epidemiology 3 Flashcards
what is the role of epidemiology
- measurement of amount and distribution of disease, and natural history of disease
- study of causes/determinants of diseases
- asses people’s risk of disease
- development of preventive programmes
what is epidemiology
- descriptive
- analytical
- intervention
what is prevalence
- number of disease cases in a population at a given time
- = (number of affected individuals)/(total number of persons in population)
what is prevalence good for measuring
- chronic diseases
what can prevalence do
- relate attributes to absence/presence of disease
- development of a hypothesis
what is incidence
- number of new disease cases developing over a specific period of time in a defined population
- = (number of new cases of disease in a period of time)/(number of individuals in the population at risk)
what is incidence good for measuring
- cancer
what is distribution
- how common is X
- based on = time, place, person OR, when, where and who
why do we need epidemiological indices
- to measure disease an appropriate index is needed
what are the properties of an ideal epidemiological index
- clear, unambiguous, objective not subjective
- correspond with clinically important stages of disease
indicate treatment need - within the ability of examiners
- reproducible
- not time-consuming
- acceptable to patient
- amenable to statistical analysis
- allow comparison with other studies
what is the DMF index
- for permanent teeth
- DMFT = decayed, missing and filled teeth = 0-32
- DMFS = decayed, missing and filled surfaces = 0-148
what is the dmf index
- for deciduous teeth
- dmft = decayed, missing and filled teeth = 0-20
- ‘e’ is indicated for extraction or exfoliated tooth
what does D3MFT/d3mft or D1MFT/d1mft mean
- d1 = decay into enamel
- d3 = decayed into dentine
what is extensive decay mean
- lesion is into the pulp
what is moderate decay
- clinically detectable lesions into dentine
- clinically detectable cavities limited to enamel
what is initial decay
- clinically detectable enamel lesions with intact surfaces
what is very early decay
- small lesions detectable only with additional diagnostic aids
- sub-clinical initial lesions in a dynamic state of progression/regression
what are the limitations of the DMF/dmf index
- teeth are extracted for reasons other than caries
- influenced by access
- difficulty in differentiating fissure-sealant from restorations
- influenced by past disease activity
- cannot be used for root caries
what does D/DMF give you
- indication of treatment need
what does F/DMF give you
- indication of treatment provision
- the ‘care’ index
what does M/DMF give you
- indication of treatment failure
what is NDIP
- national dental inspection programme
what is detailed NDIP
- epidemiology
- high level planning.evaluation of interventions
what is basic NDIP
- monitoring
- targeting interventions
- informing parents/children oral health status and need for dental services
who gets a detailed NDIP and who gets basic
- every child must have basic
- alternate yearly between P1 and P7 for detailed
what is the average dmft
- around 1 now
what is the average percentage of children with decay
- around 45%
- dmft = 4-5
what do adult dental health surveys measure
- total tooth loss, number of teeth and infection
- condition of natural teeth, restorative treatment and supporting structures
- social and behavioural characteristics and oral health
- trends in tooth loss and the condition of natural teeth
- dental attitudes and reported behaviour
- reports by country
how is periodontal disease measured
- plaque indices = debris index, plaque index
- gingivitis indices = modified gingival index, Lorene index
- periodontitis indices = CPITN/BPE
