Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medical Finals > Epidemiology > Flashcards

Epidemiology Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

Define ‘routine data’

A

Data that are routinely collected and recorded in an ongoing systematic way, often for administrative purposes

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

What are the advantages & disadvantages of using routine data?

A
  • Advantages
    • Relatively cheap
    • Already collected/available
    • Standardised collection procedures
  • Disadvantages
    • May not answer the question
    • Variable quality
    • Not every case captured
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the coding systems for diagnoses and procedures in hospital?

A
  • Diagnoses- ICD10
  • Procedures - OPCS4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the advantages to using hospital episode statistics for study?

A
  • Advantages
    • Comprehensive
    • Unbiased
    • Based on case notes
  • Disadvantages
    • Data may not be complete
    • In hospital death only
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the top 3 causes of UK mortality?

A
  1. Heart and circulatory disorders 33%
    • IHD 23%
    • Stroke 10%
  2. Cancer 30%
    • Trachea, bronchus, lung
    • Breast, prostate
    • Colorectum
  3. Respiratory disorders 13%
    • Pneumonia
    • COPD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the top 5 causes of mortality worldwide?

A
  1. IHD
  2. Stroke and other cerebrovascular disease
  3. LRTI
  4. COPD
  5. Diarrhoeal diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define ‘clinical governance’

A

A transparent system for the continual maintenance and improvement of healthcare standards both on an individual and organisational level within the NHS

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

What are the elements of clinical governance?

A
  • Education and training
  • Clinical audit
  • Clinical effectiveness
  • Research and development
  • Openness
  • Risk management
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the Care Quality Commission do?

A
  • Independently inspect healthcare services against standards set by the DoH
  • Investigate serious failures in healthcare services
  • Publish regular ratings of NHS trusts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define ‘clinical audit’

A

A quality improvement process that seeks to improve patient care and outcomes through the systematic review of care against explicit criteria and the implementation of change

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

How common is overweight/obesity in the UK and what risks does this confer?

A
  • 20% obese, 50% females overweight
  • Nurses’ health study
    • overweight -> 3 years less life
    • Obese -> 7 years less
    • Active lifestlye (30 min walk per day) prevents 30% obesity and 45% new DM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How common are sexual health issues in the UK?

A
  • 10% 16-24 year olds have ≥1 STI
  • Increased in urban areas and amongst blacks and minorities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the recommended alcohol limit and how many people have alcohol issues in the UK?

A

14 units/week (1 unit = 10ml EtOH)

5% men and 2% women report problems

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

How common are mental health problems in the UK?

A

15% lifetime risk (most commonly depression and anxiety disorders)

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

What is the hierarchy of evidence?

A
  1. Systematic review and meta analysis
  2. RCTs
  3. Cohort or case control studies
  4. Descriptive studies
  5. Case reports
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the point of descriptive studies?

A

Can generate hypotheses and provide frequency data (incidence/point prevalence); can’t determine causation

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

What are some examples of descriptive studies?

A
  • Cross sectional surveys/census
  • Ecological studies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are case control studies?

A

Retrospective study of exposure in a case group (with the disease) and a control group (without). The proportion of exposed in each group generates an odds ratio

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

What are the pros and cons of case control studies?

A
  • Pros:
    • Quick and cheap
    • Well suited for diseases with long latent periods
    • Good to evaluate rare diseases
    • Can examine multiple aetiological factors for a single disease
  • Disadvantages
    • Inefficient for evaluating rare exposures
    • Cannot calculate incidence rates
    • Temporal relationship between exposrue and disease can be difficult to establish
    • Recall bias
    • Selection bias
20
Q

What is a cohort study?

A

Prospective study comparing development of disease in exposed and non exposed groups. Incidence of disease in each group -> relative risk

21
Q

What are the pros and cons of cohort studies?

A
  • Pros
    • Good for evaluating rare exposures
    • Can examine multiple effects of a single exposure
    • Can elucidate temporal relationship
    • Direct incidence calculation
  • Cons
    • Inefficient for evaluation of rare diseases
    • Expensive and time consuming
    • Loss to follow up affects results
22
Q

What is an RCT?

A

A planned experiment designed to assess the efficacy of an intervention. Randomisation decreases selection bias and blinding decreases measurement bias

23
Q

What are the pros and cons of RCTs?

