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Flashcards in SAQ Public Health Deck (68):
1


Ottawa Charter


1. Building healthy public policy
2. Creating supportive environments
3. Strengthening community action
4. Developing personal skills
5. Re-orientating health care services toward prevention of illness and promotion of health

2


The basic strategies for health promotion were prioritized as:

* Advocate: Health is a resource for social and developmental means, thus the dimensions that affect these factors must be changed to encourage health.
* Enable: Health equity must be reached where individuals must become empowered to control the determinants that affect their health, such that they are able to reach the highest attainable quality of life.
* Mediate: Health promotion cannot be achieved by the health sector alone; rather its success will depend on the collaboration of all sectors of government (social, economic, etc.) as well as independent organizations (media, industry, etc.).

3

Social Deprivation Index

1. Income
2. Employment
3. Communication (telephone access)
4. Transport
5. Support (single parent family)
6. Qualification
7. Living space
8. Owned home (people not living in own home

4

The Code of Rights gives you 10 rights. These are:

1. To be treated with respect.
2. To be treated fairly without pressure or discrimination.
3. The right to dignity and independence.
4. To receive a quality service and to be treated with
care and skill.
5. To be given information that you can understand in a way
that helps you communicate with the person providing the
service.
6. To be given the information you need to know about your
health or disability; the service being provided and the names
and roles of the staff; as well as information about any tests
and procedures you need and any test results.
In New Zealand, people are encouraged to ask questions and
to ask for more information to help them
understand what is going on.
7. To make your own decision about your care, and to
change your mind.
8. To have a support person with you at most times.
9. To have all these rights apply if you are asked to
take part in a research study or teaching session
for training staff.
10. The right to complain and have your complaint

5



1. Bradford Hill criteria


1. Strength: A small association does not mean that there is not a causal effect, though the larger the association, the more likely that it is causal.[1]

2. Consistency: Consistent findings observed by different persons in different places with different samples strengthens the likelihood of an effect.[1]

3. Specificity: Causation is likely if a very specific population at a specific site and disease with no other likely explanation. The more specific an association between a factor and an effect is, the bigger the probability of a causal relationship.[1]

4. Temporality: The effect has to occur after the cause (and if there is an expected delay between the cause and expected effect, then the effect must occur after that delay).[1]

5. Biological gradient: Greater exposure should generally lead to greater incidence of the effect. However, in some cases, the mere presence of the factor can trigger the effect. In other cases, an inverse proportion is observed: greater exposure leads to lower incidence.[1]

6. Plausibility: A plausible mechanism between cause and effect is helpful (but Hill noted that knowledge of the mechanism is limited by current knowledge).[1]

7. Coherence: Coherence between epidemiological and laboratory findings increases the likelihood of an effect. However, Hill noted that "... lack of such [laboratory] evidence cannot nullify the epidemiological effect on associations".[1]

8. Experiment: "Occasionally it is possible to appeal to experimental evidence".[1]

9. Analogy: The effect of similar factors may be considered.[1]

6




INFORMED CONSENT
should disclose and discuss with your patient:



1. The diagnosis as far as it is known

2. The nature and purpose of the proposed treatment or procedure

3. The risks and benefits of the proposed treatment or procedure

4. Alternatives to this treatment or procedure (regardless of their cost or availability in the New Zealand public health system)

5. Therisksandbenefitsofthealternativetreatmentorprocedureasfarasyouknowthem;and

6. The risks and benefits of not receiving or undergoing a treatment or procedure. The patient has the right to:

7. Consider the information given

8. Ask for clarification and ask for time to consider the information

9. Consult with family and others

10. Give consent or decline to give consent

11. Waive the right to discuss the details of treatment

12. After having given consent, change his or her mind and withdraw the consent.

7


Criteria for assessing screening programmes

1. The condition is a suitable candidate for screening.
2. There is a suitable test.
3. There is an effective and accessible treatment or intervention for the condition identified
through early detection.
4. There is high quality evidence, ideally from randomised controlled trials, that a screening
programme is effective in reducing mortality or morbidity.
5. The potential benefit from the screening programme should outweigh the potential physical and
psychological harm (caused by the test, diagnostic procedures and treatment).
6. The health care system will be capable of supporting all necessary elements of the screening
pathway, including diagnosis, follow-up and programme evaluation.
7. There is consideration of social and ethical issues.
8. There is consideration of cost-benefit issues.

