بِسْمِ الله الرحمّن الرَحيم الذي خلقَ الموتَ والحياةَ لِيبلوكُم أيكُم أحسَنُ عملاً وهو العزيزُ الغفورُ الملك{2} صدقَ الله العظيم
Measures of Mortality Dr. Yousif AbdulRaheem FICMS/CM Department of Community Medicine Al Kindy College of Medicine Baghdad University E-mail yousifkindi@yahoo.com
Learning Objectives To understand the concepts of mortality measures , that are commonly used in vital statistics To understand the way of their calculation.
2,797,461 13,544,229
Mortality is clearly an index of the severity of the problem from both clinical and public health standpoints.
Most of our information about deaths comes from “Death Certificate” is a document that declares the date, location and cause of a person's death. This document is issued by a government official physician to record and send to vital statistics register office
Deaths are coded according to the underlying causes. Analysis of mortality information depends on the quality of the data included. Deaths are coded according to the underlying causes. The disease or injury which initiate the train of morbid events leading directly or indirectly to death
Immediate cause (final disease or condition resulting in death) Enter the disease, or complications that cause death. Do not enter the mode of dying, such as cardiac or respiratory arrest, shock, or heart failure. a. Rapture of myocardium Approximate interval between onset and death Mins- Hrs Sequentially, list conditions, if any leading to immediate cause b. Acute myocardial infarction c. Chronic ischemic heart disease Days Years Other significant conditions contribute to death Diabetes , smoking Did tobacco use contribute to cause of death yes no uncertain
Causes of Death : As written in the death notification, there are three spaces for the cause of death: The immediate cause, Intermediate conditions, and Underlying cause, which is the official cause of death
(No –Age-Sex-race-Occupation) Immediate Intermediate Contributor Myocardial Coronary Diabetes Infarction Ht. Disease Epidural Motor vehicle Alcohol Haemorage Accident Intoxication Pneumocystitis AIDS IV drug Pneumonia abuse Imp. of Death certificate to Epidemiologist. (No –Age-Sex-race-Occupation)
ICD, now in its 10th revision The official cause of death classified according to the International Statistical Classification of Diseases, Injuries, and Causes of Death (ICD) Revised every 10 years by the WHO. ICD, now in its 10th revision
Important when we compare the cause of death in two periods Coding categories and regulation of disease change from one revision to another Important when we compare the cause of death in two periods Nosologist is a person with experience in coding the causes of death according to the ICD.
Leading Causes of Death, 1900 and 2000, USA Pneumonia / influenza Heart disease 2 TB Neoplasms 3 Diarrhea Cerbrovascular 4 Heart disease* COPD 5 Cerebrovascular* Pneumonia/ influenza
Entering diagnosis on a death certificate: exercise A person who has a feverish illness diagnosed on laboratory tests as influenza, develops cough and shortness of breath shown to be pneumonia, followed by a deep venous thrombosis. The doctors suspect that pulmonary embolus has occurred but before it can be confirmed by tests, the patient collapses and dies unexpectedly. Assume that there is no post-mortem because the relatives refuse permission Immediate Intermediate contributor Pulmonary embolism DVT pneumonia Influenza,
Uncertainty in Reported Cause of Death Michael Alderson (1988) identified four areas where uncertainties or inaccuracies can arise in reporting causes of death: incorrect diagnosis (last attending physician and/or autopsy) incorrect completion of death certificate inaccurate processing and publication of the mortality statistics invalid classification of diseases/injuries
Distinguishing Natural from Other Causes of Death Multiple Cause-of-Death Analysis Use of Medical Examiner and Coroner Records to supplement Death Certificate Data Need to rule out homicide, suicide or “accident” , i.e., unintentional injury, before a death can be validly attributed to natural causes. Homicide or SIDS?
1- Annual crude mortality rate: All deaths during calendar year Total mid year population = Usually expressed per 1000 population Total population is used even though the risk of death is different for different age groups Universally used as generalized indicator of a population’s health. Often referred to as the mid-point population
May not be truly reflective without accounting for age, race, or sex. Usually K= 1,000 Numerator is usually from death certificates Denominator is usually from census The crude death rate is the starting point for further development of adjusted rates. May not be truly reflective without accounting for age, race, or sex.
Ex: In a population of 2 million, the total reported deaths from all causes were 12000 in 2005. The annual crude mortality rate in that year per 1000 persons was: 12000/2000000 X 1000 = 6 per 1000 population per year.
