Download Population Dynamics - Health - Lecture Slides and more Slides Public Health in PDF only on Docsity! POPULATION DYNAMICS AND HEALTH docsity.com DEMOGRAPHY Scientific study of population Births (Fertility) Sickness (Morbidity) Deaths (Mortality) Population movements (Migration) Other e.g. abortion rates, divorce rates etc. Scholars often focus on subtopics e.g. teenage fertility, immigrant fertility, Malay fertility, infant mortality, maternal mortality docsity.com AGE-SEX COMPOSITION OF A POPULATION Depicted by the Population Pyramid “Young” population: pyramid is triangular “Ageing” population: pyramid becomes more and more rectangular docsity.com “YOUNG” POPULATION % of total population under age 15 is high Median age as low as 15 or 16 Due to high fertility docsity.com “AGEING” POPULATION Elderly rises from 5% to more than 20% of total population Due mainly to low fertility e.g. Japan, Singapore “Young-old” versus “old-old” More and more elderly women More chronic & degenerative diseases Multiple health problems are common in elderly people docsity.com (1) FERTILITY Fertility rates differ by social variables: Differ by religious group e.g. Catholic Church and contraception Differ by social class – lower classes tend to have higher fertility Differ by region – people in rural areas tend to have higher fertility Differ by country – people in poor countries tend to have higher fertility docsity.com (1) FERTILITY Fertility rates can be affected by: Public policy e.g. some governments pressure couples to have fewer kids, other governments encourage them to have more! Culture e.g. religion and contraception Economics e.g. expense of having kids in industrial versus agricultural societies Technology e.g. are effective contraceptive methods available? docsity.com FERTILITY AND HEALTH High fertility can increase maternal and child mortality Continuous child-bearing can have a negative impact on maternal health Closely-spaced births (<18 months apart) & low birth weight babies (<2,500g) at higher risk Illegal abortions and maternal mortality “Female genital mutilation” & maternal mortality Sex-selective abortion in China and India docsity.com (2) MORBIDITY AND MORTALITY The Epidemiological Transition This refers to the change in disease patterns from mostly infectious diseases to mostly chronic and degenerative diseases Cancer, heart disease, stroke, injuries, diabetes, arthritis etc versus HIV/AIDS, SARS etc docsity.com MEASURES OF MORTALITY Infant mortality rate (deaths of babies under 1 year old) Neonatal mortality rate (<28 days after birth) Postneonatal mortality rate (between 28 days and 1 year old) IMR = Deaths of babies under 1 year X 1,000 Total live births docsity.com MEASURES OF MORTALITY IMR = Neonatal Mortality Rate + Postneonatal Mortality Rate Low Birth Weight (<2.5 kg at birth) greatly increases the risk of infant mortality docsity.com INCIDENCE RATE No. of NEW cases in fixed time period X 1,000 Population at risk docsity.com PREVALENCE RATE No. of people with a disease X 1,000 Population at risk docsity.com (3) MIGRATION Involuntary: slavery, ethnic persecution, wars, natural disasters, famines Voluntary: to seek jobs (skilled or unskilled), to get an education, because of marriage, upon retirement ------------------------------ Internal migration: within a country e.g. rural to urban International migration: skilled professionals to other countries docsity.com
