epidemiology Flashcards
1
Q
what is the definition of epidemiology
A
is the study of a population in order to determine the frequency and distribution of disease
- it helps in identifying risk factors for disease and determinant optimal treatment approached to clinical practice and preventive medicine
2
Q
what was the starting point of epidemiology
A
- John Snow broad street pump cholera epidemic, London, 1854
- one of the 1st recorded examples of epidemiology to investigate and manage of infectious disease
3
Q
what is cholera
A
- an infection in the small intestine caused by the bacterium vibe cholera
- main symptoms are profuse, watery diarrhoea and vomitting
- transmission occurs through drinking water or eating food contaminated
- the severity of diarrhoea can lead to dehydration and even death
4
Q
what happened in the investigation of the broad street pump
A
- John snow was recording it and finding links between areas of infection
- mapping the areas found that they were all near the pump
5
Q
what was the intervention to the broad street pump epidemic
A
- the pump handle was removed as intervention so people couldn’t use it anymore - a dramatic reduction in cases was seen
6
Q
what are the major roles of epidemiology
A
- monitor infectious disease and non infectious diseases
- study natural history of disease
- investigation of disease risk factors
- health care needs assessment
- development of preventive programmes
- evaluation of interventions
- health service planning
7
Q
how is the flu monitored
A
- stats are monitored weekly for the flu
- it is an infectious disease
- it is monitored to see if it is a pandemic or not
8
Q
what is an example of a pandemic flu
A
- swine flu
- affected young people as well as elderly people
9
Q
how are non-infectious diseases monitored
A
yearly
- such as lung cancer
10
Q
why are diseases studied
A
- to determine if they are self limiting, chronic or fatal or unknown
- oral cancer is an example of a fatal disease
11
Q
what is an example of an unknown disease history
A
- HPV
- it is known there is a link between it and oropharyngeal cancer but unsure of the link
12
Q
what is considered in health care assessment for epidemiology
A
- what care services are required by particular population groups
- dependant on health status and demographics of population
13
Q
what are development of preventive programmes based on
A
- knowing risk factors of diseases and attempting to prevent exposure to these factors
14
Q
what is an example of proportional prevention
A
- childsmile
- meets needs of certain part of the population
15
Q
what are the 3 types of epidemiological study
A
- descriptive (observational)
- analytic (observational)
- intervention/experimental
16
Q
what is descriptive epidemiology
A
- measure of disease frequency
17
Q
what is prevalence
A
- a measurement of all individuals affected by the disease at a certain point in time
- number of existing cases
- number of affected individuals divided by total number of persons in population
- estimates are obtained from cross-sectional studies of derived from registeries
18
Q
what is prevalence used for
A
- as an estimate of how common a condition is within a population is at a certain point of time
19
Q
what does d3mft mean
A
- decayed missing or filled teeth
- 3 means that it is decay into dentine so is substantial
20
Q
what is incidence
A
- a measurement of the number of new individuals who contracted a disease during a period of time
- number of new cases or events during a specific period of time in a defined population
- incidence estimates are obtained from longitudinal studies or derived from registries
- always expressed as a fraction
21
Q
what is the difference between oral cancer and oropharyngeal cancer
A
- HPV is only present in oropharyngeal cancer
22
Q
what is the difference between prevalence and incidence
A
- prevalence is at one point in time incidence is over a period of time
- a chronic incurable condition like diabetes can have a low incidence but high prevalence because prevalence is the cumulative sum of the past year incidence rates
- a short duration disease such as the common cold can have high incidence but low prevalence as many people get a cold a year but not many people may have it at one point in time
23
Q
what are the main variables of descriptive epidemiology
A
- time
- place
- person
24
Q
what are the aims of descriptive epidemiology
A
- identify changes in incidence or prevalence over time
OR - determine incidence or prevalence of disease in different geographical areas
OR - determine incidence/prevalence of disease in a group of individuals with different characteristics
25
what is an example of a time and place study
"obesity trends in US adult population by US state, 1985-2003"
26
what is the SIMD
- Scottish index of multiple deprivation
- 1-5
5 is most deprived
27
what are the advantages of a sample
- reduces number of individuals to be sampled
- reduces cost
- higher response rate
- higher quality of information collected
- sample must e representative if population being investigated = aim is to avoid bias
28
what are some sampling techniques
- simple random sample = use of table of random numbers
