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Description about Mortality and its Determinents

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  1. 1. - RAM NAIK. M 4 th Semester
  2. 2. The scope of measurement is very broad and unlimited and includes <ul><li>Measurement of mortality. </li></ul><ul><li>Measurement of morbidity. </li></ul><ul><li>Measurement of disability. </li></ul><ul><li>Measurement of natality. </li></ul><ul><li>Measurement of presence, absence or distribution of the characteristic of disease. </li></ul><ul><li>Measurement of medical needs, health care facilities, utilization of health services. </li></ul><ul><li>Measurement of demographic variables. </li></ul>
  3. 3. Tools of measurement <ul><li>Rate </li></ul><ul><li>Ratio </li></ul><ul><li>Proportions </li></ul>
  4. 4. RATE <ul><li>A rate measures the occurrence of some particular event in a population during a given period of time. </li></ul><ul><li>Death rate= </li></ul><ul><li>It has 3 categories </li></ul>Number of deaths in one year Mid-year population X 1000
  5. 5. <ul><li>CRUDE RATES : </li></ul><ul><li>These are the actual observed rates such as death rates and birth rates. These also known as unstandardized rates. </li></ul><ul><li>SPECIFIC RATES : </li></ul><ul><li>These are the actual observed rates due to specific cause; or occurring in specific groups or during specific time periods. </li></ul><ul><li>STANDARDIZED RATES : </li></ul><ul><li>These are obtained by direct or indirect method of standardization or adjustment </li></ul>
  6. 6. RATIO <ul><li>It expresses a relation in size between two random quantities. </li></ul><ul><li>The numerator and denominator may involve an interval of time or may be instantaneous in time </li></ul><ul><li>Expressed in the form of X:Y or </li></ul><ul><li>Ex: </li></ul><ul><li>The ratio ratio of WBC and RBC is 1/600. </li></ul><ul><li>Sex ratio </li></ul><ul><li>Doctor-population ratio </li></ul>X Y
  7. 7. PROPORTION <ul><li>It is a ratio which indicates the relation in magnitude of a part of a whole. </li></ul><ul><li>The numerator is always included in the denominator. </li></ul><ul><li>Ex: </li></ul>Number of children with scabies at certain time Total number of children in the village at same time X 100
  9. 9. Definition:- <ul><li>Mortality is a term which means “death” or describes death and related issues </li></ul>
  10. 11. <ul><li>National vital registration systems </li></ul><ul><li>(advanced countries) </li></ul><ul><li>Sample registration systems </li></ul><ul><li>(China and India) </li></ul><ul><li>Household surveys </li></ul><ul><li>(to estimate infant and child mortality) </li></ul><ul><li>Special longitudinal investigations </li></ul><ul><li>(maternal mortality studies) </li></ul>Major sources of mortality information
  11. 12. Limitations of mortality data <ul><li>Incomplete reporting of deaths </li></ul><ul><li>Lack of accuracy </li></ul><ul><li>Lack of uniformity-hampers the national and international comparability. </li></ul><ul><li>Choosing a single cause of death -only underlying cause leaving the risk factors. </li></ul><ul><li>Changing coding systems and changing fashion in diagnosis- affect the validity </li></ul><ul><li>Disease with low fatality </li></ul>
  12. 13. Uses of mortality data <ul><li>Employed in explaining trends and differentials in overall mortality </li></ul><ul><li>Clues for epidemiological research </li></ul><ul><li>Assessment and monitoring of public health problems and programmes </li></ul>
  13. 14. Crude death rate Specific death rate Case fatality rate Proportion mortality rate Survival rate Adjusted/Standardized rates Mortality rates and ratios
  14. 15. CRUDE DEATH RATE <ul><li>Is the simplest measure of mortality. </li></ul><ul><li>The number of deaths (from all </li></ul><ul><li>causes) per 1000 estimated mid-year population </li></ul><ul><li>in one year in a given place . </li></ul><ul><li>Disadvantage : </li></ul><ul><li>They lack comparability for with communities in a population that differ by age, sex, race…. </li></ul>Number of deaths during the year Mid-year population X 1000
  15. 16. Components: <ul><li>A specified measurement period. </li></ul><ul><li>The numerator, the number of deaths that occurred in a specified geographic area during a given period of time, and </li></ul><ul><li>The denominator, the total number of people in the population at risk in the same geographic area for the same period of time (&quot;person-years at risk&quot;) . </li></ul><ul><li>A constant. The result of the fraction is usually multiplied by some factor of 10 (such as 1000) , so that the rate may be expressed as a whole number. </li></ul>
  16. 17. SPECIFIC DEATH RATES <ul><li>May be </li></ul><ul><li>Cause or disease specific </li></ul><ul><li>Related to specific groups: age-specific, sex-specific, age and sex specific </li></ul><ul><li>Helps us to identify particular group(s) ‘ at risk ’ for preventive action. </li></ul>
  17. 19. Advantages : <ul><li>Can compare mortality at different ages </li></ul><ul><li>Can compare mortality in the same age groups over time and/or between countries and areas </li></ul><ul><li>Can be used to calculate life tables to create an age-independent measure of mortality (life-expectancy) </li></ul>
  18. 20. CASE FATALITY RATE <ul><li>The proportion of people with a disease who dies from that disease during a time period that usually corresponds to the duration of the disease. </li></ul><ul><li>Disadvantages : </li></ul><ul><li>Limited to acute diseases (since period between onset to death is long and variable in chronic diseases) </li></ul><ul><li>CFR for same disease may vary in different epidemics due to altering agent, host, environmental factors </li></ul>Total deaths due to particular cause Total cases due to the same disease X 100
  19. 21. PROPORTIONAL MORTALITY RATE/RATIO <ul><li>Indicates the number of deaths due to particular cause per 100 total deaths. </li></ul><ul><li>Disadvantages : </li></ul><ul><li>Does not indicate the risk of members of population dying from that disease. </li></ul><ul><li>It is of limited value in comparison as it depends on two variables, both of which may alter. </li></ul>Number of deaths from a specific cause in a year Total deaths from all causes in that year X 100
  20. 22. SURVIVAL RATE <ul><li>It is the proportion of survivors in a group studied and followed over a period of time. </li></ul><ul><li>It is a method of describing the prognosis in certain disease conditions. </li></ul>Total number of patients alive after 5 years Total number of patients treated X 100
  21. 23. ADJUSTED / STANDARDIZED RATES <ul><li>Advantages : </li></ul><ul><li>Removes the confounding effect of different age structures and yields a single standardized rate, through which mortality rates can be compared directly </li></ul><ul><li>Methods : </li></ul><ul><li>Direct standardization </li></ul><ul><li>Indirect standardization. </li></ul>
  22. 24. THANK YOU