Common Health Indices in the Community PDF

EPIDEMIOLOGY | TRANS 2 LE Common Health Indices in the Community DR. CATHERINE DANIELLE R. DUQUE-LEE |...

EPIDEMIOLOGY | TRANS 2 LE Common Health Indices in the Community DR. CATHERINE DANIELLE R. DUQUE-LEE | (01/23/2024) | Version 3 01 11 OUTLINE → E.g. Sexually transmitted disease in commercial sex workers ▪ they may not have the disease but they are at higher risk of I. Rate, Ratio, and Proportion IV. Common Statistical Indices contracting STD due to nature of their work A. Rate in Population Studies B. Ratio A. Estimates of Population COMPARING RATES II. Health Indices Size Numerators for all groups being compared must be defined or A. Morbidity Rates B. Estimates of Age-Sex diagnosed in the same way B. Fertility Rates Distribution → E.g. Gamers may mean those involved in online gaming, or C. Mortality Rates C. Swaroop Uemura Index those in the casino D. Important Indices for D. Quality-Adjusted Life → You have to be specific with how you define your numerator. Health Administrators Years (QALYs) Constant multipliers being used must be the same E. Over-all Index of a Health E. Disability-Adjusted Life → Multipliers or nth power should be constant for all compared Status of a Population Years (DALYs) rates. III.Rates for Public V. Exercise 1: Rates and Ratio → E.g. x 100,000 population for all rates Assessment A. Part I Time intervals must be the same A. Crude Rates B. Part II → All time units must be the same, if the time component is an B. Specific Rates C. Part III hour then you may only compare it to rate with hours as units D. Part IV ▪ Or you may do conversion VI. Review Questions The 3 comparisons for rates VII. References → Target rate (ex. the real target to the goal) Must Lecturer Book Previous Youtube → Two different populations (ex. Visayas to Luzon population) Know Trans Video → Same population, different times B. RATIO Simplest of all statistical measures and there are no conditions on SUMMARY OF ABBREVIATIONS their use (one number divided by another number) IR Incidence Rate Expressions of a relationship between two quantities which can be PR Prevalence Rate related or totally independent of each other. CBR Crude Birth Rate → E.g. The ratio of boys to girls in first year is 1:3 CDR Crude Death Rate → Can also be independent of each other GFR General Fertility Rate ▪ E.g. The ratio of tables to first year students is 1:10 SDR Specific Death Rate PROPORTION IMR Infant Mortality Rate A special type of ratio: What is in the numerator is also counted in MMR Maternal Mortality Rate the denominator NMR Neonatal Mortality Rate → E.g. The proportion of girls in class who are single AASDR Annual age-specific death rate → Numerator: Single girls in class; over total number of girls in LEARNING OBJECTIVES class ✔ To define rate, ratio, and proportion ▪ Number of singles are still accounted for in the ✔ To explain the concepts of prevalence and incidence denominator ✔ To discuss the analysis of rates Expressed as a percentage (%) ✔ To discuss the common statistical data indices used in Reflects events in selected portions of a population population studies → We want to know the proportion of the selected characteristics you wish to assess in a given population I. RATE, RATIO, AND PROPORTION A. RATE II. HEALTH INDICES Frequency of events that occur in a defined time period divided by Measurements that are used as indicators to reflect the health the average number of people at risk during the period being status of a population studied Incidence or Prevalence of disease Estimate of risk Frequencies of morbidity or mortality → there is always a component of time (hour, period, or year) 3 categories under health indices: → Morbidity Rates 𝑛𝑜. 𝑜𝑓 𝑐𝑎𝑠𝑒𝑠 𝑜𝑐𝑐𝑢𝑟𝑟𝑖𝑛𝑔 𝑑𝑢𝑟𝑖𝑛𝑔 𝑔𝑖𝑣𝑒𝑛 𝑡𝑖𝑚𝑒 𝑝𝑒𝑟𝑖𝑜𝑑 𝑛 𝑅𝑎𝑡𝑒 = 𝑥 10 → Fertility Rates 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑎𝑡 𝑟𝑖𝑠𝑘 𝑑𝑢𝑟𝑖𝑛𝑔 𝑡ℎ𝑒 𝑠𝑎𝑚𝑒 𝑝𝑒𝑟𝑖𝑜𝑑 → Mortality Rates ▪ The value of 10 to the n power is usually 1 or 100 for A. MORBIDITY RATES common attributes Measure frequency of illness within specific population ▪ For rare attributes and for most diseases the value may be → Incidence Rate 1,000, 100,000, or 1 million → Prevalence Rate CRITERIA FOR THE VALID USE OF RATES ▪ Point Prevalence Rate All events counted in the numerator must have happened to → Attack Rate persons in the denominator INCIDENCE RATE (IR) → E.g. Dyspnea (Difficulty in breathing) is one of the chronic Measures how fast an infection or disease condition occurs symptoms of asthmatic individuals Considers only new cases seen during a specific time period → Numerator: Dyspnea Usually used to measure acute events like outbreaks or → Denominator: Asthmatic individuals epidemics, or for monitoring the occurrence of certain events → The rate of difficulty of breathing in asthmatic individuals → E.g. The development of NCDs in a population All of the persons counted in the denominator must have been at risk for the events in the numerator LE 1 Common Health Indices to the Community | Enrique, TE | Esposo, Estrella, S., AVPAA | J. Nalugon PAGE 1 of 8 TRANS 2 Escolano, Escobar, Escueta, Esguerra*, Esteban, Estacio, Espino, Eugenio, J Estrella, F., Eugenio, C., Eusebio., Evangelista, K., Evangelista, S., Fababeir EPI | LE 2 Common Health Indices to the Community | Dr. Catherine Danielle R. Duque-Lee 𝐼𝑅 = 𝑛𝑜. 𝑜𝑓 𝑝𝑒𝑜𝑝𝑙𝑒 𝑤ℎ𝑜 𝑑𝑒𝑣𝑒𝑙𝑜𝑝 𝑑𝑖𝑠𝑒𝑎𝑠𝑒 𝑑𝑢𝑟𝑖𝑛𝑔 𝑎 𝑝𝑎𝑟𝑡𝑖𝑐𝑢𝑙𝑎𝑟 𝑡𝑖𝑚𝑒 ×𝐹 “Crude” because only live-births are counted and the denominator 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 (𝑚𝑖𝑑𝑦𝑒𝑎𝑟 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛) 𝑜𝑓 𝑝𝑒𝑜𝑝𝑙𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 is the total population which includes children, old people, and ▪ F = factor which is a unit that may be 100, 1,000, 10,000, or males 100,000 (multiple of 10) depending on what is convenient → Midyear population is used because it is a good ▪ Denominator used sometimes changes depending on what approximation of the average of the population at the start of will make the answer a whole number signifying a number of the year and population at the end of the year persons or individuals. 