- systematic sample = individuals selected at regular intervals from list
- stratified sample = ensures small sub-groups adequately represented
- cluster sample = use of groups as sampling units
- multi-stage sample = combines above techniques
29
what are some errors and bias in survey methodology
- sampling/selection bias
- response bias/information bias
- measurement error
- observer variation
- loss to follow up
30
why is an index need
- in order to measure disease you need an appropriate index
| - measuring for the purposes of epidemiological studies different from recording disease for patient treatment purposes
31
what are the properties of an ideal index
- clear, unambiguous, not subjective
- ideally correspond with clinically important stages of the disease
- indicate treatment needed
- within ability of examiners
- reproducible
- not time consuming
- acceptable to patient
- amendable to statistical analysis
- allow comparison wit other studies
32
what is the DMF index
- 1st used in 1937
- for adult teeth = 0-32 DMFT, 0-148 DMFTS (surfaces)
- for children = e = extraction, at age 6 or over only score c,d or e
33
what are the limitations of the dmf index
- teeth extracted for reasons other than caries
- influenced by access - inter proximal surfaces harder
- difficulty in differentiating between fissure-sealants from restorations
- influenced by past disease activity
- threshold criteria for disease can vary
- cannot be used for root caries
34
how often are surveys done in the UK for children caries
- every 10 years
- small number of children
- BASCD annual surveys organised locally around the UK
35
what is the NDIP
- national Dental inspection programme
- Scottish epidemiological programme of children
- renamed in 2002
- cross-sectional descriptive dental surgery of school children
- involve standard examination criteria and trained calibrated examiners
36
what are the aims of NDIP
- inform parents of their Childs dental health status (Basic NDIP)
- advise Scottish government, NHS boards and other organisation of the oral diseases prevalence in children in their area (detailed NDIP)
37
what are the target groups for NDIP
- children in P1 and P7
- basic inspection for all P1 and P& children every year
- detailed inspection alternates each year between P1 and P7
- NHS board can add additional year groups
38
what is a basic NDIP
- offered every child in P1 and P7 classes of local authority schools every year
- proportion of school rolls inspected 85-90%
- generates a letter to parent = overall state of dental heath of child, conveys degree of urgency with which appointment for attendance at dentist suggested for child
- not a detailed inspection of each surface of each tooth
39
what is a detailed NDIP
- detailed inspection = more rigorous, calibration of examiners
- records status of each tooth surface in accordance wit international epidemiological conventions
- uses same clinical inspection criteria as SHBDEP
40
what are the specific goals of detailed NDIP
- to inspect a representative sample of the P1 or P7 LA school population in a year
- to determine current levels of established tooth decay
- to illustrate the impact of deprivation on the dental halt of 5 and 11 year olds children in Scotland
41
what is calibration of epidemiology studies
- number of children e.g. 10 are selected for calibration exercise
- potential dental epidemiology examiners then all examine and chart each child
- compare results = asses inter-observer variation
- outlier dental examiners not able to participate in epidemiological programme
42
what is the TF index
- for fluorosis
- TF 0 - TF 4
- 0= good, 4= bad fluorosis
43
what is dental fluorosis Scotland
- not considered a public health problem
- low impact to patient and profession
- will be monitored through NDIP programme
44
what is the IOTN
- index of ortho treatment need
- assess the needs and eligibility of children for NHS orthodontic treatment on dental health grounds
- selects those children who will benefit most from treatment
45
what is the DHC component to index of ortho treatment need
- dental health component
- has 5 grades
- grade 1 = almost perfection
- grade 5 = for severe dental problems
= upper front teeth that protrude more than 9mm
46
what is the aesthetic component of the index of ortho treatment need
- scale of 10 colour photographs showing different levels of dental attractiveness
- AC is used for border-line cases with Grade 3 DHC = if high AC score, then NHS treatment is permissible
- 1 = perfect, 10= needs ortho
47
what is the trend in adult dental health survey tooth loss
- improvement in percentage of adults retaining natural teeth
- in those ages under 45 years, total tooth loss is virtually a thing of the past
- prediction for the future = % adults with no natural teeth expected to be in single figure in all groups up to 74 years old by 2028
48
what are the plaque indices of periodontal disease
- debris index = Green and Vermillion 1960
| - plaque index = Silness and Loe 1964
49
what are the gingivitis indices for periodontal disease
- modified gingival index = Loe 1967
| - loben index = loben 1986
50
what are the periodontal indices for periodontal disease
- basci periodontal examination (BPE)