8

Outbreak Investigation and Management

1. Prepare for field work
2. Establish the existence of an outbreak
3. Verify the diagnosis
4. Define and identify cases
5. Describe and orient the data in terms of time, place, and person
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine hypotheses and carry out additional studies
9. Implement control and prevention measures
10. Communicate findings

9




The Treaty and health

The Government has identified three principles derived from the Treaty and relevant to Māori health in key statements and policies.2
The principles are:

Partnership — working with Māori communities at all levels to develop strategies for the community’s health care,

Participation — involving Māori at all levels of the planning and delivery of health care services, and

Protection — working to ensure that Māori have at least the same level of health as non- Māori, and safeguarding Māori cultural concepts, values, and practices.3


The Treaty of Waitangi can be seen to apply to Māori health in numerous ways.

10

1. Briefly outline your approach to the initial investigation and confirmation of this possible outbreak. (8 marks)



1. Confirm details of the cases (including results of diagnostic testing, if done).

2. Confirm existence of an outbreak (by comparison with numbers of cases expected from surveillance data). In this case, the link to the function makes it likely there is an outbreak.

3. Case finding. Not all cases will have been notified as many may not have seen their doctor. If a list of attendees is available form the organisers then this can be used for case finding.

4. Establish a case definition. Will usually have “suspected” (based on symptom cluster) and “confirmed” (based on symptoms plus laboratory confirmation) cases.

5. Document the details of all cases: time of onset of illness, age. sex, foods eaten, other exposures e.g. water. This, along with the epidemic curve may allow you to hypothesise about possible sources for the outbreak.

6. Construct an epidemic curve with this TIME, PLACE & PERSON information. This will give clues to incubation period (and possibly help identify organism) and whether or not outbreak is point-source (as you might suspect in this case).

7. Initial investigation of those catering the event and the site. Where any of the food handlers ill? If they still are, they should cease involvement in food preparation until well. How was the food prepared, stored and served? How long was food kept after cooking or preparation before it was served? What was the overall hygiene of the food preparation and serving areas like? If there are obvious breaches of food hygiene, these should be remedied immediately. Unless these are extreme, the kitchen may not have to be closed while this is done.
8. Take food samples (if available) for bacterial testing (NB. Viral testing is seldom done unless bacterial testing is negative and/or the characteristics of the outbreak suggest a viral cause like Norwalk agent). After 72 hours or more, there may be no foods left to sample.
9. You could also include making sure that cases received appropriate treatment (usually supportive, rather than antibiotics for gastro) and advice about hand-washing after using the toilet etc

11

OUTBREAK
2. Your initial inquiries revealed that at least 70 people became ill after the function. What conclusions can you draw from Figure 1 below about the nature of this outbreak and the illness causing it? (2 marks)

The epidemic curve shows a classic “point-source” pattern with a sharp rise in numbers of cases which tails away over 72 hours. The incubation period for the illness is mostly between and 9-24 hours (median is 24 hours). There is one case before 0 hours and this person may have been already ill at the time of the function (perhaps they were a food handler). There is a debatable smaller peak of cases at 41-56 hours, but it is not the classical bi-modal appearance of a point-source outbreak followed by person to person transmission that is sometimes seen in outbreaks of gastro.

12

OUTBREAK
What type of epidemiological study would you carry out to further investigate the source of this outbreak? Briefly outline how you would go about carrying out such a study. (7 marks)

This part of the question refers to the type of analytical study you might carry out to test the hypotheses about the source of the outbreak that you have come up with from your initial descriptive investigation. There are really only two choices here: a case-control study or a retrospective cohort study. In this case, if it is possible to identify all those who attended the function, you could use the cohort design. The cohort would consist of all those who attended the function, with the cases being those who became ill and the rest who did not acting as controls. All the guests would be asked a series of questions including their demographic details and details of exposure to the range of foods served at the function. If the caterers have a menu, this can be used to help construct the questionnaire. They should also be asked about other exposures related to gastroenteritis (e.g. contact with sick person, water consumption, swimming etc) as appropriate. In this case, for example, Salmonella is most likely to be food-borne, rather than water-borne, whereas Campylobacter could be either. You would then compare the proportions exposed to the particular foods in the cases and the controls and calculate relative risks (or odds ratios for a case-control study) for each food/exposure. Some exposure may have high and significant RRs. Very often, more than one exposure may be associated with an increased RR. This may be because the foods were served or stored together (cross-contamination) or because they were consumed together e.g. pavlova and cream, but only one was contaminated, leading to the apparent association.

13

OUTBREAK
5. Discuss the measures that might be put into place to prevent another outbreak of this type. (4 marks)

• Reiterate the importance of hand washing as a basic food safety measure for food handlers and consumers.
• Put in place food safety training for the catering group. Advice may have to be provided in languages other than English. The help of elders or ministers (or other respected members of the community group) may be enlisted to reach the community. The provision of food to guests at large gatherings is a common practice in many cultures represented in the South Auckland region and most of these functions are self-catered, though some community venues have facilities as large as many commercial kitchens.
• Ensure that umu are prepared properly and foods cooked for a sufficient length of time before serving. There are guidelines about this available from public health services.
• Provide advice to the general public about safe food handling and within the local community link this to the outbreak to illustrate its importance.
• May also enhance surveillance in the area by informing GPs about this outbreak to encourage reporting of suspect gastroenteritis.
• Maintain liaison with the local authority as they have role in inspection of food premises.

