Population health Flashcards

1
Q

What is the definition of public health?

A

“The science and art of preventing disease, prolonging life and promoting, protecting and improving health through the organised efforts of society

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the definition of population health?

A

The health outcomes of a group of individuals, including the distribution of such outcomes within the group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is primary health care? What does it include?

A

Universally accessible, scientifically sound, first level care provided by a suitably trained workforce. Gives priority to those most in need, maximises community and individual self-reliance and participation. Collaborates with other sectors.

e.g. GP’s

It includes: care of the sick, health promo and illness prevention, advocacy, and communtiy development.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is global health?

A

The health of populations in a global context which trascends the perspectives and concerns of individual nations.

e.g. eradicating smallpox.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Planetary health?

A

The health of humanity embedded in the context of human systems; ecosystems, political, economic, and social that shape the future of humanity and the Earth’s natural systems which define the safe environmental limits withing which humanity can flourish

“Far-reaching changes to the structure and fx of Earth’s natural systems represent a growing threat to human health… By unsustainably exploiting nature’s resources, human civilisation has flourished but now risks substantial health effects from the degradation of nature’s life support systems in the future.”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Ecohealth?

A

Conceptualisation and understanding health in its wider environmental or ecosystem context, within a globalising world.

Includes our ecology; our skin gut saliva, our own ecosystems.

Particuarly inportant in Indigenous culture; “Country’s health is our health”.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Onehealth?

A

“Worldwide strategy for expanding interdisciplinary collaborations and communications in all aspects of health care for humans, animals and the environment.”

Something between Ecohealth and Global health; particuarly focusing on emerging infectious diseases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the aim of intention to treat analysis in a clinical trial?

A

Reduce selection bias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Primary prevention reduces ____

A

reduces the likelihood of the development of a disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Secondary prevention _____

A

prevents or minimises the progress of a disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Tertiary prevention reduces _____

A

reduces progression of damage already done

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is rate of a disease development calculated?

A

(new cases) / (total person time of follow up)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Primary, secondary or tertiary prevention reduces the likelihood of the development of a disease?

A

Primary prevention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Primary, secondary or tertiary prevention reduces progression of damage already done

A

Tertiary prevention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is relative risk calculated?

What does it tell you?

A

(Risk exposed) / (Risk unexposed)

Re/Ru

indicates the relative magnitude of change in risk/rate of outcome, associated with exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Primary, secondary or tertiary prevention prevents or minimises the progress of a disease?

A

Secondary prevention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the aim of blinding in a clinical trial?

A

Reduce information/observor bias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is attributable risk percentage calculated?

What does it tell you?

A

AR% = (Re - Ru)/Re x 100

Proportion of incident disease among exposed people that is due to exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the aim of randomisation in a clinical trial?

A

Reduce influence of confounding variables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is risk calculated?

A

(Number of new cases in a defined period) / (population at risk)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is attributable risk calculated?

What does it tell you?

A

(Risk exposed) - (risk unexposed)

Ru-Re

indicates the absolute magnitude of change in risk/rate of outcome, associated with exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the “downside”(conservative measure) of intention to treat analysis in a clinical trial?

A

Underestimates treatment effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is population attributable risk percentage calculated?

What does it tell you?

A

100 x (Rt-Ru)/Rt

Proportion of incident disease among whole population that is due to exposure.

Rt= risk in the whole population which includes both exposed and unexposed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How is population attributable risk calculated?

A

(Rate in whole population) - (Ru)

Rt-Ru

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 3 essentail features of a clinical trial?

A

Randomisation

Blinding (aka masking)

Intention-to-treat analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 9 Bradford Hill Criteria for causality?

A

temporal relationship

strength
dose-response relationship
consistency
plausibility
exclude alternatives
experimental evidence
specificity
coherence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How is NNT calculated?

A

1 / (absolute rate/risk reduction)

1/ARR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How is sensitivity calculated?

A

True positive

True pos + False Neg

e.g. number of pregnant ladies who peed on the stick and got a positive results, over TP + FN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is positive predictive value calculated?

A

True positive

True pos + False Pos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How is specificity calculated?

A

True negative

True neg + False pos

Specificity of a test is the proportion of healthy patients known not to have the disease, who will test negative for it. Mathematically, this can also be written as: A positive result in a test with high specificity is useful for ruling in disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is negative predictive value calculated?

A

True negative

True neg + False Neg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the axes of a receiver operating characteristic curve?

A

y = sensitivity

x = 1 - specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the main purpose of a meta-analysis?

What are the other 3 purposes?

A

To increase power
• Resolve uncertainty
• Improve estimates of effect size (precision)
• Answer other questions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What should you consider when wondering if a study is relevant to your patient?

A

PICOT

Population

Intervention

Comparator

Outcome

Time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the 4 elements of autonomy in medical ethics?

A

Freedom to make your own decisions. No coercion No manipulation No deceit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What percentage of travellers visiting a developing country will develop a health problem?

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the most common cuase of death in travellers?

A

Cardiovascular disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Define beneficence in a medical ethics context

A

Promote health and well-being

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the 5 ethical principles?

A

Non-maleficence Beneficence Autonomy Justice Dignity (never be a jerk doctor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the most common serious medical condition in travellers?

A

Malaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Define non-maleficence is a medical ethics contect

A

Do no harm, or minimise harm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Which ethical principle is informed consent most important for?

A

Autonomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Define respect for dignity in a medical ethics context

A

All people are of equal moral worth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the most effective public health measure to decrease tobacco usage?

A

Increasing taxation

45
Q

How is population atributable risk percentage calculated?

What does it tell you?

A

100 x (Rt-Ru)/Rt

Proportion of incident disease among whole population that is due to exposure.

46
Q

Define incidence

A

Number of new cases of a disease within a specified time period

47
Q

Define prevalence

A

Number of exisitng cases of disease at a particular point in time.

It depends on both incidence and duration of disease

48
Q

Chronic diseases have greater ______ than ______, but diseases with poor survival would have higher_______ than ______.

A

Chronic diseases have greater prevalence than incidence, but diseases with poor survival would have higher incidence than prevalence.

49
Q

What is a systematic review?

A

Lit review paper which analyses multiple papers surrounding single research question.

These studies include RCTs, as well as cohort and observational studies. RCTs are the highest level of evidence.

Inclusion criteria (sub-population, sample size, methodology)- uses consort checklist

“A literature review focused on a single question which identifies, appraises, selects and synthesises high-quality evidence relevant to that question. It is considered the highest level of evidence.”

50
Q

What is a meta-analysis?

A

The statistical component of a systematic review (of the many research papers) which includes weighted averages of the papers’ findings. Increases power and confidence of findings (more samples), and decreases uncertainty

May be able to find secondary outcomes.

51
Q

What does the solid, vertical line represent?

A

Line of no effect; placebo=txt therefore no difference between the interventions on outcome.

52
Q

What do the squares-and-lines and diamonds represent?

A

squares= weighting of the study

lines= confidence interval

diamonds= pool of effect; combined result of the studies

last diamond= overall pooled effect

53
Q

What is the difference between a type 1 and type 2 error?

A

T1= false positive

T2= false negative

54
Q

What is Public Health?

A

Science and art of preventing disease and improving health through the organised efforts of society

55
Q

What is Population Health

A

The health outcomes of a group of individuals, including the distributions of outcomes within the group

56
Q

What are the three types of prevention?

A

Primary Prevention- Reduce likelihood of developing diseaseSecondary Prevention- Prevents or minimises progress of diseaseTertiary Prevention- Reduces Progression of damage already done

57
Q

What is Epidemiology?

A

Study of Distribution and Determinants of Disease

58
Q

What is Incidence?

A

Number of new cases of a disease within a specified time period. Expressed as a rateLongitudinal studies neededPoor Survival will have a higher incidence than prevalence

59
Q

What is Prevalence?

