environment to make the best/healthiest option the easiest
ie. placing fruit next to checkouts at supermarkets rather than sweets, opt-out pension schemes
91
What are the typical transition points in life which may influence how someone changes their behaviour
1. Leaving school
2. Starting work/new job
3. Becoming a parent
4. Becoming unemployed
5. Retirement
6. Bereavement
92
In the health belief model, what are some of the cues to action which may influence behaviour change
Internal (Increase in pain, decrease in ADLs)
External (Reminders in the post, reminders for GP appointments, pressure from families
93
What are some other factors to consider when it comes to behaviour change
Impact of personality traits on health behaviour
Assessment of risk perception
Impact of past behaviour/habit
Automatic influences on health behaviour
Predictors of maintenance of health behaviours - does it stay changed 6 months down the line
Social environment
94
What impact does social norms have on health behaviours
Social norms = behaviours and attitudes most common in a group
Providing truth about social norms could decrease high risk behaviours
- doesn't work when risky behaviour is the social norm
95
What do NICE advice we do about behaviour change
1. Planning interventions
2. Assessing social context
3. Education and training
4. Individual level interventuons
5. Community level interventions
6. Population level interventions
7. Evaluating cost effectiveness
8. Assessing cost effectiveness
96
What are the GIT side effects of opioids
Constipation
Nausea
Results from stimulation of K and Mu receptors in the GIT
97
What are the respiratory effects of opioids
Sleep apnoea, ataxic breathing, hyperaemia and CO2 retention, respiratory depression
98
What are the cardio effects of opioids
Increased incidence of cardiovascular events
99
What are the CNS effects of opioids
Dizziness, sedation leading to falls, fractures and respiratory depression
Hyperalgesia associated with excessive sensitivity to pain
100
What are the MSK effects of opioids
Risk of fractures in the elderly
101
What are the endocrine effects of opioids
Interact with pituitary adrenal axis affecting the release of anterior pituitary hormones including GH, prolactin, TSH, ACTH and LH
Decreased gonadotrophin = in males hypogonadism, sexual dysfunction, infertility, fatigue, decreased levels of testosterone = metabolic syndrome
Decreased gonadotrophin in females leads to low oestrogen, Osteoporosis, oligomenorrhoea and galactorrhea
102
What are the effects of opioids on the immune system
Affect the U receptor on all immune cells
103
What behaviours might suggest someone has an addiction or is misusing opioids
Increasing dose without prescription
Obtaining additional opioids from other doctors
Purposeful sedation
Uses for purposes other than pain relief
Hoarding pain medications
104
What are the side effects resulting from continued opioid use
```
Tolerance
Withdrawal
Weight gain
Reduced fertility
Irregular periods
ED
Hyperalgesia
Depression
Dependence
Addition
Reduced immunity
Osteoporosis
Constipation
```
105
What are the non-pharmacological options for treating pain
Physical (Weight loss, smoking cessation, exercise, Yoga, pilates, joint injections)
Psychological (Counselling, CBT, Music, Meditation, relaxation)
Complementary therapy (Massage, Reflexology)
Occupational (Work place based review)
106
What are the pharmacological options for chronic pain
Non-opioid (NSAIDs, COX-2 inhibitor, Paracetamol)
Opioid (intermittent use at slow and low dose)
Adjuvant analgesics (Anti-convulsants, anti-depressants, lidocaine patches)
107
What are the signs abuse and dependency of opioids
Use of pain medications other than for pain
Impaired control
Compulsive use of medication
Continued use of mediation despite harm or lack of benefit
Craving or escalation of medication use
Selling or altering prescriptions
Stealing or diverting medications
Calls for early refills or losing medication
Reluctance to try non-pharmacologic interventions
108
Define epidemiology
Study of frequency, distribution and determinants of diseases and health related states in populations in order to prevent and control disease
109
Define incidence
Number of new cases of a disease in a population in a given time frame (new cases per 1000 per year
110
Define prevalence
Existing cases in a population at a point in time (Total number of people with a condition per 100,000 per year
111
What is person time
Measure of time at risk ie. time from entry to a study to
1. Disease onset
2. Loss to follow-up
3. End of study
Used to calculate the incidence rate which uses person time as the denominator
112
Define incidence rate
Number of persons who have become cases in a given time period/ total person time at risk during that period
113
What is meant by absolute risk
Actual numbers involved and has units (Ie. 50 deaths per 1000 people
114
What is meant by relative risk
Ratio of risk of the disease in the exposed compared to the risk in the unexposed (No units
Tells us the strength of association between risk factor and disease
115
What is meant by attributable risk
Rate of disease in the exposed that may be attributed to the exposure
116
How do we calculate attributable risk
Incidence in exposed - incidene in unexposed
117
What is meant by relative risk
Ratio of the risk of disease in the exposed to the risk in the unexposed
Tells us about the strength of association between a risk factor and a disease
118
How do we calculate relative risk
Incidence in the exposed / incidence in unexposed
119
If the incidence of disease A in smokers is 1/1000 person years and 0.05/1000 person years in non smokers, what is the attributable risk?
