Ce diaporama a bien été signalé.
Nous utilisons votre profil LinkedIn et vos données d’activité pour vous proposer des publicités personnalisées et pertinentes. Vous pouvez changer vos préférences de publicités à tout moment.
Measures of Morbidity and Mortality<br />Akhilesh Bhargava<br />MD, DHA, PGDHRM<br />Professor-Community Medicine<br />& D...
Akhilesh Bhargava<br />2<br />The fundamental task in epidemiologic research is to quantify the occurrence of illness<br /...
Akhilesh Bhargava<br />3<br />What is a rate?<br />“a measure of speed with which events are occurring in a population in ...
Akhilesh Bhargava<br />4<br />Why a rate?<br />To ensure comparing apples with apples<br />
Akhilesh Bhargava<br />5<br />Prevalence VS. Incidence<br />Prevalence:<br />	A “snapshot” of disease at a point in time i...
Akhilesh Bhargava<br />6<br />Prevalence (P) and Incidence (I)<br />P~I x d<br />d=duration<br />P= I x d<br />If the dise...
Akhilesh Bhargava<br />7<br />Prevalence<br />          number of individuals with the disease<br /> P = -----------------...
Akhilesh Bhargava<br />8<br />Prevalence: Example<br />A sample of 1,000 women 70-74 years.  70 were<br />found to have th...
Akhilesh Bhargava<br />9<br />Prevalence<br />   Choice of scale of rate usually depends on the ubiquity of the disease.<b...
Akhilesh Bhargava<br />10<br />Incidence Rate: Example<br />In 1973 there were 29 cases of MI in Jaipur among men 40-44 ye...
Akhilesh Bhargava<br />11<br />Incidence Rate<br />    No. of new cases occurring during a period of time<br />I =--------...
Akhilesh Bhargava<br />12<br />“Total Person Time”<br /> Sum of person time of all individuals at risk<br />Equivalence of...
Akhilesh Bhargava<br />13<br />N= 300<br />Case no.<br />1<br />2<br />R<br />3<br />4<br />5<br />R<br />6<br />July 30, ...
Akhilesh Bhargava<br />14<br />Crude and Specific Rates<br />“Crude”:  Rates calculated for the “entire” population<br />“...
Akhilesh Bhargava<br />15<br />Comparing Apples with Apples<br />In comparing populations (groups) one<br />should recogni...
Akhilesh Bhargava<br />16<br />Comparison of Death rates in two population by age<br /><ul><li>No difference in two popula...
Population  A has higher crude death rate for large aged pop.
CDR may not always reflect risk of death in a comparative study</li></li></ul><li>Akhilesh Bhargava<br />17<br />Standardi...
Akhilesh Bhargava<br />18<br />Adjusted Rates are Created Through Standardization<br />Standardization: The process by whi...
Akhilesh Bhargava<br />19<br />Direct Adjustment<br />   Rates of populations to be compared applied to the standard popul...
Akhilesh Bhargava<br />20<br />           Example:  Age-Adjustment <br />Direct Method requires -<br />Age-specific rates ...
Akhilesh Bhargava<br />21<br />Calculation of expected no of deaths by direct method: Same age specific rates<br /><ul><li...
Risk of death is identical in Pop. A & B
Age adjustment has removed distortion in risk of death from crude death rate</li></li></ul><li>Akhilesh Bhargava<br />22<b...
Akhilesh Bhargava<br />23<br />Direct Age Adjustment<br />
Akhilesh Bhargava<br />24<br />Direct Age Adjustment:Comparison of Age specific death rates<br />
Akhilesh Bhargava<br />25<br />Direct Age Adjustment:Age adjustment using total of two pop. As standard<br />22381830<br /...
Akhilesh Bhargava<br />26<br />Indirect Adjustment<br />    Rates of standard population applied to populations to be comp...
Akhilesh Bhargava<br />27<br />Indirect method requires <br />Age structure (percentage of cases in each age group) of the...
