Mortality and Disease Impact Measures (BSc Medical Sciences) PDF

BSc Medical Sciences: Epidemiology Assistant Prof. Dr. Soza Th. Baban  Introduction and Review How often new cases In Week 3, we discussed: occur in a...

BSc Medical Sciences: Epidemiology Assistant Prof. Dr. Soza Th. Baban  Introduction and Review How often new cases In Week 3, we discussed: occur in a population Fifitsferm over a specific period eg/foodpoisoning , outbreak ↑ > probability of individual the 1. Measures of morbidity, including incidence rates, cumulative developingincidence, disease overtime a & attack rates, prevalence, and disease surveillance. Tracking > - and spread of the occurrence diseases to guide public health decision Y Total number of casesin pop- 2. Understand and calculate the case fatality rate (CFR) and explain its i proportion of individual diagnosed importance in assessing disease outbreaks. with disease who die from it a. 3. Interpret and analyse spot maps to identify disease patterns. ↳ This Mep show where people aregetting the disease Learning objectives By the end of this session, students should be able to: 1. Define key mortality measures including mortality rates, case-fatality, and proportionate mortality and understand their differences. 2. Calculate and interpret proportionate mortality. 3. Compare mortality rates across populations with different demographics. 4. Understand application of mortality rate in public health. Let’s go through each of these points in detail!  overall Crude Mortality (or Death) Rate The Crude Mortality Rate (CMR) is the simplest measure of mortality. It represents the total number of deaths in a population over a given period, regardless of the cause of death. This number & helps us see if ⑩ more Formula: (Number of deaths / Total population) * 1000 => - or fewer people are dying in but it doesn't tell grout a us It is important to recognize that the crude death rate summarizes the effect of two factors: age A. population composition gender B. age-specific death rates (which reflect the probability of dying) Likelihood of dying)  Crude Mortality (or Death) Rate Population Crude Mortality Rate per 1000 Popultation (A) White 9.95 Example: (B) Black 7.35 The above table shows the crude death rates of two populations, A and B by Race, State of Maryland, USA 2015: The crude death rate for population A is 9.95 per 1000. The crude death rate for population B is 7.35 per 1000. a Apparently, population B appears healthier, than population A. Death rates by age per 1000 population Race All ages 85 year year year year year year year year year year year A 9.95 4.06 0.21 0.11 0.64 1.29 1.73 3.62 7.68 16.45 45.39 138.7 B 7.35 11.25 0.43 0.78 1.14 1.74 2.23 5.09 11.14 21.55 49.49 124.45  it tells flow many people us died from Cause-Specific Mortality (or death) Rate ONE thing-like Cancer , accidents ? The Cause-Specific Mortality Rate (CSMR) focuses on the number of deaths due to a specific cause in a population. * it helps see which sickness are we us biggest problem so can help more people avoid them The specific death rates may be: (a) cause or disease specific - e.g., tuberculosis, cancer, accident; - (b) related to specific groups e.g., age-specific, gender-specific, age and gender specific, etc. CSMR can also be made specific for many other variables such as income, religion, race, housing, etc. Specific death rates can help us to identify particular groups or groups "at- risk", for preventive action. death in one thing No of deaths from specific cause ×1,000 Total population Example: If 100 people die from heart disease in a population of 100,000: (100 / 100,000) * 1000 = 1 per 1,000 people die from heart disease. Cause-Specific Mortality (or death) Rate > e O - & Becomefil ⑧ 3  it shows which cause Proportional mortality rate us of death is most common in a group Proportionate mortality rate shows the percentage of deaths in a population that are due to a specific cause, relative to all deaths. It is sometimes useful to know what proportion of total deaths are due to a particular cause (e.g., cancer) or what proportion of deaths are occurring in a particular age group (e.g., above the age of 50 years). Proportional mortality rate expresses the "number of deaths due to a particular cause (or in a specific age group) per 100 (or 1000) total deaths". (a) Proportional mortality from a specific disease Number of deaths from the specific disease in a year ×100 Total deaths from all causes in that year  Proportional mortality rate The proportionate mortality from cardiovascular disease in the United States in 2015 is defined as follows: In other words, of all deaths in the United States, what proportion was caused by cardiovascular disease? Proportional mortality from cardiovascular diseases in the US in 2015 (%) Number of deaths from cardiovascular disease in the US in 2015 ×100 Total deaths in the US in 2015 all kind of disease  Proportional mortality rate (b) Under-5 proportionate mortality rate Number of deaths under 5- - 5 years of age in the given year - ×100 Total number of deaths during the same period (c) Proportional mortality rate for aged 50 years and above Number of deaths of persons aged 50 years and above ×100 Total deaths of all age groups in that year any age  Proportional mortality rate This figure shows proportionate mortality from heart disease by age group. In each age group, the full bar represents all deaths (100%), and deaths from heart disease are indicated by the dark blue portion. We see that the proportion of deaths from heart disease increases with age. However, this does not tell us that the risk of death from Deaths from heart disease as a percentage of deaths from all causes, by age group, United States, 2014. heart disease is also increasing. This is demonstrated in the following examples.  