1-0.05 = 0.95/1000 person years
120
If the incidence of disease A in smokers is 1/1000 person years and 0.05/1000 person years in non smokers, what is the relative risk
1/0.05 = 20 (no units)
121
If the incidence of disease B is 8/1000 person years and incidence of disease B in non-smokers is 4/1000 person years what is the attributable risk?
8 - 4 = 4/1000 person years
122
If the incidence of disease B is 8/1000 person years and incidence of disease B in non-smokers is 4/1000 person years what is the relative risk?
8/4 = 2 (No units)
123
What is relative risk reduction
Reduction in the rate of the outcome in the intervention group relative to the control group
124
How do you calculate relative risk reduction
(Incidence in non-exposed - incidence in exposed) / incidence in non-exposed
125
What is absolute risk reduction
Absolute difference in the rates of events between the 2 groups
Gives an indication of the baseline risk and the intervention effect
126
How is absolute risk calculated
incidence in non-exposed-incidence in exposed
127
Define number needed to treat
Number of patients needed to treat to prevent one bad outcome
128
How do you calculate number needed to treat
NNT = 1/(Risk in the non-exposed - risk in exposed)
Aka 1/absolute risk reduction
129
What is meant by odds
Odds of an event is the ratio of the probability of an occurence compared to the probability of a non-occurrence
130
How do you calculate odds
Probability/(1 - Probability)
131
What are the 5 factors that could be responsible if a study finds an association between exposure an outcome
1. Bias
2. Chance
3. Confounding factors
4. Reverse causality *one thing is actually causing the other
5. A true casual association
132
Define bias
A systematic deviation from the true estimation of the association between exposure and outcome
133
What are the three main types of bias
1. Selection bias
2. Information (measurement) bias
3. Publication bias
134
What is a selection bias
A systematic error in
1. Selection of study participants
2. Allocation of participants to different study groups
135
What are some examples of selection bias
Non response
Loss to follow up
Those in the intervention group different in some way from the controls other than the exposure in question
136
What is an information/measurement bias
A systematic error in the measurement or classification of the exposure or outcome
137
What are some potential sources of information/measurement bias
Observer bias
Participant - recall/reporting bias
Instrument - wrongly calibrated instrument
138
What is meant by confounding
A situtation in which the estimate of association between an exposure and outcome is distorted because of the association with another factor that is also independently associated with the outcome
139
What is meant be reverse causality
Refers to a situation when an association between an exposure and an outcome could be due to the outcome causing the exposure rather than the exposure causing the outcome
140
What is meant by lead time bias
When screening identifies an outcome earlier than it would otherwise have been identified resulting in an apparent increase in survival time even if screening has no effect on outcome
141
What is meant by length time bias
A type of bias resulting from differences in the length of time taken for a condition to progress to severe effects that may affect the apparent efficacy of a screening method
142
What are the Bradford hill criteria for causality
1. Strength of association - magnitude of relative risk
2. Dose response - higher the exposure the higher the risk of disease
3. Consistency - similar results from different researchers using various study designs
4. Temporality - Does the exposure precede the outcome
5. Reversibility - Removal of the exposure reduces the risk of disease
6. Biological plausibility - biological mechanisms explain the link
7. coherence - logical consistency with other information
8. Analogy - similarity with other established cause-effect relationships
9. Specificity = relationship specific to outcome of interest
143
What does a descriptive study involve
1. Case reports or case series - study individuals
| 2. Ecological studies - use routinely collected data to show trends in data and thus useful for generating hypothesis
144
What is the issue with ecological studies
Shows prevalence and association but cannot show causation
145
What is a cross section study?