Akhilesh Bhargava<br />28<br />Indirect Standardization<br />Instead of a standard population structure, you utilize a sta...
Akhilesh Bhargava<br />30<br />Indirect Standardization (cont.)<br />
Akhilesh Bhargava<br />31<br />Indirect Standardization (cont.)<br />    Some individuals contribute different amounts of ...
Vital Statistics<br />
Akhilesh Bhargava<br />33<br />Indicators of Public Health<br />Mortality statistics<br />Age specific mortality rates<br ...
Akhilesh Bhargava<br />34<br />Vital Statistics<br />Systems for collecting vital statistics<br />Civil registration syste...
Akhilesh Bhargava<br />35<br />Vital Statistics<br />Priority in Vital Statistics Collection – based on UN criteria<br />B...
Akhilesh Bhargava<br />36<br />Vital Statistics<br />Legal documentation<br />Assessment <br />Demography<br />Health<br />
Akhilesh Bhargava<br />37<br />Vital Statistics<br />History <br />U.S. census every 10 years since 1790<br />Mid-point ce...
Akhilesh Bhargava<br />38<br />Mortality Data<br />Comprehensive<br />Measure of community health<br />Track trends over t...
Akhilesh Bhargava<br />39<br />Mortality Rate<br />Total number of deaths <br />from all causes in 1 yr<br />Annual <br />...
Akhilesh Bhargava<br />40<br />Mortality RatesAge Specific<br />Total number of deaths <br />from all causes in 1 yr<br />...
Akhilesh Bhargava<br />41<br />Mortality Rates:Disease Specific<br />Total number of deaths <br />from lung cancer in 1 yr...
Akhilesh Bhargava<br />42<br />Total and Age-Specific Mortality Rate (deaths/1000)<br />
Akhilesh Bhargava<br />43<br />Infant Mortality Rate<br />Number of deaths in a year of live-born<br />infants less than 1...
Akhilesh Bhargava<br />44<br />Source of Error in Mortality Statistics<br />Facts inaccurate<br />Demographic- age, sex, r...
Akhilesh Bhargava<br />45<br />Sources of Information<br />Deaths<br />Death certificate<br />Clinical records<br />Autops...
Akhilesh Bhargava<br />46<br />Case Fatality Rate<br />Total number of individuals <br />dying during a specified period<b...
Akhilesh Bhargava<br />47<br />Proportionate Mortality<br />Total number of deaths <br />from the Disease in given yr<br /...
Akhilesh Bhargava<br />48<br />Comparing Mortality in Different Populations<br />Crude<br />Age Adjustment<br />Direct<br ...
Akhilesh Bhargava<br />49<br />Trends in Mortality:Artifactual<br />
Akhilesh Bhargava<br />50<br />Measures of Mortality:<br />Mortality rate<br />Cause specific<br />Age specific<br />Case-...
Akhilesh Bhargava<br />51<br />Why study Mortality-<br />Eternal, ultimate experience<br />A measure of disease severity<b...
Akhilesh Bhargava<br />52<br />Mortality Data- Problems<br />Change in coding of ICD revisions<br />Changes in definitions...
Prochain SlideShare
Chargement dans…5
×

Measures of Mortality

15 975 vues

Publié le

Can be viewed at www.sihfwrajasthan.com

Publié dans : Santé & Médecine, Technologie
  • ⇒⇒⇒WRITE-MY-PAPER.net ⇐⇐⇐ has really great writers to help you get the grades you need, they are fast and do great research. Support will always contact you if there is any confusion with the requirements of your paper so they can make sure you are getting exactly what you need.
       Répondre 
    Voulez-vous vraiment ?  Oui  Non
    Votre message apparaîtra ici
  • If you’re looking for a great essay service then you should check out ⇒ www.HelpWriting.net ⇐. A friend of mine asked them to write a whole dissertation for him and he said it turned out great! Afterwards I also ordered an essay from them and I was very happy with the work I got too.