A

Number of existent cases of disease at a particular point of time. Expressed as a proportion

60
Q

What is the prevalence if Incidence and Duration are constant over time?

A

P=ID

61
Q

What is Risk?

A

Probability of disease occurring in a disease free population during a specified time periodRisk= Number new cases/ Population at risk

62
Q

What is Rate?

A

Probability of disease occurring in a disease free population during the sum of individual follow up periodsRate = New cases in a defined period total person time / Total person-time of follow up

63
Q

What is absolute risk/rate

A

isolated measure of risk/rate (specific)Eg. 5 strokes/10,000 men per year

64
Q

Formula for Relative Risk?

A

RR= Re/Ru (exposed/unexposed)Indicates relative magnitude of exposure

65
Q

Formula for Attributable Risk?

A

AR= Re-RuIndicates the absolute of change in risk/rate of outcome

66
Q

What are the features of a cross sectional study?

A

Sample of population selected at one point in timeEach subject only contributes data once (no follow up)Mostly descriptive outputs

67
Q

What are the advantages and disadvantages of cross sectional studies?

A

Relatively cheap and easyneed for representative sampleexplore associations among variables, but no explicit data on temporal relationshipweak evidence of causality

68
Q

What does the attributable risk percentage represent?

A

percentage of incident disease among exposed people that was due to the exposureAR/Re x100

69
Q

How is data collected in cross sectional studies?

A

Questionnaires, examinations, investigations. Prevalence mainly looked at

70
Q

What is a case control study?

A

Comparison of previous exposure status between cases and controls. Looks at the effect of an exposure on an outcome of interst.

71
Q

What is the purpose of matching during a case control study?

A

Reduce confound variables having a bias.

72
Q

What are the advantages and disadvantages of case control studies?

A

gives explicit knowledge about temporal relationship between exposure and outcome (exposure came before outcome)Useful for studying rare outcomes.

73
Q

What are cohort studies? Does it use OR or RR?

A

Longitudinal studies done with follow up of subjects to collect incidence data. Compares outcomes between those exposed and not exposed to a risk factor and relative risks are derived

74
Q

What are the advantages and disadvantages of cohort studies?

A

Advantages: explicit and detailed knowledge about temporal relationship b/w exposure and outcome.-Can include multiple exposures and outcomes-cohorts can be established as part of routine clinical careDisadvantages-Difficult for rare outcomes-More difficult and expensive

75
Q

Why is retrospective cohort study still considered a longitudinal study?

A

Study is begun at a time where a cohort has already been established and data is available about an exposure in the past

76
Q

What is Bias?

A

An Unintentional error due to a systematic difference between or among groups which leads to under or over-estimaion of true results.

77
Q

What are the two main types of bias?

A

Selection and Information (measurement)

78
Q

What is selection bias?

A

systematic difference in characteristics of people selected for study and those not selected. eg. selecting only people that can speak english. Systematic diff. within groups also lead to selection bias-eg. recruiting cases within hospital but controls outside.

79
Q

How is selection bias minimised?

A

careful recruitment (rep. sample of population, and cases and controls from same source)Maximise responseMinimise subjects lost to follow-up

80
Q

What is information bias?

A

Systematic difference in how information is collected. Arises when variability in methods of collecting data.

81
Q

What is recall bias?

A

Type of information bias where cases are more likely to recall presence of exposure due to already established prejudice about association b/w the risk factor and the outcome.

82
Q

How is information bias minimised?

A

Uniform collection methods of information between or among groups being compared.

83
Q

What is confounding variables? What are two examples?

A

Influences relationship between exporsure and outcome. A third variable that indepenently affects the outcome, and is related to the exposure. Age and sex are examples.

84
Q

How is confounding minmised?

A

Design and execution stages: match by confounder or restriction (eg only select males)Analysis: Stratification and multivariate analyses

85
Q

How does randomisation help to deal with confounding?

A

Makes treatment groups identical in all aspects other than the intervention in order to reduce the effect of confounders.

