Community Diagnosis
بسم اهلل الرحمن الرحيم
Community Diagnosis:
It is the process of identifying the main health
problems that affect the community regarding its
health, social and economic development.
This process is conducted through collection, analysis
and interpretation of data, using the main tools of
measurements. Furthermore, these results will be used
for the planning and evaluation of the effective health
programs for the control and prevention of diseases.
Instructional objectives
At the end of the lecture students would be able to:
1- Calculate and interpret the differences between
rates, ratios & proportions.
2- Estimate and assess the importance of:
a-
Measure the main morbidity and mortality rates
in addition to fertility rates.
b-
Incidence rates, including attack rate.
c-
Prevalence rates (point and period prevalence).
• Tools of Community Diagnosis:
The Tools of community diagnosis mainly
comprises various Rates and Ratios.
The Rate (R) is defined as:
Where:
N: No. of times an event has occurred during a
specific time interval (as the Numerator).
D: No. of persons exposed to the risk of the event
during that same time (as the Denominator).
(N is a part of D).
K: Around no. (100, 1000, 10000
… etc.) depending
upon the relative magnitude.
K
R
D
N
*
The Ratio R` is defined as:
Where:
:No. of events or times counted and not
necessarily a part of (as the Numerator).
:No. of events or times counted and not
necessarily a population of persons exposed
to risk (as the Denominator)
When: N is a part of D it is called a
Proportion
Where:
K
R
D
N
*
N
D
D
N
P
e.g. crude death rate in an area = 15/1000 population
in 2000 in an area.
e.g. male to female ratio = is 3:1
e.g. proportion of deaths due to ischemic heart disease
among all deaths is 25%.
These tools could be used for diseases or deaths or
births or any health related problem.
K
D
N
*
Rate
D
N
o
Rati
D
N
Proportion
1.
Measures of Fertility:
K
*
Year
-
Mid
at the
Population
Total
Year
One
During
Births
-
Live
No.of
Rate
Birth
1.Crude
K
*
49)Years
(15
Age
of
Population
Female
No.of
Year
One
During
Births
Live
of
No.
Rate
Fertility
2.General
Crude Birth Rate (CBR) :
General Fetility Rate (GFR) :
e.g.
An area has: CBR = 39.6 births/1000 population and
CDR = 10.5 deaths/1000 population, so:
Natural Growth Rate = 39.6 - 10.5 = 29.1/1000 population,
or = 2.9%
or
100
*
population
year
Mid
year
one
in
deaths)
of
No.
-
births
live
of
(No.
Rate(NGR)
Growth
Natural
%)
in
(usually
CDR
–
CBR
(NGR)
Rate
Growth
Natural
Natural Growth Rate (NGR) :
2.
Measures of Mortality :
K
*
Year
-
Mid
at the
Population
Total
Year
One
During
Deaths
No.of
Total
Rate
Death
Crude
1.
K
*
Year
-
M id
at the
Group
Specific
In the
Population
Total
Year
One
During
Group
Specific
a
In
Deaths
No.of
Total
Rate
Death
Specific
2.
K
*
Year
That
at
Births
-
Live
Total
Year
One
In
Year)
1
(Under
Infants
Among
Deaths
No.of
Total
Rate
M ortality
Infant
3.
Crude Death Rate (CDR) :
Specific Death Rate (SDR) :
Infant Mortality Rate (IMR) :
K
*
Year
That
at
Births
-
Live
Total
Year
-
One
In
M onths)
12
1
(From
Infant
Among
Deaths
No.of
Total
Rate
M ortality
Neonatal
-
Post
7.
K
*
Year
That
at
Births
-
Live
Total
Year
-
One
In
Age)
of
Days
28
7
(From
Deaths
of
No.
Total
Rate
Mortality
Neonatal
-
Late
6.
K
*
Year
That
at
Births
-
Live
Total
Year
-
One
In
Age)
of
Days
7
(Under
Deaths
No.of
Total
Rate
M ortality
Neonatal
-
Early
5.
K
*
Year
That
at
Births
-
Live
Total
Year
-
One
In
Age)
of
Days
28
(Under
Neonates
Among
Deaths
No.of
Total
Rate
M ortality
Neonatal
4.
Neonatal Mortality Rate (NMR) :
Early Neonatal Mortality Rate (ENMR) :
Late Neonatal Mortality Rate (LNMR) :
Post Neonatal Mortality Rate (PNMR) :
K
*
Year
That
at
Live)
(Still
Births
Total
Year
-
One
In
Age)
of
Days
7
(Under
Deaths
s
StillBirth
No.of
Rate
M ortality
Perinatal
8.
K
*
Year
That
at
Live)
(Still
Births
Total
Year
-
One
In
s
StillBirth
No.of
Rate
StillBirth
9.