       Répondre 
    Voulez-vous vraiment ?  Oui  Non
    Votre message apparaîtra ici
  • Follow the link, new dating source: ♥♥♥ http://bit.ly/39pMlLF ♥♥♥
       Répondre 
    Voulez-vous vraiment ?  Oui  Non
    Votre message apparaîtra ici
  • Sex in your area is here: ♥♥♥ http://bit.ly/39pMlLF ♥♥♥
       Répondre 
    Voulez-vous vraiment ?  Oui  Non
    Votre message apparaîtra ici
  • respected sir plz allow me to download your presentation
       Répondre 
    Voulez-vous vraiment ?  Oui  Non
    Votre message apparaîtra ici

Measures of Mortality

  1. 1. Measures of Morbidity and Mortality<br />Akhilesh Bhargava<br />MD, DHA, PGDHRM<br />Professor-Community Medicine<br />& Director-SIHFW, Jaipur<br />
  2. 2. Akhilesh Bhargava<br />2<br />The fundamental task in epidemiologic research is to quantify the occurrence of illness<br />The goal is to evaluate causation of illness by relating disease occurrence to characteristics of people and their environment<br />Rates, Ratios, and Standardized Rates are primary tools for quantifying occurrence of illness<br />
  3. 3. Akhilesh Bhargava<br />3<br />What is a rate?<br />“a measure of speed with which events are occurring in a population in a specified time period.”<br />Essentials<br />A numerator<br />A denominator that “appropriately” relates the numerator to population at risk<br />A “unit” such as per 1000, per 100,000 or per million<br />
  4. 4. Akhilesh Bhargava<br />4<br />Why a rate?<br />To ensure comparing apples with apples<br />
  5. 5. Akhilesh Bhargava<br />5<br />Prevalence VS. Incidence<br />Prevalence:<br /> A “snapshot” of disease at a point in time in a population<br /> Relevant for planning of health services<br />Incidence:<br /> A description of how new cases of disease are occurring. “force of morbidity” “rate of flow” of cases from non disease to disease state<br /> Relevant for exploring causal theories<br />
  6. 6. Akhilesh Bhargava<br />6<br />Prevalence (P) and Incidence (I)<br />P~I x d<br />d=duration<br />P= I x d<br />If the disease is stable, that<br />is, if the incidence and <br />duration remains constant <br />over time.<br />
  7. 7. Akhilesh Bhargava<br />7<br />Prevalence<br /> number of individuals with the disease<br /> P = -----------------------------------------------------<br /> number of individuals at risk <br /> Prevalence can be expressed either as a proportion or as a rate<br /> Expressed as a proportion, prevalence is a number between 0 and 1<br /> As a rate, prevalence can be expressed as per 1000, per 100,000, or per whatever<br />
  8. 8. Akhilesh Bhargava<br />8<br />Prevalence: Example<br />A sample of 1,000 women 70-74 years. 70 were<br />found to have the diagnosis of rheumatoid arthritis.<br />The prevalence of arthritis is:<br /> 70<br />P= ------------- = 0.07 for women age 70-74<br />1,000<br />Or <br />P= 70 per thousand for women age 70-74<br />Or<br />P= 7 percent for women age 70-74<br />Or……….<br />
  9. 9. Akhilesh Bhargava<br />9<br />Prevalence<br /> Choice of scale of rate usually depends on the ubiquity of the disease.<br /> Thus, more common disease prevalence may be presented as percentage<br /> Rare disease prevalence may be presented as per 100,000 or per million<br />
  10. 10. Akhilesh Bhargava<br />10<br />Incidence Rate: Example<br />In 1973 there were 29 cases of MI in Jaipur among men 40-44 years. The number of person years was 41,532.<br />The incidence rate is:<br /> 29 <br />I = --------- =0.0007 per year<br /> 41,532<br /> = 0.7 per thousand per year<br /> = 7 per 10 thousand per year<br /> = 700 per million per year<br />To be more accurate, we must add another qualifier, namely, “for men 40-44 years of age”<br />
