community diagnosis

بسم الله الرحمن الرحيم

Community Diagnosis

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 - incidence rates, including attack rate.
b- prevalence rates (point and period prevalence).
c- measure the main morbidity and mortality rates in addition to fertility rates.

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.

• Tools of measurements:

• Every component of a study e.g. a disease, an exposure, an event ( e.g. Birth, death) must be defined and measured. These measures are used in assessment of health problems in the community, that will aid in planning and evaluation of the effective health programs for disease control and prevention. Certain tools are used for this purpose. Such as:
• Rates, ratios and proportion


N
Rate = ــــــــــــ x K
D
e.g. crude death rate in an area = 15/1000 population in 2000 in an area.
N
ـــــــــــــRatio =
D
e.g. male to female ratio = is 3:1
N
ــــــــــــ Proportion =
D
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.

• There are three major demographic events occur in any population include fertility, mortality & morbidity, thus we will talk about the most important measurements of each event.
• Measures of Fertility:
• No. of Live births during one year

II. Measures of mortality: Mortality rates are of many types:1. Crude death rate (CDR): is the total number of deaths (all ages, both sexes and all causes) divided by the total population during a specific period of time.
Total deaths (all ages, both sexes, all causes)
CDR= ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ × 1000
Mid year population
. CDR represents the actual experience of the population.
. It Provides data useful for public health planning and administration.
. Widely used for comparison purposes.
. Easy to calculate.


Natural Growth Rate = CBR – CDR (usually in %).
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%.

• No. of live births - No. of deaths in one year

• Natural Growth Rate = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 100
• Mid year population
2. Category specific mortality rates:
They are calculated among categories of the population defined on the basis of particular characteristics (e.g. age, sex, race, cause….etc). E.g.
Deaths in a specific age-group during one year
1. Age-Specific Death Rate = ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
Population in a specific age-group

Deaths among infants (1 year of age) during one year

a- Infant Mortality Rate = ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
Total live births

Infant mortality rate (IMR) = Neonatal mortality rate (NMR) + Post neonatal mortality rate (PNMR).

• Deaths among neonates (<4 weeks of age) during one year

• *NMR = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
• Total live births
• Deaths among infants after neonatal period
• (>28 days-1year) during one year
• *Post NMR = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
• Total live births
Deaths among children (<5 years of age)
during one year
b- <5 MR = ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
Total live births


• Deaths at specific age & sex group during
• one year
• 2- Age & Sex Specific MR= ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
• Total population of the same age & sex
• Or other combinations.
Deaths due to specific cause during one year
3- Cause Specific MR = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
Total population at risk of getting the disease

. Cause specific mortality rate is a measure of risk of death from certain diseases.

• 3.Case fatality rate:
• Deaths due to specific cause during one year
• Case fatality rate = ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 100
• Total no. of cases of that disease in that period of time
• . 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.
4. Proportional mortality:
No. of deaths from a specific cause
in a specific year
Proportional mortality = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 100
Total no. of deaths in that year

. It is NOT a rate, it is proportion expressed in %.
. Tells nothing about risk (to tell risk use mortality rate).


• 5. Maternal mortality ratio:
• Maternal deaths ( during pregnancy, labour
• and puerperium ) in one year
• MMR = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــx 1000
• Total births (stillbirths + live births)
• 6. Stillbirth rate:
• No. of stillbirths during one year
• Stillbirth rate = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
• Total births (stillbirths + live births)
• 7. Perinatal mortality rate:
• (stillbirths + deaths in the 1st week of life)
• during one year
• PMR = ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ x 1000
• Total births (stillbirths + live births)