DEMOGRAPHY (2).ppt
- 1. DEMOGRAPHY OBJECTIVES • Define Demography • Know the characteristics of a population • Interpret health information meaning full • To plan and deliver health care service effectively
- 2. Definition • It is a scientific description of the characteristics of population, structure and changes which can be measured numerically. This involves primarily the measurement of the size of population(how many people they are),
- 3. composition (what the characteristics, such as sex and age of the people), distribution (where the people in the region are), and changes in the numbers of people .The main demographic processes which lead to changes in the number of people and composition of a population are fertility,mortality and immigration
- 4. POPULATION COMPOSITION • The composition of a population can be described in terms of factors such as age, sex, occupation, income, race or ethnicity, education and literacy. • The population composition determines to a large extent the types of health problems experienced and which health services have to be delivered
- 5. population pyramid • A population pyramid is a useful summary representative of certain aspect of population composition
- 6. Definition of population pyramid • It is a graphical display of percentage composition of a population by age and sex. Age is usually grouped in five year intervals. The percentages are represented by proportionately drawn horizontal bars. By convention, the percentage relating to the males are drawn on the left of the pyramid
- 7. And the females on the right. The age groups are drown from the youngest at the bottom of the pyramid to the oldest at the top. The shape of the pyramid is influenced by births, deaths and migration on the population.
- 8. • A developing country with high birth rate and low life expectancy will have a birth rate and low life expectancy will have a high proportion of young people and therefore, a population pyramid with a triangular shape and a broad base.
- 9. • On the other hand, a developed country with higher life expectancy, will have a higher percentage of people in the older age groups and therefore population pyramid with narrow base and steeper side. Events such as famines,wars,or mass migration in the recent past will
- 10. Will be reflected in the shape of pyramid. Population growth Three processes determine the changing of a population( fertility, mortality and migration) The balance between these three determines whether a population increases, decreases or remains stable in size.
- 11. CENSUS • Definition- this is the head counting of all people in a locality be it a country. As for Zambia it is done every 10 years.
- 12. Reasons for census • Government require information for planning and development, therefore many people are interested in the information obtained in census.
- 13. Ways of conducting census • Earliest census was done by gathering people in one place. This worked well in small communities but can not be used on large scale. • Counting the houses in an area and multiplying by the average number of occupants per house has also been tried in many parts of Africa.
- 14. • This gives an approximately number of people in a community • This is not accurate on a larger scale but is sometimes useful for making a quick estimate of a number of people in a village.
- 15. • Nowadays, enumerators going from house to house asking for information from head of the households is the approach most commonly used in taking a population census. In carrying out the census, either of the following methods are used.
- 16. • Firstly counting all people in the place they are found during census also called the de facto approach, and secondly, enumerating all people from their usual place of residence which is technically referred to as the de jure approach.
- 17. • Generally a population census is a very expensive undertaking and therefore carried out after every 10 years.
- 18. DEMOGRAPHIC RATES • Crude birth rate-This is a number of live birth per 1000 persons in the population. This measure require only total birth rates and total population. It is ‘crude’ measure in epidemiological terminology because it does not take in to account the age or sex structure of the population.
- 19. • NO of live births during yearX1000 Total population
- 20. Crude death rate • It expresses the number of deaths per 1000 population OR • No of deaths during a specified period X 1000 No of persons at risk of dying during the same period. OR Total no// of deaths during the yearX1000 Total population
- 21. • The main disadvantage of crude dearth rate(crude mortality rate)is that it does not take in to account the fact that the chance of dying varies according to Age, Sex, Socio- economic class and other economic factors.
- 22. INFANT MORTALITY • It measures the rate of death in children during the first year of life. • The denominator being the number of live births in the same year. OR
- 23. • It is one of the most universally accepted indicator of the level of health status not only of infants, but also of the whole population and socio-economic conditions under which they live.
- 24. • In addition, the infant mortality rate is a sensitive indicator of the availability , underutilization and effectiveness of health care services, particularly perinatal care
- 25. • Number of deaths under the age of one year divided by the number of live births in a given year expressed as a rate per 1000 live births. • No// of deaths in a year of children less than 1 year of age X1000 No// of live births in the same year
- 26. CHILD MORTALITY • The child mortality rate(under 5 rate) is based on deaths of children aged 1 up to 4 years and some months, but before 5 years It is also used as a base of health indicator. Injuries, malnutrition and infectious diseases are common causes of death in this group. It excludes infant mortality
- 27. • It is described as the probability (expressed per 1000 live births ) of a child dying before reaching the age of 5 years. • No//of deaths under 5 years of age X1000/ 10000 Total number of population of children below 5 years
- 28. Maternal (puerperal)Mortality Rate • The maternal mortality rate refers to the risk of mothers dying from causes associated with delivery of babies, complications of pregnancy or childbirths. This important statistic is often neglected because it is difficult to calculate accurately
- 29. number of maternal deaths from puerperal causes in a given geographic area during the year X10n • Number of live births that occurred among the population of a given geographical area during the same year.
- 30. • Maternal mortality accounts for the greatest proportion of deaths among women of reproductive age in most of developing world,.