  11. 11. Akhilesh Bhargava<br />11<br />Incidence Rate<br /> No. of new cases occurring during a period of time<br />I =----------------------------------------------------------------<br /> “total person time” at risk<br />What is “person time”:<br /> The duration of time a person is at risk<br /> Usually expressed as person years but can be expressed as anything, e.g., person months, person weeks, etc.<br />
  12. 12. Akhilesh Bhargava<br />12<br />“Total Person Time”<br /> Sum of person time of all individuals at risk<br />Equivalence of “total person time”<br /> 50,000 person years<br /> = 5,000 persons observed for 10 years<br /> = 1,000 persons observed for 50 years<br /> = 10,000 persons observed for 5 years<br />
  13. 13. Akhilesh Bhargava<br />13<br />N= 300<br />Case no.<br />1<br />2<br />R<br />3<br />4<br />5<br />R<br />6<br />July 30, 2008<br />June30, 2009<br />Date of recurrence<br />R =<br />Date of Onset of disease<br />Date of Termination or death<br />Point prevalence on July 30, 2003= 4 cases( 1, 2, 3, 6)/ 300<br />Incidence rate on July 30, 2003= 2 cases (4, 5) /296<br />Period prevalence between July 30, 2003 to June 30, 2004= 6 /300<br />
  14. 14. Akhilesh Bhargava<br />14<br />Crude and Specific Rates<br />“Crude”: Rates calculated for the “entire” population<br />“Specific”: Rates calculated for “specific” subpopulations.<br />Ex: Age-specific rates<br /> Race-specific rates<br /> Gender-specific rates<br />
  15. 15. Akhilesh Bhargava<br />15<br />Comparing Apples with Apples<br />In comparing populations (groups) one<br />should recognize that populations (groups) <br />can differ in two important respects:<br /> Subpopulation-specific rates<br /> Distribution of subpopulations<br />
  16. 16. Akhilesh Bhargava<br />16<br />Comparison of Death rates in two population by age<br /><ul><li>No difference in two population in risk of death
  17. 17. Population A has higher crude death rate for large aged pop.
  18. 18. CDR may not always reflect risk of death in a comparative study</li></li></ul><li>Akhilesh Bhargava<br />17<br />Standardization?<br /> Standardized rate = “weighted” average of category-specific rates<br /> Standardized rates can also be called Adjusted rates. For example, age adjusted, gender adjusted, race adjusted, etc.<br />
  19. 19. Akhilesh Bhargava<br />18<br />Adjusted Rates are Created Through Standardization<br />Standardization: The process by which you derive a summary figure to compare health outcomes of groups<br />The process can be used for mortality, natality, or morbidity data<br />.<br />
  20. 20. Akhilesh Bhargava<br />19<br />Direct Adjustment<br /> Rates of populations to be compared applied to the standard population<br /> The question: What would be the number of events (deaths, births, etc.) in the standard population if events were happening at the category-specific rates in each population?<br />
  21. 21. Akhilesh Bhargava<br />20<br /> Example: Age-Adjustment <br />Direct Method requires -<br />Age-specific rates in the sample population<br />The age of each case<br />The population-at-risk for each age group in the sample<br />Age structure (percentage of cases in each age group) of a standard population<br />Summary figure is an Age-adjusted rate<br />
  22. 22. Akhilesh Bhargava<br />21<br />Calculation of expected no of deaths by direct method: Same age specific rates<br /><ul><li>While crude deaths were different, adjusted deaths are same for two pop.