86
Q

What is intention to treat analysis and what is it used for?

A

Helps deal with selection bias. People lost to follow up (eg cross over: people started on place start taking drug, or people assigned to drug stop taking it) is a source of selection bias if it is significant. Intention to treat assumes subjects remained in their randomised group, regardless of what the did in real life. Intetnion to treat always under estimates any treatment effect (ie conservative). Cross over introduces overlap in treatment between groups, but ITT ignores this effect, a positive ITT therefore give more confidence.

87
Q

What is Hazard?

A

Continuously updated, instantaneous rate which is measured in longitudinal studies with close follow up.HR is Similar to OR and RR, except it does not reflect a time unit of the study.

88
Q

What is the survival analysis?

A

During follow, explicitly captures of outcome and their time of occurrence. Survival analysis measure ‘time to event’

89
Q

What is a Hazard ratio of 0.5?

A

at any given point in time within the period of followup, the probability of outcome in the intervention group is half of that of the control group.

90
Q

What is the number needed to treat and how is it calculated?

A

NNT= number of people needed to undergo the intervention in order to prevent outcome in one. It is a marker of efficiency of the intervention. NNT= 1/(absolute risk or rate reduction)

91
Q

How do internal and external validity differ?

A

Internal refers to how well a trial deals with limitations such as bias confounding. External validity refers to the applicatbility of the trial results.

92
Q

What does PICOT stand for?

A

P= populationI= InterventionC= Comparator/controlO= OutcomeT= Timing

93
Q

What is internal validity?

A

Extent to which the results are valid (accurate, robust etc.) Dependant on study design, data collection and analyses.

94
Q

What is Stratified Randomisation?

A

Randomisation by levels of key confounders= eg dividing groups into male and female then randomising from there.

95
Q

What is the p-value?

A

Probability that the observed result arose from chance.

96
Q

What does the width of the 95% confidence interval measure?

A

Precision of result.

97
Q

How is external validity assessed?

A

Determining the degree of concordance between RCT and the clinical setting in terms of PICOT

98
Q

How do you calculate Odds Ratio

A

(odds of outcome among exposed)/(Odds of outcome among unexposed)OR= AD/BC

99
Q

What is the difference between phase 1 and 2 in clinical trials?

A

Phase 2 targets a larger, unhealthy population with placebo (safety and efficacy) whereas phase 1 is just to a small healthy group (safety and side effects).Test whether it works in phase 2.

100
Q

What is clinical trial phase three?

A

Drug given to large group of people, measure effectiveness, monitor side effectsCompare to commonly used treatmentsCollect information that allows the drug to be used safely (Can sometimes be released at 3)

101
Q

What is Phase IV for clinical trials?

A

After drug has been marketed. Long term effectiveness and any side effects with long term use. Can be an observation study (ie. seeing performance in other countries before trialling in own)

102
Q

Which studies contribute the most weight in a meta-analysis?

A

Larger studies, studies with low CI

103
Q

What are likelihood ratios?

A

likehood that a given test result would be expected in a pt with the disease compared to pt w/o the disease

LR of positive test= sensitivity/ (1-specificity)

LR of negative test= (1-senstivity)/specificity

104
Q

What are the biases involved in screening programs? Explain them.

A
  • Selection bias: the healthy are more likely to be screened
  • Lead-time bias: seems to be more effective due to earlier detection, not actual prolonged survival
  • Length-time bias: diseases which have a slower progression will be selected for as there is more time to detect the disease (aggressive diseases would cause death a lot earlier)
105
Q

Odds ratio is most often used in ________ studies

A

case-control

106
Q

Relative risk is often used in ______ and ______ studies

A

Clinical trials and cohort

107
Q

_______ study - suited to studying causes of rare disease.

A

Case-control

108
Q

Sensitivity vs specificity?

A

Test sensitivity is the ability of a test to correctly identify those with the disease (true positive rate), whereas test specificity is the ability of the test to correctly identify those without the disease (true negative rate).