Divides the population in to those without the disease and those with the disease and collects data on them at defined times to find associations at that point in time - used to generate hypothesis but prone to bias and have no time reference
146
What are the advantages of across sectional study
Quick and cheap
Provides data on prevalence @ single time point
Large sample size
Good for surveillance and public health planning
147
What are the disadvantages of a cross sectional study
Risk of reverse causality (Don't know whether outcome or exposure came first)
Cannot measure incidence (Number of new cases)
Risk of recall bias and non-response
148
What is a case control study
A type of retrospective analytical study that takes people with a disease and matches them to people without the disease for age/sex/habit/class
Study previous exposure to the agent in question
Quick and inexpensive but retrospective nature only shows an association and date my be unreliable due to problems with patients memories
149
Give an example of a case control study
Researchers set out to examine the association between alcohol consumption and stroke - they identify all new patients admitted with stroke and compare their alcohol consumption with patients admitted for elective surgery
150
What are the advantage of a case control study
1. Good for rare outcomes (Cancer)
2. Quicker than cohort of intervention studies (As the outcome has already happened)
3. Can investigate multiple exposures
151
What are the disadvantages or case control studies
Difficulties finding controls to match with cases
Prone to selection and information bias
152
What is a cohort study
prospective study that starts with a population without a disease in question and study them over time to see if they are exposed to the agent in question and if they develop the disease in question or not
153
What are the advantages of a cohort study
Possible to distinguish preceding causes from concurrent associated factors
Lower chance of selection and recall bias
Absolute, relative and attributable risks can be determined
Prospective - so can show causation where retrospective can't
Good for common and multiple outcomes
154
What are the disadvantages of a cohort study
Requires a control group to establish causation
Takes a long time
Loss to follow-up (Drop out)
Need a large sample size
155
What is a randomised controlled trial
patients are randomised into groups and one group is given the intervention and the other is given a placebo/conrol and the outcome is measured
randomisation allows confounding to be equally distributed and biases minimalised
156
What are the advantages of a RCT
Low risk of bias and confounding
Can infer causality (Gold standard)
157
What are the disadvantages of an RCT
time consuming
Expensive
Volunteer bias
Specific inclusion/exclusion criteria meaning the study is different from typical patients
Ethical issues - is it ethical to withhold treatment that is strongly believed to be effective
158
What are the main issues with controlled trials that are not randomised?
Very subject to bias
Confounding factors are not equally spread across the groups
159
What is screening
A process which picks out apparently well people who are at risk of disease in hope of catching the disease at its early stages - NOT Diagnostic
160
What are the Wilson and Junger criteria for a screening programme?