  23. 23. Risk of death is identical in Pop. A & B
  24. 24. Age adjustment has removed distortion in risk of death from crude death rate</li></li></ul><li>Akhilesh Bhargava<br />22<br />Calculation of expected no of deaths by direct method: different age specific rates<br />Adjusted rate for Pop. A= 74/ 10000 X 1000= 7.4<br />Adjusted rate for Pop. B= 92/ 10000 X 1000= 9.2<br />Different risk of death in two pop. Are preserved by age adjustment <br />
  25. 25. Akhilesh Bhargava<br />23<br />Direct Age Adjustment<br />
  26. 26. Akhilesh Bhargava<br />24<br />Direct Age Adjustment:Comparison of Age specific death rates<br />
  27. 27. Akhilesh Bhargava<br />25<br />Direct Age Adjustment:Age adjustment using total of two pop. As standard<br />22381830<br />Age adjusted Rate= ---------- = 24.3 --------- =101.7<br />1800000 1800000<br />
  28. 28. Akhilesh Bhargava<br />26<br />Indirect Adjustment<br /> Rates of standard population applied to populations to be compared.<br /> The question: What would be the number of events (deaths, births, etc.) if the particular population was having events at the same category specific rates as the standard population?<br />
  29. 29. Akhilesh Bhargava<br />27<br />Indirect method requires <br />Age structure (percentage of cases in each age group) of the sample population<br />Total deaths in the sample population<br />Age-specific rates for the standard population<br />Summary figure is a<br />Standardized Mortality ratio<br />
  30. 30. Akhilesh Bhargava<br />28<br />Indirect Standardization<br />Instead of a standard population structure, you utilize a standard rate to adjust your sample<br />Indirect standardization does not require that you know the stratum-specific rates of your cases<br />The summary measure is the SMR or standardized mortality/morbidity ratio<br />Observed<br />SMR = ----------------- X 100<br /> Expected<br /><ul><li>An SMR of 100 means no difference between the number of outcomes in the sample population and that which would be expected in the standard population</li></li></ul><li>Akhilesh Bhargava<br />29<br />Indirect Standardization (cont.)<br />Total expected deaths per year: 2,083 Total observed deaths per year: 1,464<br /> SMR = 1,464 / 2,083 x 100= 70.3%<br />
  31. 31. Akhilesh Bhargava<br />30<br />Indirect Standardization (cont.)<br />
  32. 32. Akhilesh Bhargava<br />31<br />Indirect Standardization (cont.)<br /> Some individuals contribute different amounts of risk due to length of exposure<br />
  33. 33. Vital Statistics<br />
  34. 34. Akhilesh Bhargava<br />33<br />Indicators of Public Health<br />Mortality statistics<br />Age specific mortality rates<br />Disease specific mortality rates<br />Case-fatality <br />Life Expectancy<br />Maternal mortality rates<br />Infant mortality rates <br />Morbidity statistics<br />Fertility rates<br />Vaccination coverage<br />Health care utilization <br />Health status indicators<br />
  35. 35. Akhilesh Bhargava<br />34<br />Vital Statistics<br />Systems for collecting vital statistics<br />Civil registration system<br />Advocated by the United Nations<br />Present in industrialized countries<br />Costly to develop and maintain<br />Alternative methods<br />Probability area samples<br />Purposeful area samples<br />Records-based surveys<br />
  36. 36. Akhilesh Bhargava<br />35<br />Vital Statistics<br />Priority in Vital Statistics Collection – based on UN criteria<br />Births and deaths<br />Marriages<br />Divorces<br />Fetal deaths<br />Annulments<br />Judicial separations<br />adoptions<br />
  37. 37. Akhilesh Bhargava<br />36<br />Vital Statistics<br />Legal documentation<br />Assessment <br />Demography<br />Health<br />
  38. 38. Akhilesh Bhargava<br />37<br />Vital Statistics<br />History <br />U.S. census every 10 years since 1790<br />Mid-point census since 1976<br />Census <br />Latin – to estimate or assess<br />Enumerating the number of people in a given population<br />Age, sex, race, household relationships, marital status, number of rooms in house, length of time in residence, rental or ownership, value of home<br />Sampling strategies for difficult to reach populations<br />