2- Proportionate mortality ratio: Total number of deaths due to a certain disease Total number of deaths from all causes. Ex: There were 6000 deaths (1200 leukemia, 1750 stroke, 250 pneumonia, 250 Hodgkin's disease, 2500 acute myocardial infarction, and 50 others) in certain community which had a population of 2.5 million populations in 1996. The Proportionate mortality rate for leukemia is 1200 /6000 X 100 = 20% = X 100
Defined as the number of deaths assigned to a specific cause in a calendar year, divided by the total number of deaths in that year, the quotient multiplied by 100 Example: Country Y: Total deaths from all causes: 1,500,000; deaths from cancer: 675,000 Proportional mortality ratio = 675,000/1,500,000 x 100 = 45% of total deaths per year from cancer
not a measure of the risk of dying of a particular cause. Indicates relative importance of a specific cause of death; not a measure of the risk of dying of a particular cause. PMR (%) for HIV among the 25- to 44-year-old group = 15%. That mean form each 100 deaths in that age group, 15 deaths due to HIV
3- Age (sex, race…..) specific mortality rate: Number of people who died in a particular age (sex, race..) Total mid year population of the same age (sex, race….) during the same year. Ex: Mortality from MI in community X regarding age group was as follow: Age group (years) No. of population No. of deaths from MI 45-55 250'000 1000 56-65 150'000 750 ≥66 50'000 50 TOTAL 450'000 1800 Age specific mortality rate (45-55): 1000/250000X 1000= 4 per 1000. Age specific mortality rate (56-65): 750/150000X1000= 5 per 1000. Age specific mortality rate (≥66) : 50/50000X1000=1 per 1000 =
4- Cause specific mortality rate: Number of deaths due a specific disease Total mid year population Ex: There were 6000 deaths (1200 leukemia, 1750 stroke, 250 pneumonia, 250 Hodgkin's disease, 2500 acute myocardial infarction, and 50 others) in certain community which had a population of 2.5 million populations in 1996. The cause specific mortality rate for acute MI in this population was: 2500/2500'000X1000=1 per 1000 =
= 80 accidental deaths per 100,000 population per year Example: Country Y: Population: 5,000,000; deaths due to accidents are 4,000 Cause-specific death rate= 4,000/5,000,000 x 100,000 = 80 accidental deaths per 100,000 population per year
The 10 Leading Causes of Death, 25-44 Years, All Races, Both Sexes, U The 10 Leading Causes of Death, 25-44 Years, All Races, Both Sexes, U.S., 1996
5- Case fatality rate: Number of deaths due to specific disease Number of people with the same disease. (Usually express in percentage) Ex: In a city, there were 500 HIV- positive people of whom 5 died within a year after their initial diagnosis. The case fatality rate is 5/500 X100= 1%. Note: The ''survival rate'' in that year was 99%(100%-1%) =
Case-Fatality Proportion Number of deaths assigned to a given cause in a certain period, divided by number of cases of the disease reported during the same period, the quotient multiplied by 100. Example: In Country X: Number of male AIDS cases: 45,000; deaths from the disease: 37,000. Case-fatality proportion: 37,000/45,000 x 100 = 82.2% mortality among reported cases of AIDS
Comparison of a mortality rate and case fatality rate: Assume a population of 100'000 people of whom 20 are sick with disease ''X'', and in 1 year, 18 die from that disease. The mortality rate in that year from disease x = 18/100000 X 100 = 0.018%. The case fatality rate from disease x = 18/20 X 100 = 90%.
What factors affect mortality? Infant mortality – areas with high rates of infant mortality have high rates of overall mortality Malnutrition and under-nutrition Limited access to clean drinking water Poor sanitation and hygiene Diseases e.g: Malaria, AIDS Limited access to medical provision e.g. vaccination programmes Lifestyle Accidents Conflict (war, security, safety)
This list shows the 10 leading causes of death in 2002 (WHO) 12.6% Ischaemic heart disease 9.7% Cerebrovascular disease 6.8% Lower respiratory infections 4.9% HIV/AIDS 4.8% COPD 3.2% Diarrhoeal diseases 2.7% Tuberculosis 2.2% Malaria 2.2% Trachea/bronchus/lung cancers 2.1% Road traffic accidents
Years of potential life lost (YPLL). In recent years, another mortality index has been increasingly used. YPLL recognizes that death occurring in the same person at a younger age clearly involves a greater loss of future productive years than were it to occur at an older age.
Years Of Potential Life Lost (YPLL) The number of deaths due to a cause of disease multiplied by the difference in years between age at death and a certain target age. Target age can be 65, 70, mean age at death in the population, or any other age you choose. It is based on projected life expectancy
Years Of Potential Life Lost (YPLL) For example: If the target age is 70, then: 100 deaths at age 60 = 1,000 YPLL 50 deaths at age 50 = 1,000 YPLL 20 deaths at age 20 = 1,000 YPLL
5 year-SURVIVAL RATES Five-year survival rate = Number of people alive after five years Number alive at beginning of the interval Commonly used in chronic diseases such as cancer, where mortality may be spread out over several years. Usually disease-specific. Any interval can be used, 10 years also fairly common.
Some Special Mortality Rates
Neonate mortality rate = Infant mortality rate = Number of infant (< 1 year) deaths in one year Number of live births in that year Neonate mortality rate = Number of neonate (≤ 28 days) deaths Number of live births Stillbirth rate = Number of intrauterine deaths after 28 {22} weeks Total births
Perinatal mortality rate = Number of stillbirths + deaths in 1st week of life Total births Maternal mortality rate** = Number of deaths among women due to Pregnancy (usually per 100,000) Delivery and/or Puerperium in one year Number of live births in that year
In community A, the mortality rate due to TB is 1 per 100 000, while in community B, the mortality rate is 2 per 100 000. The inference is that TB is 2 times more in community B than it is in A. True or false Incorrect : because failure to distinguish between prevalence and mortality
Thank You Assistant Professor Yousif AbdulRaheem