14

Describe a table showing the effect of screening on 5 year survival rate

Table 1 shows 5-year survival in people with lung cancer diagnoses as a result of screening compared with people diagnosed as a result of signs and/or symptoms. The 5-year survival for people diagnosed by screening is 35% and the 5-year survival for people diagnosed as a result of signs and/or symptoms is 19%. A higher percentage of people diagnosed with lung cancer by screening live for five years after diagnosis than people diagnosed symptomatically. The p value is 0.004, so this difference is highly unlikely to be due to chance.

15

Bias associated with screening

These results should not be used to infer that screening will extend the lives of those diagnosed with lung cancer. This is because a comparison of survival could be affected by lead-time, length, overdiagnosis, and selection biases. The effect of these biases is outlined below:

Lead time bias
Screening advances the date of diagnosis and thereby extends the interval between diagnosis and death even if the time of death is unchanged. People whose lung cancer was detected by screening will appear to have longer survival than people diagnosed in the normal way.

Length bias
Fast growing lung tumours will progress rapidly through the preclinical phase and will therefore be less likely to be detected by screening. Screening at infrequent intervals will therefore detect a disproportionate number of slow growing tumours with a good prognosis.

Selection bias
People who take up the offer of screening may differ in their underlying risk of lung cancer and/or mortality from lung cancer so that their prognosis would have differed from non participants even in the absence of screening.

Overdiagnosis bias
Screening may detect lung abnormalities that are of questionable malignancy and would not have been diagnosed in the absence of screening.

16

Lead time bias

Screening advances the date of diagnosis and thereby extends the interval between diagnosis and death even if the time of death is unchanged. People whose lung cancer was detected by screening will appear to have longer survival than people diagnosed in the normal way.

17

Length bias

Fast growing lung tumours will progress rapidly through the preclinical phase and will therefore be less likely to be detected by screening. Screening at infrequent intervals will therefore detect a disproportionate number of slow growing tumours with a good prognosis.

18

Selection bias

People who take up the offer of screening may differ in their underlying risk of lung cancer and/or mortality from lung cancer so that their prognosis would have differed from non participants even in the absence of screening.

19

Overdiagnosis bias

Screening may detect lung abnormalities that are of questionable malignancy and would not have been diagnosed in the absence of screening.

20

How to design a RCT?

The only study design that is not affected by these biases is a randomised controlled trial using an intention to treat analysis, with mortality as the outcome measure. The RCT would require ethics committee approval and written informed consent from participants. Power and sample size calculations would be required to ensure that the trial included adequate numbers to detect a statistically significant a clinically relevant reduction in lung cancer mortality if one exists. People at high risk of lung cancer would be identified. For instance, criteria for “high risk” might be that people had smoked more than 10 cigarettes per day for ten or more years. Such individuals could be approached by their GPs and invited to participate.

Participants would be randomly allocated to an intervention group and a control group. The groups would be compared at baseline to ensure that randomisation had created two similar groups (thereby controlling for confounding). Those in the intervention group would be offered annual chest x-rays and sputum cytology. Those in the control group would be offered their regular medical care. People in both groups would be followed up and deaths from lung cancer would be recorded. The lung cancer mortality rate would be calculated for each group and a relative risk and 95% confidence interval could be calculated.

An intention to treat analysis would be used (people would be analysed in the groups to which they had been randomised, even if some people in the intervention group had not received screening and some people in the control group had). This avoids selection bias (since people who accept an offer of screening may differ from those who do not) and maintains control of confounding. Because the outcome measure is lung cancer mortality, lead-time bias would not affect the RR (mortality is measured independently of the time of diagnosis, unlike survival which is measured from the time of diagnosis until death). Similarly, overdiagnosis bias should not affect a comparison of mortality (since deaths from lung cancer rather than incidence or survival, are being measured). This is important since there is evidence that overdiagnosis of lung cancer can occur as a result of screening.1-2 Length bias would not affect the results of the RCT because the comparison is between a group offered screening and a similar group not offered screening (rather than a comparison between those diagnosed by screening and those diagnosed symptomatically). This means that people with fast-growing tumours are still included in the intervention group even if their lung cancer was missed by screening and diagnosed symptomatically.