𝑡𝑜𝑡𝑎𝑙 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 𝑖𝑛 𝑎 𝑦𝑒𝑎𝑟 𝐶𝐵𝑅 = 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 (𝑚𝑖𝑑𝑦𝑒𝑎𝑟 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛) × 1000 PREVALENCE RATE (PR) Proportion of the population that has the disease at a specific GENERAL FERTILITY RATE (GFR) point in time Reproductive capacity of the country Includes those who already have the disease at the start of the Reproductive age of women: 15-44 years old start of the study period and new cases seen during the same 𝑡𝑜𝑡𝑎𝑙 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 𝑖𝑛 𝑎 𝑦𝑒𝑎𝑟 study period (old and new cases) 𝐺𝐹𝑅 = 𝑚𝑖𝑑𝑦𝑒𝑎𝑟 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑤𝑜𝑚𝑒𝑛 15−44 𝑦𝑒𝑎𝑟𝑠 𝑜𝑙𝑑 × 1000 Good measure to use for chronic illnesses (e.g., TB, hypertension, diabetes mellitus, or long-standing illnesses TOTAL BIRTH RATE 𝑡𝑜𝑡𝑎𝑙 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 + 𝑓𝑒𝑡𝑎𝑙 𝑑𝑒𝑎𝑡ℎ𝑠 Determined through survey 𝑇𝑜𝑡𝑎𝑙 𝐵𝑖𝑟𝑡ℎ 𝑅𝑎𝑡𝑒 = 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 (𝑚𝑖𝑑𝑦𝑒𝑎𝑟 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛) × 1000 𝑃𝑅 = 𝑛𝑜. 𝑜𝑓 𝑝𝑒𝑜𝑝𝑙𝑒 𝑤𝑖𝑡ℎ 𝑡ℎ𝑒 𝑑𝑖𝑠𝑒𝑎𝑠𝑒 (𝑜𝑙𝑑 𝑎𝑛𝑑 𝑛𝑒𝑤) 𝑎𝑡 𝑎 𝑔𝑖𝑣𝑒𝑛 𝑝𝑜𝑖𝑛𝑡 𝑖𝑛 𝑡𝑖𝑚𝑒 ×𝐹 C. MORTALITY RATES 𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑒𝑜𝑝𝑙𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 Crude Death Rate (CDR) POINT PREVALENCE Specific Death Rates (SDR) A measure of the proportion of the population with the disease at a → Age-specific Death Rate single point in time (ex. a particular/specific date) → Sex-specific Death Rate → Case-fatality Rate 𝑡𝑜𝑡𝑎𝑙 𝑐𝑎𝑠𝑒𝑠 (𝑜𝑙𝑑 𝑎𝑛𝑑 𝑛𝑒𝑤) 𝑎𝑡 𝑎 𝑓𝑖𝑥𝑒𝑑 𝑝𝑜𝑖𝑛𝑡 𝑖𝑛 𝑡𝑖𝑚𝑒 𝑃𝑜𝑖𝑛𝑡 𝑃𝑟𝑒𝑣𝑎𝑙𝑒𝑛𝑐𝑒 = 𝑡𝑜𝑡𝑎𝑙 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑎𝑡 𝑡ℎ𝑎𝑡 𝑡𝑖𝑚𝑒 × 100 Cause-Specific Death Rate (mortality rate by cause) Proportionate Mortality Rates PERIOD PREVALENCE Infant Mortality Rate (IMR) The proportion of the population with the disease at any time Neonatal Mortality Rate (NMR) during a specified period or interval of time (ex. time frame) Fetal Death Ratio Fetal Death Rate 𝑡𝑜𝑡𝑎𝑙 𝑐𝑎𝑠𝑒𝑠 (𝑜𝑙𝑑 𝑎𝑛𝑑 𝑛𝑒𝑤) 𝑎𝑡 𝑎 𝑓𝑖𝑥𝑒𝑑 𝑝𝑒𝑟𝑖𝑜𝑑 𝑖𝑛 𝑡𝑖𝑚𝑒 𝑃𝑒𝑟𝑖𝑜𝑑 𝑃𝑟𝑒𝑣𝑎𝑙𝑒𝑛𝑐𝑒 = 𝑡𝑜𝑡𝑎𝑙 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑎𝑡 𝑡ℎ𝑎𝑡 𝑡𝑖𝑚𝑒 × 100 Perinatal Mortality Rate CRUDE DEATH RATE (CDR) FACTORS INFLUENCING OBSERVED PREVALENCE RATE Risk of dying of a population from all causes for a given time or Prevalence rate year → Increased by anything that will increase the numerator or Death rate from a particular cause (cause-specific) decrease the denominator → Decreased by anything that will decrease the numerator or 𝐶𝑟𝑢𝑑𝑒 𝐷𝑒𝑎𝑡ℎ 𝑅𝑎𝑡𝑒 = 𝑡𝑜𝑡𝑎𝑙 𝑑𝑒𝑎𝑡ℎ𝑠 𝑓𝑟𝑜𝑚 𝑎𝑙𝑙 𝑐𝑎𝑢𝑠𝑒𝑠 𝑖𝑛 𝑎 𝑦𝑒𝑎𝑟 × 1000 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 (𝑚𝑖𝑑𝑦𝑒𝑎𝑟 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛) increase