1. Dr Qurat ul ain MBBS , MD , diploma in clinical Research (USA)
Mortality Indicators
Dr Qurat ul ain
MBBS , MD , diploma in clinical Research (USA)

2. Objectives for the session students should be able to
Define mortality indictors
Enumerate various mortality indicators
Describe some important mortality indicators

3. Indicator : Indicates a situations Index : plural of indicator
Mortality is a term which means “death” or describes death and related issues
Indicator : Indicates a situations
Index : plural of indicator

4. Mortality Table

5. Three Levels of Rates
Crude rates
Specific rates/ratios
Adjusted rates

6. Crude rates

7. CRUDE Death Rates “General” (crude) mortality rate
a population group exposed to risk of death
a time period
Crude Mortality Rate = # of deaths occurring in that population during that period of time

8. Crude Death Rates
Does NOT account for differences of age, sex, etc. in any aspect of death
Info needed:
total deaths
total population
a given period of time
SIMPLEST

9. Crude Death Rates

10. Disadvantage
Lack of comparability when two vary ( with respect to age , sex , race etc.)

11. Specific rates used especially when we have to throw light on etiology
Specific to a cause eg: specific deaths due to tuberculosis ,,,HIV/AIDS
Specific to groups : like age sex , race
Advantage : allows comparability

12. Cause Specific Mortality Rate

13. Cause Specific Mortality Rate

14. Case Fatality Rate
Killing power of a disease (how fatal a diseases can be )
It ratio of deaths to cases
For acute cases
Cannot be used for chronic diseases

15. Case Fatality Rate

16. Specific Death Rates for different ages
For example: infant mortality

18. Adjusted rates

19. Adjusted rates are more reliable as they avoid the confounding variables like age and sex etc
Most common method of adjustment are
Direct standardization
Indirect standardization

20. For standardizing we need to have a standard population who age and sex composition is known
Direct standardization is used whenever stable stratum- specific rates are available
Indirect standardization is used when stratum-specific rates are unavailable or unstable because of small numbers

21. Standardization is a method of adjustment
Standardization is a method of adjustment. This is generally done for age differentials but can also be done for other factors.
The objective is to remove the effect of differential mortality or differential structure of the subgroups in the two populations under comparison.
The rates are then brought to a common base and thus made comparable.

22. Two methods of standardization are in use
Two methods of standardization are in use. Both require assumption of a Standard or a reference population.
This could be real or hypothetical, but in both cases the standard is arbitrary.
In case of age standardization, the standard may have a predefined age structure or a predefined ASDR( age specific death rate).
These two methods of standardization can give entirely different results.

24. Indirect standardization

25. When stratum-specific numbers are small, stratum-specific rate estimates are too susceptible to being heavily influenced by random variability for the direct standardization method to be satisfactory.
Instead, an "indirect" standardization procedure is often used and a "standardized mortality ratio" ("SMR") computed. (The standard mortality difference, computed as the indirectly standardized rate minus the crude rate from the standard population, is also theoretically of interest).
Indirect standardization avoids the problem of imprecise estimates of stratum-specific rates in a study population by taking stratum-specific rates from a standard population of sufficient size and relevance.

26. These rates are then averaged using as weights the stratum sizes of the study population
Thus, the procedure is the mirror-image of direct standardization.
In direct standardization, the study population provides the rates and the standard population provides the weights
In indirect standardization, the standard population provides the rates and the study population provides the weights

27. Standardized Mortality Ratio (SMR)

29. Thank you

30. THANKS