1. Disease must be important
2. Disease must have a known detectable latent phase
3. Disease must have a known natural course/progression
4. Must be a test which is acceptable to the population
5. Must be a treatment for the disease
6. Must be an agreed at risk population of which to screen
7. Must be an agreed policy on who to treat
8. Costs of screening should be economically balanced
161
What are the different types of screening
(i) Population-based screening programmes (Cervical cancer, breast cancer)
(ii) Opportunistic screening (Performing BP measurements in the GP)
(iii) Screening for communicable disease
(iv) Pre-employment and occupational medicals
(v) Commercially provided screening (where you can pay to get your blood sent off and tested for genetic problems
(vi) Genetic counselling (Genetic testing for people with FHx of genetic disease)
162
What are some disadvantages of screening
1. Exposure of well individuals to distressing or harmful diagnostic tests
2. Detection and treatment of sub-clinical disease that would never have caused any problems
3. Preventative interventions that may cause harm to the individual or population
163
What is sensitivity of a screening test and how do you calculate it?
Proportion of people with the disease who are correctly identified by the screening test
True positive/ (True positive + False negative)
164
What is the specificity of screening and how is it calulated
Proportion of people without the disease that are correctly excluded by the screening test
True negative / (True negative + False positive)
165
What is the positive predicted value and how is it calculated
Proportion of people with a positive test result who actually have the disease
True positive/ (True positive + False positive)
166
What is the negative predicted value and how is it calculated
Proportion of people with a negative test who do not have the disease
True negative / (True negative + False positive)
167
What factors could contribute to the promotion of excessive energy intake
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Genetics
Employment (Shift work)
Early development factors
TV viewing and advertising
Characteristics of food (Energy density, macronutrient composition, satiety and satiation, portion size)
Reduced physical activity
Sleep
Environmental cues
Psychological factors
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168
Define malnutrition
Deficiencies, excesses or imbalances in a persons intake of energy and or nutrients
169
What are the two different types of malnutritions
1. Undernutrition
- Stunting (Low height for age)
- Wasting (Low weight or age)
- Underweight (Low weight for age)
- Macronutrient deficiencies or insufficiencies
2. Overweight
- Obesity
- Diet related non-communicable disease (Heart disease, stroke)
170
Name some chronic conditions requiring nutritional support
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Cancer
Cystic fibrosis
Coeliac disease
IBD
T1/2 DM
Failure to throve
Eating disorders
Overweight/Obesity
Sarcopenic obesity in elderly
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171
What are some of the early influences on feeding behaviour
1. Maternal diet - amniotic fluid is influenced by maternal diet and in utero environment influences taste exposure
2. Role of breast feeding for taste preference and bodyweight regulation
3. Parental practices
172
What are some of the parenting behaviours that can encourage eating
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Model healthful eating behaviours
Responsive feeding - recognising hunger and fullness cues
Providing a variety of foods
Avoiding pressure to eat
Restriction
Authoratative parenting
Not using food as a reward
Indulgent/neglectful feeding practice
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173
What is a non-organic feeding disorder?
High prevalence in children under 6
Characterised by feeding aversion, food refusal, food selectivity, fussy eaters, failure to advance to age appropriate foods, negative meal time interactions
174
What are the three main eating disorders
1. ANorexia nervosa
2. Bulimia nervosa
3. Binge eating disorder
175
Define eating disorder
Clinically meaningful behavioural or psychological pattern having to do with eating or weight that is associated with distress, disability or with substantially increased risk of morbidity or mortality
176
Define disordered eating
Restraint and strict dieting, disinhibition, emotional eating, binge eating, night eating, weight and shape concerns , innapropriate compensatory behaviours that do not warrant clinical diagnosis
177
What are the three forms of dieting
1. restrict the total amount go food eaten
2. Do not eat certain types of food
3. Avoid eating for long periods of time
178
What are the challenges of dieting
(i) RF for development of eating disorders in some individuals
(ii) Dieting results in loss of lean body mass not just fat mass
(iii) Dieting slows metabolic rate and energy expenditure
(iv) Chronic dieting may disrupt normal appetite responses and increase subjective sensations of hunger
(v) Long term weight loss is challenging – interventions typicall demonstrate weight loss, plateau then weight gain
(vi) Weight cycling (From repeated diet relapse) often leads to overshoot and may accelerate weight gain)
(vii) Non-obese dieters are at an increased risk of fat overshooting compared to obese dieters
