Measurement Epidemiology Methods of Measurement Epidemiology

1. PRESENTED BY,
MR. KAILASH NAGAR
ASSIST. PROF.
DEPT. OF COMMUNITY HEALTH NSG.
DINSHA PATEL COLLEGE OF NURSING, NADIAD

2.  Mortality.
 Morbidity.
 Disability.
 Presence & absence or distribution of..
 Medical needs.
 Utilization of health services.
 Demographic variables.

3. Rate
Ratio
Proportion

4.  Measures the occurrence of an event or
disease in a given population during a given
period (one Year).
(Birth rate, growth rate, accident rate)
 Usually expressed per 100 or per1000
population.
 It has a time dimension, whereas a
PROPORTION does not.

5.  A fraction is made up of 2 numbers.
 The top number is called the
NUMERATOR
 and the bottom number is called the
DENOMINATOR.
 In the fraction ¾ the 3 is the numerator
and the 4 is the denominator.

6. No of death in one year
•  Death
rate= -------------------- X 1000
• Total mid year population
•Numerator
Denominator.
Time
specification
Multiplier
• (Numerator is part of denominator )

7.  The value obtained by dividing one
quantity by another- X/Y.
 Male to female ratio.
 A ratio often compares two rates,
death rates for women and men at a
given age.

8.  Ratio also expresses relation of size
between the two quantities.
 Numerator is not part of Denominator.
 Expressed as X / Y.
Doctor : Population ratio.
Male : Female ratio.
WBC : RBC ratio

9.  A part/share or number considered in
comparative relation to a whole.
 "the proportion of greenhouse gases
in the atmosphere is rising”
 Usually expressed as a percentage %

10.  This is also relation /magnitude between
two quantities, And numerator is always
part of denominator.
 And expressed as percentage
-Proportion of female students .
-Proportion of anemic mothers
(60% mothers are anemic)

12. Incidence
Occurrence of new cases
•
Prevalence
Existence of all new & old cases.

13.  Prevalence:- how many people in
a population currently have the
disease (Photograph)
 Incidence:- how many people are
diagnosed each year (Film)

14. Cure rate

15. New cases

16. • The rate at which acute
disease is spreading --
used during epidemics
& expressed in %.
Attack rate
• % of exposed persons
developing disease after
primary case exposure
Secondary
attack rate

17. •Prevalence at any
given point of time.
• 4% TB cases on 1st April
Point
prevalence
•Prevalence at a given
period of time.
•Period will be 1year.
Period
prevalence

18.  Longer duration of the disease.
 Prolongation of life, with treatment.
 If incidence increases.
 Immigration of new cases.
 Better reporting of cases.


19. Longer
duration of
disease
Incidence
increases.
Prolongation
of life
without
cure.
20

20.  Shorter duration of diseases.
 Improved cure rate.
 Incidence decreases.
 Emigration of new cases.
 Under reporting of cases.

21. Improved cure rate.
Short duration of
disease.
Incidence decreases

23.  Crude Death Rate.
 Specific death rate.
 Case fatality rate.
 Proportional mortality rate.
 Survival rate.
 Standardized death rate.

24.  Number of deaths from all causes, per 1000
estimated mid year population in one year in
a given place.
No deaths during one year
CDR = X 1000
Mid year population

25.  Cause Specific death ratelike
disease death rate, Road accident…
 Age specific-IMR, Child Mortality rate
 Sex specific death rate – MMR/female
 Period specific death rate–Death in May

26.  Percentage of particular cases dying
during particular disease epidemic.
 Killing power of disease particularly
acute diseases
No of deaths due to cholera
 CFR= ----------------------- X 100
Total No of cholera cases

27.  Proportion or % of deaths due to particular
cause out of total deaths.
 It measures the disease burden.
 Under 5,
proportional =
mortality rate
No of deaths below 5 years
-------------------- X 100
Total No all of deaths

28.  Percentage of the treated patients remaining
alive at the end of 5 years treatment.
 Yard stick for assessing the standard of
therapy in cancer.

Sur
vival
Rate
pts alive at the end of 5 yrs
= ---------------------- X 100
Total No of pts treated

29.  CDR can not be useful for comparison.
 Death rate need to be standardized
for comparisons.
 Standardization can be done by-
:adjusting death rate age wise,
:also can be done sex/race wise