30. Epidemiology Flashcards
(30 cards)
1
Q
Define ‘epidemiology’
A
- scientific method of studying disease in populations
- study of distribution and determinants of disease frequency in human populations
- in dentistry, includes measurement of dental disease in populations, evaluates effectiveness of treatment and assess needs/demands
2
Q
3 components of epidemiology
A
- distribution
- frequency
- determinants
3
Q
What is distribution in epidemiology?
A
- who is getting a disease?
- where/when is it occurring?
- are there patterns of disease?
4
Q
What is frequency in epidemiology?
A
- quantification of existence and occurance of disease
5
Q
What is determinants in in epidemiology?
A
- derived from data obtained from distribution and frequency
- necessary to test an epidemiologic hypothesis
6
Q
Process of epidemiology
A
- a suspicion exists that a particular factor may be influencing occurrence of a disease (your suspicion may arise from clinical practice, observation, research)
- formulation of a specific hypothesis
- hypothesis is tested in epidemiological studies with comparison group
- collect and analyse data to determine whether a statistical association exists
- assess validity of any observed association by excluding alternative explanations like chance, bias, confounding etc
- does statistical association suggest a causal relationship?
7
Q
What is looked at to see if statistical association suggests a causal relationship?
A
- magnitude of association
- other studies
- consistency of findings against other studies
- biological credibility
8
Q
Ways to measure disease
A
- indices
- standardisation
- quantify it
- indirectly - evaluation of effectiveness
9
Q
A ‘gold standard’ measure of dental disease would be …
A
- valid
- reliable
- objective
- simple
- reproducible
- quantifiable
- sensitive
- accceptable
10
Q
List descriptive study designs
A
- observational
- case-reports
- case-series
- cross-sectional
11
Q
Give analytic study design
A
- observational - case-control, cross-sectional
- experimental - clinical trials
12
Q
Give study designs from bottom to strongest methodology
A
- animal and lab research
- case reports/case series
- case control studies
- cohort studies
- randomized controlled trials
- systematic reviews
- meta-analysis
13
Q
Case-studies/case-series are used for …
A
- highlighting interesting or novel cases/treatment
- recognition of new disease/outcome
- formulation of new hypotheses
14
Q
Disadvantages of case studies/case series
A
- cannot demonstrate valid statistical association
- lack of appropriate comparison group can obscure a relationship or suggest an association where none exists
15
Q
Define ‘case-report/case-series’
A
a report on a single patient or series of patients with an outcome of interest
- no control group required
16
Q
What is a cross sectional study?
A
- observation of a defined population at a single point in time (or time-interval)
- exposure and outcome are determined simultaneously
17
Q
Cross sectional surveys are used for …
A
- measuring prevalence of disease
- look at potential risk factors or cause
18
Q
Disadvantages of cross sectional surveys
A
- may establish association, NOT causality
- confounders may be unequally distributed
- group sizes may be unequal
- recall bias
19
Q
What’s a cohort studies?
A
- involves identification of two groups (cohorts) of patients
- one which received the exposure of interest
- one which did not
- and following these cohorts forward to assess the outcome of interest
20
Q
Cohort studies are used for …
A
- measures the incidence of disease
- looking at causes of disease
- determining prognosis
- establishing timing and directionality of events
21
Q
Disadvantages of cohort studies
A
- controls may be difficult to identify
- exposure may be linked to hidden confounder
- blinding is difficult
- for rare diseases, large sample size is often necessary or a long follow up
22
Q
What is a case-control study?
A
- a study which involves identifying patients who have the outcome of interest (case)
- and patients without same outcome (controls)
- looking back in time to see if they had the exposure of interest
23
Q
Case-control studies are used for …
A
- looking at potential causes of disease
- suitable for rare diseases
24
Q
Disadvantages of case-control studies
A
- confounders
- selection of controls may be difficult
- recall and selection bias
- difficult to establish time relationships between exposure to risk factor and development of disease
25
Randomised Controlled Trials are used for ...
evaluating the effectiveness of an intervention
26
Disadvantages of randomised controlled trials
- high costs
- ethical issues
- participant compliance
27
How are randomised controlled trials random?
- exposure status assigned by researcher preferably by random allocation
- best way to reduce selection bias between 2 groups of participants
28
Define 'systematic reviews'
- the evidence from a number of studies can be gathered together in one report
- which pools and analyses all available data to assess the strength of evidence
29
Why do a systematic review?
- can end confusion
- highlight where there isn't enough evidence
- yield new insights by combining findings from different studies
30
Key features of a systematic review
- needs to be an analysis of evidence not just a review
- question needs to be defined precisely defining population and outcomes so studies included are appropriate and comparable
- complete methods available detailing comprehensive searching for all evidence and author quality guidelines