21

The reasons for carrying out an evaluation of a new programme are

• To find out whether the programme is needed, whether its objectives are reasonable, and if so, how best to implement the programme (literature review and formative evaluation)
• To document what the programme involves (so that if can be replicated elsewhere if necessary), and to assess the acceptability, resource requirements, sustainability and economic efficiency of the programme (process evaluation)
• To see if the programme can achieve its stated objectives (outcome evaluation) RCT the best

22

How to describe OR

Table 1 shows odds ratios and 95% confidence intervals for risk factors for meningococcal disease in this study. The odds ratios are adjusted for all the exposures listed in the table, and also for parental home ownership and meningococcal disease season.

In this study cases were 88% less likely than controls to have been vaccinated against serogroup C meningococci, with an odds ratio of 0.12, and a 95% confidence interval of 0.04 to 0.37. This 95% confidence interval did not include 1.0 so the result is statistically significant.

Cases were nearly four times as likely as controls to have had multiple intimate kissing contacts, with an odds ratio of 3.7, and a 95% confidence interval of 1.7 to 8.1. This 95% confidence interval did not include 1.0 so the result is statistically significant.

Cases were 3.4 times as likely as controls to be university students rather than being employed, with an odds ratio of 3.4, and a 95% confidence interval of 1.2 to 10.0. This 95% confidence interval did not include 1.0 so the result is statistically significant (although it is quite wide, meaning that the estimate of the odds ratio is imprecise).

Cases were 3.3 times as likely as controls to be school students rather than being employed, with an odds ratio of 3.3, and a 95% confidence interval of 0.8 to 13.4. This 95% confidence interval includes 1.0 so the result is not statistically significant (this result may have occurred by chance).

23

Confounding factor

To be a confounding factor, the factor must be independently linked to the exposure of interest and also to the outcome of interest, and the factor should not be a factor in the causal pathway between exposure and outcome.

24


Methods to reduce bias in Case control study

Selection bias:
Strict case definition (to avoid wrongly selecting non-cases into the case group). Controls should represent the population from which the cases came. Methods to ensure a high response rate from both cases and controls would be required.

Information bias:
Information should be collected in exactly the same way from the cases and the controls (to avoid introducing differences). Ideally interviewers should be blinded to the case or control status of the participants. This may not always be possible, especially if some cases are too unwell to be interviewed. Recall bias is a potential problem in case-control studies, and could be addressed by setting a reference date for controls (so they are asked to recall events for a similar time period to cases), and by using other sources to verify data.

Confounding
Data on potential confounding factors would need to be collected (in the study questionnaires, and possibly verified from other sources such as medical records). These factors would need to be adjusted for in the analysis. Stratification could be used initially (to identify effect modification), and multivariate methods used to provide adjusted odds ratios.

25


Advantages of case-control method


Case-control studies are relatively cheap and quick (because case-control studies usually require smaller numbers of participants than longitudinal studies, and with this design there is no need to wait for the disease to develop). This is important in the investigation of an outbreak of disease.

Case-control studies are good for investigating rare diseases. Meningococcal disease is not particularly common. A cohort study or intervention study of a rare disease would require many participants in order to include enough people who might develop the disease.

Case-control studies can be exploratory (more than one exposure can be investigated in the same study). In this study, several exposures (relevant to meningococcal disease, such as overcrowding, sharing drinking bottles, and other behaviours) could be investigated.

Case-control studies are analytical, so can be used to test hypotheses.

26


Disadvantages of case‑control method

Case-control studies are more prone to bias (see study design section above).

Because information about exposure is collected after the onset of disease, there may be problems in assessing the time sequence between an exposure and an outcome (which makes it more difficult to determine causation). In this situation the time-sequence is likely to be reasonably clear.

There may be problems with confounding. Randomisation is not an option in a case-control study, so there is always the possibility of confounding by unidentified confounding factors (which could not be adjusted for in the analysis).

Case-control studies can only assess one outcome (unlike cohort studies which can assess several outcomes). In this study only meningococcal disease can be assessed as an outcome. This is appropriate since meningococcal disease is the disease of interest.

There is no direct measure of risk (unless a population-based case-control study is carried out). The odds ratio is calculated as an estimate of the relative risk.

27

New program Ethical principles


Individual autonomy
Some individuals do not wish to consume fluoridated water. If the Christchurch water supply is fluoridated, these people’s autonomy could be infringed, and they may have to access their drinking water from alternative sources (for instance bottled water). Because fluoridation affects everyone in the area of the water supply, irrespective of whether they agree with fluoridation, (and because not all parents can afford the option of buying bottled water) it may be regarded as an infringement of parents’ right to decide for their children about fluoridation. For comments on children’s rights see section on “justice” below.

Beneficence
This is the concept of “doing good”. There is evidence that fluoridation of water supplies reduces the risk of dental decay in children. Children with severe dental decay experience pain and distress, and often cannot eat properly, with resultant adverse effects on their growth and development. Some children in Christchurch have had to have deciduous teeth extracted due to severe decay. Children could benefit because fluoridation is likely to reduce these problems.

Nonmaleficence
Avoiding harm means avoiding any risks associated with fluoridation. There is not good evidence that fluoridation will be harmful to people’s health and wellbeing.

Justice
Because fluoridation is available to all who drink from the fluoridated water supply, all people are treated fairly, and thus all are afforded protection against dental decay. It also means that potentially children can receive the benefits of fluoridation even if their parents don’t necessarily agree with fluoridating water supplies.

At present, there is evidence that Maori and Pacific Island children in Christchurch are at greater risk of dental decay than are non-Maori, non-Pacific children. This may be because these children have less access to fluoride in other forms (for instance, in toothpaste). If so, fluoridation of the water supply may reduce the risk of dental decay in these children, and thus reduce the disparity between ethnic groups.

Utility
This is concerned with obtaining “the greatest good for the greatest number”. Thus, when an intervention is known to reduce the risk of disease in a community, and is not harmful, the onus is on public health practitioners to protect the health of the community. Sometimes public health interventions (such as fluoridation, notification of communicable diseases, or immunisation) cause tensions between individual autonomy and utility.

28


What are some key factors that your research team would need to consider in terms of Maori participants and participation within this specific research project?

Suggest some solutions to these factors.

* Define who might be the relevant Maori community. Use key liase person, establish a relationship with them discuss current barriers within the research design. Use Maori professional in area, not just ‘a’ Maori.
* Clearly define who your Maori participants will be (ethnicity question).
* Go over current methodological approach with the Maori liase person/researcher and discuss applicability of design and how it might lead to mis-understandings by participants, or what particular responses might mean within a Maori cultural context.
* Understand the context of suicide within Maori health frameworks.
* Bring on board a Maori health researcher.
* Perhaps look at a team being developed to specifically focus on Maori health data, which would allow a fuller consultation within the community.
* Highlight the need to practice a level of cultural competence within the research, work to support those participants who have identified as Maori, and allow their data to be respected within that context.
* Discuss possible dissemination processes.

29


How would your research team measure its effectiveness in terms of cultural competence when working alongside Maori participants, and the Maori data?

Looking for:

* Engagement with the Maori community’ and hui and in terms of support letters.
* The involvement of Maori health researchers or a Maori research unit.
* Recruitment and retention of Maori participants high throughout the study.
* Participants feedback around how they found the process
* Ability to contribute to better understanding of Maori and suicide.
* That the Maori data is framed in a way that captures Maori beliefs, values and experiences.
* That the analysis is able to capture within it the social reality of Maori e.g. socio-economic impacts, housing, access to care and services, racism etc.

30


The four main types of economic evaluation are:

cost minimisation analysis; cost-effectiveness analysis; cost-utility analysis and cost benefit analysis. They differ mainly in the way in which benefits or health effects are valued.

31


Cost minimisation analysis

Cost minimisation analysis simply aims to identify the lowest cost option for providing a service. The health outcomes of different policy options are assumed to be the same and the main focus is on measuring the costs to find which option is the cheapest. There is no particular focus on valuing health outcomes, although it would be standard practice to state the types and volumes of health services provided.

Costs include staffing costs, supplies, expenses, as well as the costs of building space, heating, lighting etc.

32

Build healthy public policy:

eg. reduce legal blood alcohol limit for drivers and enhance enforcement (affects all, not just males and Maori but males over-represented in alcohol-related fatal traffic crashes). Increase excise tax on high alcohol beverages/decrease excise on low alcohol beer (the latter is the case in Australia where light beer accounts for 40% of all beer consumption). Stronger regulatory controls on alcohol advertising and sponsorship, particularly where this targets Maori (eg. sports popular with Maori)

33

Create supportive environments:

eg. promote social environments for young males where responsible alcohol consumption is encouraged and harmful consumption is not socially acceptable, for example in sports clubs, use the “Get into it, not out of it” message. Marae-based alcohol policies which support responsible drinking and alcohol reduction could also assist. Use of relevant and appropriate role models in social marketing.

34

Strengthen community action:

eg. support community initiatives such as YATA groups that take community approaches to address youth alcohol issues, support NGOs like ALAC to provide community education in alcohol harm reduction. Involve local communities and iwi in developing community alcohol harm reduction measures and provide resources to support and evaluate these.

35


Develop personal skills:

eg. community education in alcohol harm reduction (eg. “say when” campaign),encourage greater awareness of safe drinking limits and alcohol content of drinks, targeted campaigns for particular risk groups, such as young men and Maori.

36

Reorient health services:

eg. improve availability and accessibility of treatment services for problem drinkers and provide kaupapa Maori service options. Educate health professionals to ask patients about their alcohol consumption using appropriate screening tools and provide training in brief intervention for alcohol problems. Increase awareness of the particular burden of disease related to alcohol among Maori. Increase research into effective interventions for alcohol related harm and also research to better understand the social and environmental context of alcohol use behaviours.

37

Cohort
Advantages

1. A cohort study allows multiple outcomes to be assessed. For example, birth weight could be assessed in a cohort study as well as pre-term delivery.

2. Because a cohort study is prospective, the time sequence would be clearer than in a retrospective study such as a case-control study. This is important in assessing causation.

3. Because exposure (in this case alcohol consumption) is assessed prior to outcome (pre-term delivery), the likelihood of bias (for instance recall bias) is reduced in a cohort study.

4. It is possible to calculate risks (for instance, it would be possible to calculate the absolute risk of pre-term delivery in women who had consumed alcohol during pregnancy, as well as the absolute risk in women who had not consumed alcohol). The relative risk can then be calculated directly, rather than being estimated by an odds ratio.

38

Limitations
Cohort




1. A cohort study can be time consuming and expensive (compared with a case-control study).

2. Cohort studies usually involve a larger number of participants, and these people have to be followed up so that the outcomes can be measured.

3. Loss to follow up is a potential problem in a cohort study since this can introduce bias. In this study however, the follow-up period was relatively short, which meant this study could be completed more rapidly than many cohort studies and was probably less vulnerable to loss to follow up (since the women only had to be followed up for a few months).

4. Cohort studies (as with all observational studies) cannot control for confounding by unidentified confounding factors, since randomisation is not an option in an observational study.

5. A cohort study would not be appropriate for the investigation of rare diseases or outcomes.

39

There are several possible reasons for differences between studies:

Chance
A study may have had inadequate sample size to demonstrate an effect. Only a relatively small number (119) of women in this study had consumed 7 or more drinks per day during pregnancy. The other studies may have included larger numbers of women.

Bias
Bias can affect different studies in different ways. For instance, the previous studies may have been affected by bias leading to an overestimate of the effect of alcohol consumption on pre-term delivery, or alternatively bias in this study may have caused any association to be underestimated. The types of studies being compared should be considered when results differ between studies (for instance case-control studies are more vulnerable to recall bias than cohort studies).

Confounding
This study may have controlled better for confounding than previous studies (or not controlled as well), leading to a difference in results between studies. Some studies are less vulnerable to confounding than others, so the types of study should be considered (for instance, more weight would be given to the results of a RCT than an observational study).

Causation
There may be a real difference between the populations included in the different studies, leading to different results (although for this particular example this explanation seems unlikely).

40

A nested case control study has several advantages over an ordinary case-control study.

Firstly, a nested case-control study is less vulnerable to selection bias, since you know that the controls represent the population from which the cases came (because they are from the same cohort as the cases).
In a cohort study, information (including blood samples) is collected before the disease develops. This means that, unlike most case-control studies, nested case-control studies can avoid recall bias, because they have access to information that had been collected before the cases developed the disease.
Lastly, in this example, it was important to test blood samples that had been collected before the onset of disease, to ensure that the time sequence was correct. Ordinary case-control studies had also found increased EBV IgG levels in people with MS compared with controls, but there had been some concern that the disease process may have affected the immune system to cause increased IgG levels, rather than the other way round.

41

(a) Explain why population-based approaches rather than individual approaches are required to address overweight and obesity.

o reach large numbers/prevalence of overweight and obese (individual/medical approaches don’t have capacity for large numbers)
o address issue in cost-effective strategy
o impact on lifestyle issue with both structural and behavioural approaches
o use ‘prevention paradox’ – small change in BMI across a population will have large impact on obesity in tail

42

(b) Discuss why the Ottawa Charter is a useful framework for addressing overweight and obesity.

Ottawa Charter is foundation health promotion document providing strategies and actions to use health promotion approach. Useful framework because:
o Ensures a comprehensive array of strategies
o Emphasises both structural and behavioural approaches
o Provides direction to targets populations and subgroups at greatest risk
o Seeks community action to implement change
o Works at all levels of society: societal, organisational, community and individual

43

Healthy Public Policy eg

Legislation
Fat/sugar tax
Subsidise healthy foods eg fruit and vege – could be removal of GST
Regulation of food labels/content
Policy regarding canteen foods
Policy regarding time for physical activity (PA)
Removal of cars from pedestrian/cycle areas

44

Creating Supportive Environments (physical and social – eg

making the healthy choice the easy one)
Food available from canteen eg low-fat alternatives
Safe/aesthetic environment for PA eg bike riding
Workplace showers/bike lock up
Low-fat/PA are norm supported by society