A
  • Pros
    • Most reliable demonstration of causality
  • Cons
    • Non compliance
    • Loss to follow up
    • Validity depends on quality of study
    • Ethical issues
    • Selection criteria may limit generalisability
24
Q

How do you interpret a forest plot?

A
  • Square = OR
    • size = size of study
  • Line = 95% CI of OR
  • Diamond = combined odds ratio
    • Width = 95% CI
25
Q

What are the 5 steps of EBM?

A
  1. Question
  2. Search
  3. Appraise
  4. Apply
  5. Evaluate
26
Q

What are the Bradford Hill causation criteria?

A
  • Strength of association
  • Consistency
  • Specificity
  • Temporal relationship
  • Dose response/biological gradient
  • Plausibility
  • Coherence
  • Experiemntal evidence
  • Analogy: if a similar association can be demonstrated in another setting
27
Q

Define ‘bias’

A

Inaccurate data due to systematic error in selection, measurement or analysis

28
Q

What is selection bias?

A

Systematic difference between the characteristics of those selected for a study and those who were not or differences between study groups

29
Q

What is measurement bias?

A

When measurements or classifications of disease or exposure are inaccurate e.g. inaccuracies of instruments, expectations of observers or participants

30
Q

What is analysis bias?

A

Error caused by participants being lost to followup or switching treatment groups.

31
Q

What is confounding and what are some common confounders?

A

Error in the interpretation of an accurate measurement - a confounder is any factor which is prognostically linked to the outcome and is unevenly distributed between study groups. Not a confounder if it lies on the causal pathway between the variables of interest.

Commonly: age, sex, SES

32
Q

How can you reduce confounding?

A
  • Randomisation
  • Stratification
  • Standardisation e.g. SMR
    • Ratio of observed:expected deaths
    • Expected deaths derived from larger population
  • Regression
33
Q

What is the odds ratio?

A

=odds of exposure in cases/odds of exposure in controls

OR = ~RR if disease is rare (<10%)

34
Q

What is the relative risk?

A

Increase/decrease in probability of a disease given a particular risk factor

=incidence in exposed/incidence in unexposed

35
Q

What is the attributable risk?

A

The measure of excess risk due to a factor

36
Q

What are the modified Wilson criteria?

A

For determining whether a screening programme is worthwhile:

  • Disease
    • Important health problem
    • Well recognised pre clinical stage
    • Natural history well understood
  • Test
    • Valid and reliable
    • Simple and cheap
    • Safe and acceptable
  • Diagnosis and treatment
    • Adequate facilities
    • Acceptable treatment
    • Early intervention is of more benefit than later treatment
  • Cost effective
37
Q

What is the difference between sensitivity, specificity, PPV and NPV?

A
  • Sensitivity: detect true positives
  • Specificity: exclude true negatives
  • PPV: how likely to have disease if positive
  • NPV: how likely to not have disease if negative
  • PPV and NPV depend on disease frequency
38
Q

What are some biases affecting the effectiveness of a screening programme?

A
  • Selection bias: healthiest come for screening
  • Lead time bias: disease diagnosed earlier -> increased survival time
  • Length time bias: outcome appears better because more disease with good outcome detected
39
Q

What is primordial prevention?

A

Prevention of factors promoting the emergence of risk factors: lifestyle, behaviours, exposure patterns

40
Q

What is primary prevention?

A

Prevention of disease onset e.g. vaccination

41
Q

What is secondary prevention?

A

Halting progression of established disease by early detection followed by prompt, effective treatment

42
Q

What is tertiary prevention?

A

Rehabilitation of people with established disease to minimise residual disability and complications

43
Q

What is the prevention paradox?

A

Many people exposed to a small risk may generate more disease than a few exposed to a large risk. So when many people receive a small benefit the total benefit may be large. However, individual inconvenience may be high to the many while benefit is only to a few.

44
Q

What is likelihood ratio?

A

Measure of how much a test alters your probability of the disease.

LR = p [test result if disease present]/ p [test result if disease absent]

LR for positive result = sensitivity/(1-specificity)

LR for negative test result = (1-sensitivity)/specificity

Post test odds = pre test odds x likelihood ratio

45
Q

What are the reasons to terminate a study early?

A

Safety concerns, overwhelming benefit, futility

Medical Finals (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions