Population change - Methodology

 

Population change

Population in given area is changing over the time in its size and structure. Population change is driven by demographic events which are happening to inhabitants during a year. The most key events are described below but for demography purposes only the information about events of inhabitants of the Czech Republic are used. 

Demographic events:

Marriages

The Czech Statistical Office receives information about the number of legally marriages entered into from the reporting unit (Registry Office)1, which is obliged to send statistical reports on marriage. This report includes information about age, marital status, citizenship and educational attainment2 of engaged couples, marriage order and the date of previous divorce or widowhood and others. In terms of territorial division, marriages are classified by the place of residence of the groom. 

Divorces

It is observed the number of dissolution of marriages on the basis of statistical reports on divorce, which are sent by reporting unit (the court). The data on divorces has been provided to the Czech Statistical Office electronically through the information system of the Ministry of Justice of the Czech Republic since 2007. Divorce statistics gives information about age, educational attainment2, citizenship, number of minors, cause of marriage breakdown on the part of male and female, date of marriage and divorce order and others. In terms of territorial division, divorces are classified according to the last common residence of married couple. In terms of time, until 2006 divorces were classified by the date when the report on divorce was sent off, since 2007 the date when the divorce comes into force has been used (this characteristic has not been at disposal previously).

Births

It is observed the number of total births (live births and stillbirths) on the basis of statistical reports on birth, which the Czech Statistical Office receives from the reporting unit (Registry Office). This report includes information about sex, vitality, birth weight, length and birth-order (in total and in current marriage) of the infant, marital status of mother and about age, education attainment2, citizenship, country of birth of parents so as the date of parent’s marriage and others. In the terms of territory division, births are classified according to the residence of mother at the time of delivery.

On the 1st of April 2012, a regulation No. 11/1988 Coll. of the Ministry of Health of the CSR, which defined a live birth and stillbirth, was cancelled by Act No. 372/2011 Coll. The previous regulation defined live birth and stillbirth as follows:

“A live birth is the complete expulsion or extraction from its mother of a child provided that the child shows at least on sign of life and its birth weight is: a) 500 g or more, or b) lower that 500 g and if it survives 24 hours after delivery. The signs of live are: breathing or beating of the heart or pulsation of the umbilical cord, or movement of voluntary muscles, although the umbilical cord has not been cut or the placenta has not been delivered.”

“A stillbirth is the complete expulsion or extraction from its mother of a foetus that shows no sign of life and its birth weight is 1000 g or more.”

General definitions of terms live birth and stillbirth are not contained in the currently valid legislation (October 2014). These definitions along with all case of abortions are stated only in the guidelines for filling in the “Death certificate (Report on examination of the deceased person)“ (in the regulation No. 297/2012 Coll.), namely for the needs of filling in of the Death certificate (Report on examination of the deceased person). A stillbirth is also defined in the Commission Regulation (EU) No. 328/2011 implementing Regulation (EC) No. 1338/2008 of the European Parliament and of the Council on Community statistics on public health and health and safety at work, as regards statistics on causes of death, namely for the purposes of the regulation.

Abortions

Data on abortions are compiled from a set of individual data received from the Institute of Health Information and Statistics of the CR (further “the Institute”). Related nomenclatures (more detailed for the marital status and education of woman than those used on reports of the Czech Statistical Office) are applied in the processing without any adjustment. The ectopic pregnancies were included under induced abortions in 1988-1991, and since 1992 under other abortions. Abortion is possible to classify according to the type of abortion, gestation age of the foetus, age and marital status of women or the number of previous abortions and live births of women and others. 

On the 1st of April 2012, a regulation No. 11/1988 Coll. of the Ministry of Health of the CSR, which defined an abortion, was cancelled by Act No. 372/2011 Coll. The abortion was defined as follows:

“An abortion is the termination of a pregnancy of a woman, at which: a) the foetus does not show any sign of life and its birth weight is below 1000 g and in case the weight cannot be measured, if the pregnancy lasts less than 28 weeks; b) the foetus shows at least one of the signs of life and its birth weight is below 500 g, but it does not survive 24 hours after delivery; c) the foetal egg without a foetus or deciduas was removed out of the female’s uterus. Cases of termination of ectopic pregnancy or induced abortion carried out as stipulated in special regulations are also considered as abortions.”