  39. 39. Akhilesh Bhargava<br />38<br />Mortality Data<br />Comprehensive<br />Measure of community health<br />Track trends over time by region<br />Proportionate mortality<br />Infant death<br />Applies to men and women<br />Cohort analysis<br />Standardization for comparison across populations<br />Demography<br />
  40. 40. Akhilesh Bhargava<br />39<br />Mortality Rate<br />Total number of deaths <br />from all causes in 1 yr<br />Annual <br />Mortality <br />Rate<br />=<br />X 1000<br />Number of persons in the <br />population at mid-year<br />
  41. 41. Akhilesh Bhargava<br />40<br />Mortality RatesAge Specific<br />Total number of deaths <br />from all causes in 1 yr<br />per age group<br />Age-specific<br />Annual <br />Mortality <br />Rate<br />=<br />X 1000<br />Number of children in the <br />population at mid-year <br />per age group<br />
  42. 42. Akhilesh Bhargava<br />41<br />Mortality Rates:Disease Specific<br />Total number of deaths <br />from lung cancer in 1 yr<br />Annual <br />Mortality <br />Rate for <br />Lung Cancer<br />=<br />X 1000<br />Number of persons in the <br />population at mid-year<br />
  43. 43. Akhilesh Bhargava<br />42<br />Total and Age-Specific Mortality Rate (deaths/1000)<br />
  44. 44. Akhilesh Bhargava<br />43<br />Infant Mortality Rate<br />Number of deaths in a year of live-born<br />infants less than 1 year of age<br />IMR = <br />Number of live births in the same year<br />X 1000<br />
  45. 45. Akhilesh Bhargava<br />44<br />Source of Error in Mortality Statistics<br />Facts inaccurate<br />Demographic- age, sex, race, ethnicity<br />Marital status <br />Occupation<br />Place of residence, not occurrence recorded<br />Cause of death - very inaccurate <br />Immediate cause<br />Underlying condition<br />Changing taxonomy<br />
  46. 46. Akhilesh Bhargava<br />45<br />Sources of Information<br />Deaths<br />Death certificate<br />Clinical records<br />Autopsy<br />Surveillance programs<br />Village recorders<br />Population<br />Census<br />Hospital admissions<br />Fixed cohorts<br />Estimates<br />
  47. 47. Akhilesh Bhargava<br />46<br />Case Fatality Rate<br />Total number of individuals <br />dying during a specified period<br />of time after disease onset<br />Case- <br />Fatality <br />Rate<br />=<br />X 100<br />Number of individuals with<br />the disease of interest<br />
  48. 48. Akhilesh Bhargava<br />47<br />Proportionate Mortality<br />Total number of deaths <br />from the Disease in given yr<br />Proportionate <br />Mortality <br />For a Disease<br />=<br />X 100<br />Total number of deaths in <br />the population during that <br />year<br />
  49. 49. Akhilesh Bhargava<br />48<br />Comparing Mortality in Different Populations<br />Crude<br />Age Adjustment<br />Direct<br />Indirect (Standardized Mortality Ratio)<br />Cohort Analysis<br />Life-table Analysis<br />Median survival<br />Life expectancy<br />
  50. 50. Akhilesh Bhargava<br />49<br />Trends in Mortality:Artifactual<br />
  51. 51. Akhilesh Bhargava<br />50<br />Measures of Mortality:<br />Mortality rate<br />Cause specific<br />Age specific<br />Case-fatality rate<br />Proportionate mortality rate<br />Standardized Mortality Rates<br />
  52. 52. Akhilesh Bhargava<br />51<br />Why study Mortality-<br />Eternal, ultimate experience<br />A measure of disease severity<br />Effectiveness of treatment<br />Surrogate for incidence (in severe, fatal diseases)<br />Comparison of rates in two or more population or one population at different times<br />
  53. 53. Akhilesh Bhargava<br />52<br />Mortality Data- Problems<br />Change in coding of ICD revisions<br />Changes in definitions of diseases<br />Underlying cause of death excludes Information on immediate Cause & those in between two.<br />Denominator may not be available<br />Numerator alone does not give rates and calls for standardization<br />
  54. 54. Akhilesh Bhargava<br />53<br />Comparison of Rates<br />

×