K
*
Year
That
at
Years
49)
-
(15
Age
g
Childearin
in
Women
of
No.
Total
OneYear
In
)
Puerperium
and
Delivary
,
(Pregnancy
to
Due
Mothers
of
Deaths
No.of
Rate
Mortality
Maternal
10.
K
*
Year
That
at
Live)
(Still
Births
Total
OneYear
In
)
Puerperium
and
Delivary
,
(Pregnancy
to
Due
Mothers
of
Deaths
No.of
o
Rati
Mortality
Maternal
11.
Perinatal Mortality Rate (PMR) :
Still Birth Rate (SBR) :
Maternal Mortality Rate (MMR) :
Maternal Mortality Ratio' (MMR') :
K
*
Year
That
During
Causes
All
to
Due
Deathes
of
No.
Total
Year
One
During
Cause
Specific
to
Due
Deaths
No.of
Total
o
Rati
Death
of
13.Cause
Denominator is limited to those already having disease NOT
the whole population.
It is a measure of disease severity.
Usually in %.
Can measure the effectiveness of a new treatment.
K
*
Disease
the
Getting
of
Risk
at
Population
Total
Year
One
During
Cause
Specific
to
Due
Deaths
No.of
Rate
Death
Specific
Cause
12.
K
*
Time
of
Period
That
in
Disease
That
of
Cases
of
No.
Total
Year
One
During
Cause
Specific
to
Due
Deaths
No.of
Total
Rate
Faitality
14.Case
Cause Specific Death Rate (CSDR) :
Cause of Death Ratio' (CDR') :
Case Fatality Ratie (CFR) :
It is NOT a rate, it is proportion expressed in %.
Tells nothing about risk (to tell risk use mortality rate).
Under Five Mortality Rate (U5 MR):
100
*
Year
Same
The
in
Ages
All
in
Deaths
No.of
Total
Year
Specific
a
in
Year)
50
Over
Year,
1
(Under
Group
Age
Specific
a
in
Deaths
of
No.
o
Rati
Mortality
ional
15.Proport
K
*
Year
Same
The
in
Birth
Live
Total
Year
One
During
Age)
of
Years
5
(
Children
Among
Deaths
of
No.
Rate
Mortality
Five
Under
16.
Proportional Mortality Ratio' (PMR') :
ENMR = Deaths Under (7) Days of Age
LNMR = Deaths From (7-28) Days of Age
NMR = Deaths Under (28) Days of Age
PNMR = Deaths From (28-365) Days of Age
IMR = Deaths Under (1) Year of Age
U5 MR =Deaths Under (5) Years of Age
Live B
irth
• IMR = NMR + PNMR
• NMR = ENMR + LNMR
PMR = Stillbirth + ENM
SBR = Stillbirth
MMR' = Mother Death Due to (Pregnancy,
Delivery and Puerperium)
T
ot
al
Birth
2. Category Specific Mortality Rates:
They are calculated among categories of the population defined on
the basis of particular characteristics (e.g. age, sex, cause, race,
….etc). e.g.
Age-Specific Death Rate (ASDR):
Deaths in a specific age-group during one year
Age Specific Death Rate = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
Population in a specific age-group
3.
Measures of Morbidity :
K
*
Time
of
Point
That
at
Disease
of
Risk
to
Exposed
Population
Total
Time
of
Point
a
at
Existing
Cases
Old)
&
(New
All
No.of
Rate
Prevalence
Point
a.
1. Prevalence Rate (PR):
K
*
Disease
That
of
Risk
at the
Population
Total
Time
of
Period
a
During
Occuring
Disease
Specified
of
Cases
Old)
or
(New
All
No.of
Rate
Prevalence
Period
b.
Point Prevalence Rate (PPR):
Period Prevalence Rate (PPR):
Relation between Incidence & Prevalence:
Prevalence rate is influenced by both the incidence of disease and
its duration. It sometimes approximates the incidence rate if the
course of disease is short.
Prevalence = Incidence × Duration of Disease
P = I × D
Incidence Rate (IR):
K
*
Disease
That
of
Risk
the
to
Exposed
Year
Mid
at the
Population
Total
Time
of
Period
a
During
Disease
Specified
Cases)of
(New
No.of
Rate
Incidence
2.
Attack Rate (AR):
Is an incidence rate during a limited time period. For infectious
diseases, the attack rate is the number of secondary cases
occurring within the accepted incubation period divided by the
number of susceptible individuals in a closed group exposed to
the primary (index) case.
1000
*
event
that
getting
of
risk
at
Population
Total
Period
Time
limited
a
During
Occurring
Events
New
of
No.
Rate
Attack
3.