the denominator will decrease the prevalence rate MATERNAL MORTALITY RATE (MMR) Table 1. Factors influencing observed prevalence rate Ideal denominator: number of pregnant women INCREASES PR DECREASES PR → Dynamic data that is difficult to retrieve as it changes in months Longer duration of the Shorter duration of the time and pregnancy may be detected late disease disease “Maternal mortality ratio” → Increase the old cases → Decrease in old cases → Sometimes called this since the denominator does not include other outcomes of pregnancy such as stillbirths Prolongation of life of High case-fatality rate from Measures: patients without cure the disease → Risk of dying due to pregnancy, childbirth, and puerperium → Increase old cases → Decrease in old cases ▪ Puerperium: period of 6 weeks after giving birth Increase in new cases (deaths) → Quality of medical services (increase in incidence) Decrease in new cases ▪ Adequacy and accessibility of health facilities In-migration of cases (decrease in incidence) ▪ Maternal prenatal behavior → Increase in old and new In-migration of healthy Indicator of progress of a nation in providing adequate nutrition cases people and medical care for pregnant women Out-migration of healthy → Increase in PR people denominator 𝑀𝑀𝑅 = 𝑑𝑒𝑎𝑡ℎ𝑠 𝑎𝑚𝑜𝑛𝑔 𝑤𝑜𝑚𝑒𝑛 𝑑𝑢𝑒 𝑡𝑜 𝑚𝑎𝑡𝑒𝑟𝑛𝑎𝑙 𝑐𝑎𝑢𝑠𝑒𝑠 × 1000 𝑡𝑜𝑡𝑎𝑙 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 𝑓𝑜𝑟 𝑡ℎ𝑒 𝑦𝑒𝑎𝑟 → Decrease of PR Out-migration of cases denominator → Decrease old and new INFANT MORTALITY RATE (IMR) In-migration of susceptible cases State of health of infants people Improved cure rate of Measures the risk of dying before 1 year of age → Increase in new cases cases → NOTE: not all infants who die in a year were born on the same because usually they → Decrease old cases year are the first ones to May also be used to measure the adequacy of health services have the disease available Improved diagnostic High IMR may be due to: facilities (better reporting) → High incidence of communicable disease → Increase in new cases → Poor state of sanitation detected → Inadequate health facilities Can be artificially decreased by increasing denominator by better B. FERTILITY RATES reporting of live births Indices of Fertility → Crude Birth Rate (CBR) 𝐼𝑀𝑅 = 𝑡𝑜𝑡𝑎𝑙 𝑖𝑛𝑓𝑎𝑛𝑡 𝑑𝑒𝑎𝑡ℎ𝑠 𝑖𝑛 𝑎 𝑦𝑒𝑎𝑟 × 1000 𝑡𝑜𝑡𝑎𝑙 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 𝑑𝑢𝑟𝑖𝑛𝑔 𝑡ℎ𝑒 𝑦𝑒𝑎𝑟 → General Fertility Rate (GFR) → Total Birth Rate (TBR) NEONATAL MORTALITY RATE (NMR) CRUDE BIRTH RATE (CBR) the risk of dying in the first four weeks of life → or the first 28 days of life Measures the total live births in a given population EPI Common Health Indices to the Community PAGE 2 of 8 EPI | LE 2 Common Health Indices to the Community | Dr. Catherine Danielle R. Duque-Lee B. SPECIFIC RATES 𝑁𝑒𝑜𝑛𝑎𝑡𝑎𝑙 𝐷𝑒𝑎𝑡ℎ𝑠 𝑁𝑀𝑅 = × 1000 When a population is divided into homogenous subgroups based 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 on a particular characteristic (e.g., age, sex, risk factors, etc.) PERINATAL MORTALITY RATE → Denominator is usually specific to a target population Measures the risk of dying during the period of birth (Fetal Death + → Ex. Case Fatality Rate EARLY Neonatal Death) Meant to give a more meaningful picture of the health status of a population 𝑛𝑜. 