Epidemiology Flashcards

Question

incidence rates obtained from

Answer 1

longitudinal studies or derived from registers

Answer 2

chronic incurable disease like diabetes can have a low incidence but high prevalence, because the prevalence is the cumulative sum of past year incidence rates - Prevalence is cumulative sum of last year incidence rates How many patients need diabetic drugs/care

Answer 3

short-duration curable condition such as the common cold can have a high incidence but low prevalence, because many people get a cold each year, but few people actually have the cold at any given time (so prevalence low)

Answer 4

prevalence

Answer 5

Can be chronic but want to know incidence as people die quite rapidly - Trend over time But depends on nature of chronic disease

Answer 6

time (when) place (where) person (who)

Answer 7

``` dat circadian weeks months yearly ```

Answer 8

Globally (burden of disease – oral disease, caries), countries, MEDCs or LEDCs - Scottish Index of Multiple deprivation towns, communities/regions,

Answer 9

age gender ethnicity

Answer 10

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 groups of individuals with different characteristics Correlations may then be sought with other variables resulting in hypothesis of cause

Answer 11

the burden of disease

Answer 12

reduces no. of individuals to be sampled reduces cost higher response rate higher quality of information collected

Answer 13

Sample must be representative of population being investigated. - Aim is to avoid bias or being skewed

Answer 14

don't need to ask everyone in population but must be representative so margins of error lie likely where true value is

Answer 15

simple random sample systematic sample stratified sample cluster sample multi-staging sample

Answer 16

uses random number tables/generators

Answer 17

individuals selected at regular intervals from population list (every 2nd, 3rd) - logical open to bias (how they are ranked)

Answer 18

ensures small sub-groups adequately represented | e.g. Scottish index of multiple deprivation (into fifths)

Answer 19

use of groups as sampling units, e.g. school classes | - more practicable

Answer 20

combines above techniques | - 20% of schools from each level of deprivation

Answer 21

error and bias in survey methodology

Answer 22

Sampling bias / selection bias - Skew data Response bias / information bias - Need to monitor who responds - could only be affluent educated (then miss a proportion) Measurement error ``` Observer variation (intra- or inter-) - needs to be Standardised ``` Loss to follow-up

Answer 23

- Inta – minimal, sampler is consistent, repeatability | - Inter – between samplers

Answer 24

to measure disease need an appropriate index Measuring for the purposes of epidemiological studies different from recording disease for patient treatment purposes - More objective - Not subjective description of decay Standardised measurement

Answer 25

clear, unambiguous, not subjective ideally correspond with clinically important stages of the disease indicate treatment need within the ability of examiners reproducible not time-consuming acceptable to patient (no harm) amenable to statistical analysis allow comparison with other studies

Answer 26

DMF index - first described in 1937 DMFT: decayed, missing & filled teeth (0-32) DMFS: decayed, missing & filled surfaces (0-148) - Distal, mesial, occlusal, buccal and lingual (incisors don’t have occlusal) Deciduous teeth: dmf/def index - dmf: deciduous decayed, missing and filled teeth (0-20) - e = indicated for extraction / exfoliated at age 6 (& over) only score “c, d, e”

Answer 27

Teeth extracted for reasons other than caries - Perio, trauma, missing naturally (M wrong), overestimation Influenced by access, e.g. interproximal surface Difficulty in differentiating fissure-sealant from restorations – underestimate caries Influenced by past disease activity - Historical caries experience - Not necessarily at the time you examine Threshold criteria of disease can vary (must specify) Cannot be used for root caries

Answer 28

pulpal and decay in dentine - both visible obvious decay not enamel or sub-clincal decay

Answer 29

Scottish dental epidemiological programme of children - Renamed from SHBDEP (Scottish Health Boards’ Dental Epidemiological Programme) (1987 – 2000) in 2002 Cross-sectional, descriptive dental surveys of school children Larger samples than UK decennial surveys Involve standard examination criteria and trained and calibrated examiners Target groups: children in P1 and P7 - Basic inspection for all children in P1 &P7 every year Detailed inspection (epidemiology) for a sample of children every year - Alternates each year between P1 and P7 - NHS Board can add additional year groups - Sample more detailed DMFT sub-sample

Answer 30

Aims to inform: - parents of their child’s dental health status (Basic NDIP) - advise Scottish Government, NHS Boards, and other organisations of the oral disease prevalence in children in their area (Detailed NDIP – Epidemiology survey) like a census goals - to inspect a representative sample of the P1 or P7 LA school population in any year - to determine current levels of established tooth decay - to illustrate the impact of deprivation on the dental health of 5 & 11 year old children in Scotland

Answer 31

Offered to every child in P1 and P7 classes of local authority schools every year Proportion of school rolls inspected 85-90% Generates letter to parent - Overall state of dental health of child - Conveys degree of urgency with which appointment for attendance at dentist suggested for child Not a detailed examination of each surface of each tooth

Answer 32

Detailed Inspection - more rigorous and comprehensive assessment - Calibration of examiners - records status of each tooth surface in accordance with international epidemiological conventions (i.e. d3mft: caries into dentine)- can be underestimate - Uses same clinical inspection criteria as SHBDEP - can therefore look at trends from 1987 re P1 children

Answer 33

- to inspect a representative sample of the P1 or P7 LA school population in any year - to determine current levels of established tooth decay - to illustrate the impact of deprivation on the dental health of 5 & 11 year old children in Scotland

Answer 34

Number of children e.g. 10 selected for calibration exercise - High proportion should have caries Potential dental epidemiology examiners then all examine and chart each child Compare results - Assess inter-observer variation - Each child should have same level of decay from every examiner Outlier dental examiners not able to participate in epidemiological programme

Answer 35

Assesses need and eligibility of children for NHS orthodontic treatment on dental health grounds (treatment need scale used on clinic for treatment planning) Selects those children who will benefit most from treatment; fair way to prioritise limited NHS resources Dental Health Component (DHC) has 5 Grades and Aesthetic Component (AC) has 1-10 scale

Answer 36

- scale of 10 colour photographs showing different levels of dental attractiveness - AC used for border-line cases with Grade 3 DHC. If high AC score, NHS treatment is permissible

Answer 37

5 grades - Grade 1: almost perfection, to - Grade 5: for severe dental health problems E.g. upper front teeth that protrude more than 9 mm

Answer 38

- Debris Index (Green & Vermillion, 1960) | - Plaque Index (Silness & Loe, 1964)

Answer 39

- Modified Gingival Index (Loe, 1967) | - Lobene Index (Lobene, 1986)

Answer 40

basic periodontal exam (BPE, CIPTN)

Answer 41

- plaque indices - gingivitis indices - periodontitis indices

Answer 42

- Fluorosis Index (Dean, 1934) - TF Index (TFI) (Thylstrup & Fejerskov, 1978) - Tooth Surface Index of Fluorosis (TSIF) (Horowitz et al, 1984) - SCOTS Index (Scots HBs Child assessments of Opacities by tooth-Thirds & Symmetry) (Pitts & Stephen, 1991

Answer 43

when upper anterior teeth erupt | - blotchy - issue aesthetically

Answer 44

Not considered a public health problem in Scotland Low impact to patient and profession Will be monitored through NDIP programme - Potential impact of childsmile programme - Due to increase in F in childsmile toothpaste (1450 ppm)