45

Develop Community Action eg

Support grass roots groups to be advocates to their community
Encourage Marae/churches to take ownership of message
Seek support/promotion from community leaders/role models
Competitions that engage communities

46

Develop Personal Skills eg

Training and education opportunities eg cooking class
Social marketing via media
School-based programs

47

Reorient Health Services eg

Get primary care to ask questions about nutrition/PA
Get primary care to recommend nutrition/PA
Get primary care to refer to providers of nutrition/PA eg green prescription
Get hospital services and specialists (eg cardiac surgeons) to take similar approaches to primary care

48

Describe RCT

1. In a randomised controlled trial, participants are randomly allocated to the intervention and control groups. This reduces the likelihood of selection bias (since neither participants nor investigators can choose which group an individual participant will be in).

2. Although not all the women in the intervention group necessarily accepted and practiced the BSE intervention, the use of an intention to treat analysis means that selection bias could not affect the analysis of the outcome.

3. An intention to treat analysis could result in an underestimation of the effect of BSE however (for instance if a high proportion of women in the control group did not practice BSE, or only performed BSE intermittently). In an effort to avoid this, the women in the intervention group were carefully trained, their technique was assessed, and they received reminders to practice BSE.

4. A randomised controlled trial, with breast cancer mortality as the outcome, is the appropriate design to control for the biases that particularly affect studies of the efficacy of screening (selection bias, lead-time bias, overdiagnosis bias, and length bias).

5.Because the individuals making the judgements about cause of death were blinded, information bias should not have affected the comparison of the outcome (breast cancer mortality) between the groups.

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What suggestions would you make to the research team about engaging with the relevant Maori community to ensure this data is analysed adequately and the findings addressed?



Suggest some solutions to these factors.

* Define who might be the relevant Maori community. Use key liase person, establish a relationship with them discuss current barriers within the research design. Use Maori professional in area, not just ‘a’ Maori.
* Clearly define who your Maori participants will be (ethnicity question).
* Go over current methodological approach with the Maori liase person/researcher and discuss applicability of design and how it might lead to mis-understandings by participants, or what particular responses might mean within a Maori cultural context.
* Understand the context of suicide within Maori health frameworks.
* Bring on board a Maori health researcher.
* Perhaps look at a team being developed to specifically focus on Maori health data, which would allow a fuller consultation within the community.
* Highlight the need to practice a level of cultural competence within the research, work to support those participants who have identified as Maori, and allow their data to be respected within that context.
* Discuss possible dissemination processes.

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How would your research team measure its effectiveness in terms of cultural competence when working alongside Maori participants, and the Maori data?

Looking for:

* Engagement with the Maori community’ and hui and in terms of support letters.
* The involvement of Maori health researchers or a Maori research unit.
* Recruitment and retention of Maori participants high throughout the study.
* Participants feedback around how they found the process
* Ability to contribute to better understanding of Maori and suicide.
* That the Maori data is framed in a way that captures Maori beliefs, values and experiences.
* That the analysis is able to capture within it the social reality of Maori e.g. socio-economic impacts, housing, access to care and services, racism etc.

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The NZDep=

an area based measure of deprivation (dep 10 is the most deprived). Derived using 9 variables such as income, owned home, employment, qualifications etc from the census- developed by health researchers.

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Should the patient be allowed to refuse ECT, or should this be overridden? Principal legal and ethical considerations.

Ethical:
Primum non nocere. Would ECT cause her more harm. Or would not giving ECT cause her more harm?

1. Beneficence. Is it in the best interest of the patient to continue ECT? Can we advise some reasonable alternatives. See autonomy re her ability to contribute to decisions. If she is not able, then we have to act in her best interest.
2. Non-Maleficence. We can’t give ECT out of some kind of perverse interest in causing harm, or because we are interested in researching ECT or whatever.
3. Autonomy. She must be respected in her refusal of treatment unless there is some issue of competence. See Legal for further.
4. Dignity. Closely related to autonomy. Respect for the rights and wishes of the patient. Even if compelled to have ECT, she still has the right to dignity. Means that we cannot treat her as incompetent unless she is proven to be.
5. Justice. There are various kinds. Distributive; is she the most needy? Would she be taking resources away from more needy patients… Legal. Can we legally compel her to take the therapy? OR are we allowed to let her not take it. Is there a court order. See legal.
6. Confidentiality. Respect for her privacy whatever the decision.
7. Honesty. We must ensure that she understands all the risks and benefits of the treatment or its refusal. Not just our personal views, but evidence based and made understandable for her.
8. Equality/equity. She has to be treated in the same or equivalent manner as any other patient.

Legal:
Main legislations:
NZBORA (Bill of Rights Act 1990)
Everyone has the right to refuse Medical Treatment.
NZMHCTA (Mental Health Compulsory Treatment Act 1999)
Section 40 Committal
Is she under the Act? If so, what are the orders?
Is she of legal age?
Is she legally competent. Assumption must be yes.
Have the legal requirements of the Health and Disabilities Act been fulfilled with regard to informed consent.

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b. TOP regulations in NZ –

<12 weeks + 2 referrals from certified consultants

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Capacity factors

Communicate choice;
Understand relevant information;
Manipulate information; and
Appreciate the situation and its consequences.

A person may be able to communicate, understand and manipulate information but not to appreciate the consequences of decisions.

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Medical conditions that affect capacity

Dementia – memory or frontal lobe impairment
Delirium
Head injury
Depression, anxiety or psychosis
Sensory impairment
Intellectual disability

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Triggers for capacity assessment


Refusal to consent

Proxy appointed – welfare guardian or EPOA

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The Protection of Personal and Property Rights Act 1988

The purpose of the PPPR Act is to assist an adult who, because of incapacity is not able to make or communicate decisions or manage their affairs

Enduring Power of Attorney (EPOA)
Welfare Guardian (Court order)

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Consent and Health Law in NZ

Health and Disability Commissioner’s Act 1994
Code of Health and Disability Services Consumers Rights 1996 (Code of Rights)
Protection of Personal and Property Rights Act 1988
New Zealand Bill of Rights Act 1990
Mental Health (Compulsory Assessment and Treatment) Act 1992
Human Rights Act 1993
Privacy Act 1993 (Health Information Privacy Code 1994)
Accident Compensation Act 2001
Human Tissue Act 2008

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Enduring Power of Attorney

A person decides in advance who can make decision for them if they become mentally incapable (EPOA)
Attorney “steps in the shoes” of person
Personal care and welfare or property or both

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If person lacks capacity and no EPOA or welfare guardian

Personal order from Family Court (“one-off”) for arrangements of person’s care, medical treatment or entitlement to services
Right 7(4) may apply but short term solution and cannot be used for on-going care and treatment decisions.

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The Contraception, Sterilisation and Abortion Act 1977c

need 2 certifying consultants and counselling

In NZ, age at which Informed consent can be given for all health issues is 16, EXCEPT if it involves women making decisions regarding reproduction issues (contraception, TOP) – They are deemed able to give consent at any age and their opinion is valid no matter how young they are

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Establish she is dead:

No response to stimuli
Absent carotid pulse
Absent heart sounds
Absent respirations
Fixed dilated pupils

What is your next action:
Inform son she is dead and offer condolences
He informs you she wishes to be cremated and this is confirmed by rest home staff.

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The Coroners Act 2006
Deaths that MUST be reported to the Coroner

If a Doctor is unable or unwilling to issue Cause of Death Certificate; and /or
Happened during a procedure; or
After the deceased had undergone surgery; or
As result of accident /unnatural cause/violence; or
Maternal (childbirth; pregnancy; postpartum); or
Person under custody or care; or
Suicide.

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Main arguments in support of voluntary euthanasia


* · Autonomy and the right to die;

* · Gives the person the choice of avoiding pain and distress;

* · Gives the person a choice of avoiding loss of dignity.

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Arguments against voluntary euthanasia



* · Hazards of voluntary euthanasia in practice (e.g. problems of the request, people's views may fluctuate, pressure from family);

* · Life belongs to God;

* · The intrinsic value of life;

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Care of dying patient

•Ensure symptoms are well controlled
•Stop unnecessary medication except those needed for symptom control
•Administer meds via syringe driver if unable to take orally
•Inform, update and support the family
•Listen to fears and concerns carefully with appropriate follow up support
•Answer questions honestly, if you don’t know - find someone who does
•Dying is unavoidable - but dying in pain and distress is.
•Uncertainty is created by how, when and where a person will die
•Treat the patient andfamily as the unit of care
An organised, consistent and personalisedapproach will help the person achieve what they would consider to be a ‘good death’

Support Services:
•Inpatient – Hospital Palliative Care Advisory Service
•Community – OtagoCommunity Hospice

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12 principles of the Privacy Act.

From the point of view of a health agency, the rules in the code can be summarised:

1. Only collect health information if you really need it.
2. Get it straight from the people concerned where possible.
3. Tell them what you're going to do with it.
4. Be considerate when you're getting it.
5. Take care of it once you've got it.
6. People can see their health information if they want to.
7. They can correct it if it's wrong.
8. Make sure health information is correct before you use it.
9. Get rid of it when you're done with it.
10. Use it for the purpose you got it.
11. Only disclose it if you have a good reason.
12. Only assign unique identifiers where permitted.

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How to minimize confounding

* matching

* randomisation

* standardisation




* stratification

* multivariate analyses

* restriction