Cause rate specific Mortality (SMR) · is about how from one many people died cause. compares deaths from ① it one cause to the total number of people in the population (NOT JUST THOSE WHO DIED) CSMRz deaths from one case x1000 - Total population (not the onewho died) Entire population Krells to us how dangerous a specific disease not just is everyone in the population , those who already died. &R is about what percentage of all deaths were caused by one thing. & it compares deaths from one specific cause to all deaths in the population. from one cause PMR2Deths X100 Total deaths (all cause) figures out the most common cause of death ina group  Case Fatality Rate (CFR) How deadly is a disease CFR measures the severity of a disease by calculating the percentage of people who die from it. What percentage of people who have a certain disease die within a certain time after their disease was diagnosed? it helps understand It is useful for understanding how deadly an outbreak is. how dangerous is disease ⑪ us a Formula: CFR =(Number of Deaths /Number of Confirmed Cases x100 Example: If there are 10 deaths out of 200 confirmed cases of a disease, the CFR is: O CFR = (10/200) x 100 = 5%. Number of individuals dying during a specified - period of time after disease onset or diagnosis CFR Only looks at people ×100 who got the disease it's like if you get the disease, what are the chances you don't No. of individuals with the specified disease Surive ? it means how deadly Comparison of Mortality rate About whole population is a disease > - people who already people from city Show with Case-Fatality in the same year among may died have it from the ? ] ↳ specific to sick people (How many flu patient die ?] Assume a population of 100,000 people of whom 20 are sick with disease X, and in 1 year, 18 of the 20 die from disease X How death from this disease in whole pop is ? common Assume that in a population 18 Death fromdisease = of 100,000 persons, 20 have = 0.00018, or 0.018% disease X. > - Mortality rate from - - disease X= 100,000 Total pop- & In 1 year, 18 people die from that disease. focusesonentire population (Healthysick) The mortality is very low if I catch this disease, whatare the chances I might die ? (0.018%) because the disease is rare; however, 18 Death from disease & Case-fatality rate from = 0.19, or 90% once a person has the disease, the chances of his disease X= 20 confined case focus only peor her dying are great (90%).  & looks at entire population (healthy +sick) CFR only looks at sick people summary of my writings Mortality Pate > - Big Picture (Looks at everyone CfR Smaller picture (looks at those who = only got the disease) Example fever spread MR (Mortality Rate) Case Fatality Rate (CFR) S 3 3 - Population (100 000 people) , MEzo x10000 CFR2 x100250 % Only 100 people catch disease 8 : 5 deaths per 1000 high betifyouCatchthedisassee 50 people died how bee it's RARE you Homework: 1) What is the difference between case-fatality and a mortality rate? (provided with example) 2) What is the difference between mortality rate and proportionate mortality? (provided with example) 3) What is the importance of measuring mortality rate? Why look at mortality? Explain with an example Refer to Gordis Epidemiology book, page 68 to 75.  Measures how many people with disease Survival rate a arestill alive after a period 15 yeas) It is the proportion of survivors in a group, (e.g., of patients) studied and followed over a period (e.g., a 5-year period). It is a method of describing prognosis in certain disease conditions. Survival experience can be used as a yardstick for the assessment of standards of therapy. The survival period is usually reckoned from the date of diagnosis or start of the treatment. Survival rates have received special attention in cancer studies. Total number of patients Survival rate = alive after 5 years ×100 uped Cancer 80 still alive after5 year Total number of patients diagnosed or treated Ye80% SRz  Challenges in Mortality Measurement Mortality data is crucial for public health, but there are challenges in ensuring accurate measurement: 1. Underreporting: Some deaths may go unrecorded, especially in under- resourced areas. 2. Misclassification: Errors in identifying the correct cause of death can skew mortality statistics. Standards 3. Inconsistent data: Different countries and regions might use different criteria for measuring mortality. 4. Population differences: Differences in age, sex, or location can make mortality rates difficult to compare.  Application of Mortality Measures Mortality measures are essential tools in public health for understanding how diseases impact different populations. These measures help public health officials: example/CV disense Prioritize interventions by identifying diseases that contribute most to mortality. Meth programs Allocate resources effectively by understanding disease burden. Evaluate the success of public health interventions by monitoring trends in mortality. vaccine S Health programs InformS health policy decisions based on accurate mortality data. Using Mortality data to guide health policies  Recap and Q&A Today, we covered essential mortality measures: Measures overall death population in Crude Mortality Rate Cause-Specific Mortality Rate identifies which diseases most del population are in Case Fatality Rate percentage of people who die from disease after getting it > -. Proportionate Mortality > shows which cause contributes most to - deaths We also discussed challenges in mortality measurement and how these measures are applied in public health. Feel free to ask any questions or share your thoughts! ⑭ ⑭ Deadly Q of TD fro 1 case Alive & Preparation for Next Session For next session, please: 1. Read Chapter 5 (Pages 94-105) from 'Gordis Epidemiology'. 2. Be prepared to discuss how these measures are used to evaluate population health outcomes.