epidemiologi2- k3

7/28/2019 EPIDEMIOLOGI2- K3

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EPIDEMIOLOGI K3

2

TJIPTO S


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KONSEP ANGKA (NUMBERS)

Absolute number

Percentage

Proportion Ratio

Rate

Apa arti masing2 angka tersebut ?


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Measurement of health and

disease is required for Preventing disease

Promoting health

Planning health services

The central tool of epidemiology is the comparisonof Rates

Absolute number

Percentage

Ratio Proportion

RATE


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Level of prevention

Primary prevention :

1.Health promotion

2.Specific protection Secundary prevention :

1.Early diagnosis & prompt treatment

2.Disability limitation Tertiary prevention:

1.Rehabilitation


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INCIDENCE RATE

The Rate at which new events occur in a

population

number of persons who contract the disease in a

specified period

I = X 10n

Sum of the length of time each person in the pop.

at risk of contracting in the disease


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Prevalence Rate is defined as

The proportion of the population at risk

affected by a disease at a specific point in

time

Number of people with the disease or condition

at a specific time

P = x 10n

Number of people in the population at risk

at the specific time


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Factors influencing observed

prevalence rate

Increased by : Decreased by:

.longer duration of the disease . shorter duration of disease

.prolongation of life of patients . high case fatality rate fromwithout care disease

. Increase in new cases . Decrease in new cases

. In-migration on cases . In-migration of healthy people

. Out-migration of healthy people . Out-migration of cases

. In-migration of susceptible . Improved cure rate of cases

people

. Improved diagnostic facilities


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Accident Rates

Accident Frequency Rate: AFR

Number of loss time accident

AFR = x 10n

Total Man hour

Accident Severity Rate : ASRNumber of days lost

ASR = x10n

Total Man Hour

Accident Incidence Rate

Number of loss time accidentAIR = x10n

Pop. at risk


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Sentinel

Incidence rate of days away from work =

number of days away from work x 200.000

employee hours

Vehicle accident rate =

number of accident x 1000.000vehicle miles or kilometers


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Safe-T-Score

freq.rate now freq.rate past

Safe-T-Score = -----------------------------------freq.rate past

million worker-hours now

Note:

Safe-T-Score >+2 ; worse than it was in the previous period

Safe -T-Score < - 2 : better than it was in the last periodSafe-T-Score is between +2 and 2 the change is not

significantly different


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Home work

Location x: last year 10 accidents, 10.000worker-hours , freq. rate = 1000.

This year 15 accidents, 10.000 worker-hours,

freq. rate= 1500 Location y: last year 10.000 accidents,

1,000,000 worker-hours, freq. rate = 1000

This year 1,100 accidents, 1,000,000 worker-

hours, freq. rate = 1,100 Has something gone wrong at one or both

location?


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Home workParticular Year 2009

No. of no lost time accident (NLTA)

No. of lost time accident (LTA)

Total number of days lost

Average number of workers

Estimated total man hours

Total Number of accident

Accident Incident Rate

Accident Frequency Rate

Accident Severity Rate

Number of days charged per case

200

61

450

2.725

7.525.790

? 200+61

?61:2725

?61:7525790

?450:7525790

? 450:61


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Screening test

Kanker paru

Hasil test ya Tidak total

positip 150 300 450

negatip 50 99500 99550

total 200 99800 100000

Sensitivity = 150/200 = 75%

Specificity= 99500/99800 = 99%

Predictive value positive= 150/450 =33%

epidemiologi2- k3

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