𝑜𝑓 𝑠𝑡𝑖𝑙𝑙𝑏𝑖𝑟𝑡ℎ + 𝑛𝑜. 𝑜𝑓 𝑑𝑒𝑎𝑡ℎ𝑠 𝑖𝑛𝑓𝑎𝑛𝑡𝑠 𝑢𝑛𝑑𝑒𝑟 7 𝑑𝑎𝑦𝑠 𝑜𝑓 𝑎𝑔𝑒 𝑃𝑀𝑅 = 𝑛𝑜. 𝑜𝑓 𝑠𝑡𝑖𝑙𝑙𝑏𝑖𝑟𝑡ℎ𝑠 + 𝑛𝑜. 𝑜𝑓 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 × 1000 STANDARDIZED RATES FETAL DEATH RATE (FDRate) Also called adjusted rates Crude rates that have been modified to control for the effects of The state of health of unborn children certain characteristics in the population 𝑛𝑜. 𝑜𝑓 𝑑𝑒𝑎𝑡ℎ𝑠 𝑑𝑢𝑟𝑖𝑛𝑔 𝑡ℎ𝑒 𝑦𝑒𝑎𝑟 Allows for valid comparisons of rates 𝐹𝐷𝑅𝑎𝑡𝑒 = 𝑛𝑜. 𝑜𝑓 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 𝑎𝑛𝑑 𝑓𝑒𝑡𝑎𝑙 𝑑𝑒𝑎𝑡ℎ𝑠 𝑑𝑢𝑟𝑖𝑛𝑔 𝑠𝑎𝑚𝑒 𝑦𝑒𝑎𝑟 × 1000 A fair comparison can be made between two populations as long as the comparisons are made using indices, measurements, or FETAL DEATH RATIO (FDRatio) values adjusted using standardization Measures the risk of dying before birth Fetal death ratio together with Neonatal Mortality Rate, Perinatal DIRECT STANDARDIZATION Mortality rate have live births as denominator Removes the biasing effect of the different age structures of 𝑛𝑜. 𝑜𝑓 𝑑𝑒𝑎𝑡ℎ𝑠 𝑑𝑢𝑟𝑖𝑛𝑔 𝑡ℎ𝑒 𝑦𝑒𝑎𝑟 𝐹𝐷𝑅𝑎𝑡𝑖𝑜 = 𝑛𝑜. 𝑜𝑓 𝑙𝑖𝑣𝑒 𝑏𝑖𝑟𝑡ℎ𝑠 𝑑𝑢𝑟𝑖𝑛𝑔 𝑠𝑎𝑚𝑒 𝑦𝑒𝑎𝑟 × 1000 different populations Calculates the overall incidence or mortality rate of a “standard” CAUSE-SPECIFIC DEATH RATES population if it had the same rates as the study population Measures risk of dying due to a particular cause TO USE DIRECT STANDARDIZATION, MUST HAVE: Example: ▪ Age-specific disease rates in the study population 𝑛𝑜. 𝑜𝑓 𝑑𝑒𝑎𝑡ℎ𝑠 𝑓𝑟𝑜𝑚 𝑇𝐵 𝑖𝑛 2010 × 1000 ▪ Age distribution of the standard population 𝑀𝑖𝑑𝑦𝑒𝑎𝑟 𝑃𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 2010 − The standard population may be any population. Though PROPORTIONATE MORTALITY RATE is usually often a larger population of which the Measures the magnitude of death from a particular cause populations to be compared are a part of Magnitude - how much the disease contributed to the total deaths of the population INDIRECT STANDARDIZATION Used if the population to be standardized is small 𝑛𝑜. 𝑜𝑓 𝑑𝑒𝑎𝑡ℎ𝑠 𝑓𝑟𝑜𝑚 𝑇𝐵 𝑖𝑛 2010 × 100 Calculates the number of cases that would have been expected 𝑇𝑜𝑡𝑎𝑙 𝑛𝑜. 𝑜𝑓 𝑑𝑒𝑎𝑡ℎ𝑠 𝑖𝑛 2010 to see in the study population *the PMRs of every condition that contributed to the total death in In computing, borrow the rate of the group with the higher a population will in fact constitute a pie chart of the total deaths population size for that population Standardized Mortality Rate (SMR) 𝑂𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝐶𝑟𝑢𝑑𝑒 𝐷𝑒𝑎𝑡ℎ 𝑅𝑎𝑡𝑒 CASE-FATALITY RATE → 𝑆𝑀𝑅 = 𝐸𝑥𝑝𝑒𝑐𝑡𝑒𝑑 𝐶𝑟𝑢𝑑𝑒 𝐷𝑒𝑎𝑡ℎ 𝑅𝑎𝑡𝑒 × 100 Measures the killing power of a disease → If >100: force of mortality is higher in the study population than Lethality rate, killing rate in the standard population → If