The Act No. 372/2011 Coll. defines foetus after abortion, which is a foetus, which after the complete expulsion or extraction from its mother shows none of the signs of life and at the same time its birth weight is lower than 500 g and provided that the weight cannot be measured, if the pregnancy lasted less than 22 weeks.

Cases of termination of ectopic pregnancy or induced abortion carried out as stipulated in special regulations are also considered as abortions.

Deaths

It is observed the number of total deaths on the basis of statistical reports on death, which the Czech Statistical Office receives from the reporting unit (Registry Office). Since 2013, a part A of the Report on examination of the deceased person (defined in the regulation No. 297/2012 Coll.) is the primary source of data for filling statistical Report on death by Registry Office. Related nomenclatures (more detailed for the marital status than those used on reports of the Czech Statistical Office) are applied in the processing without any adjustment. Deaths are classified according to age, sex, marital status, education attainment2, citizenship, country of birth, cause of death and others. The place of death has been observed since 2007.

Since 1st January 1994, causes of death are classified according to the 10th decennial revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) with its further updates issued by the World Health Organization (WHO). The Institute of Health Information and Statistics of the Czech Republic is responsible for the use of ICD-10 in practice. Since 2011, selection of underlying cause of death has been made by a programme for automated coding (IRIS). For processing the statistics by causes of death since 2013, the Institute has transmitted to the CZSO a part B of the Report on examination of the deceased person, which contains the causes of death.

 

Migration (immigrants, emigrants)

Migration is defined as a change of permanent residence or long-term residence beyond the border of given territorial unit. Two types of migration are distinguished: internal (within the Czech Republic) and external (international).

For demography purposes, migrants are specified by age, marital status and citizenship. Migration is specified itself by the date of migration, previous and new residence. It was surveyed also the reason of migration until 2004.

The data on migration were taken from the reports on migration (reporting units were Registration offices of residence and district offices of the Foreign and Border Police of the Czech Republic) between the years 2001 and 2004. Since 2005 they have been electronically taken from the Ministry of Interior. The Directorate of Alien Policy was the main source of data in case of migration of foreigners in the period 2001-2007 and it is again from July 2012.

Main demographic indicators:

Total pregnancies
The sum of all live births, stillbirths and abortions.

Premarital conceptions
The share (in %) of first order births less than 8 months after marriage out of the total number of first children in current marriage.

Natural increase
The difference between the number of live births and total deaths for the same period in a given area.

Net migration
The difference between the number of immigrants and emigrants for the same period in a given area.

Total increase
The sum of natural increase and net migration for the same period in a given area.

Gross of external migration
The sum of the numbers of immigrants from abroad and emigrants abroad.

Volume of internal migration
The numbers of all register cases of internal migration in given territorial unit and given time period. Volume of internal migration for higher territorial unit is defined as the sum of volume of internal migration of lower territorial units plus migration between the lower territorial units.

Sex ratio
The number of men in relation to women (usually expressed per 100 women). This indicator could be given for a total population or for different age groups in given time. Secondary sex ratio is defined as the ratio of live born boys and girls in given time period.

Index of ageing
The relation between the old age population over 65 and the young population under 15 in a given time. It is expressed as the number of person aged 65+ per hundred persons aged 0-14.

Total dependency ratio
The number of children (0-14 years old) and older person (65 years or over) per the population (usually per hundred persons) in economic activity age (15-64 years old).

Average age
The arithmetic average of age of all the members of a population (either specific gender or total) living in a given time in a given territory.

Median age
The age that divides a population into two numerically equal groups; that is, half the people are younger than this age and half are older.

Life expectancy
The expected remaining life duration of person (separately males and females) at given age provided unchangeable mortality conditions of a given year. It is one of the most important indicator in life table.

Gross rates (marriages, divorces, births etc.)
The relation between the number of given demographic event and the number of inhabitants. The rates are usually expressed per 1,000 inhabitants. The population used for calculation of rates is the mid-period population at for a given area and time.

Total fertility rate
The average number of children that would be born alive to a woman provided that age-specific fertility rates of a given year remain unchanged during her childbearing period (age 15-49).

Gross reproduction rate
The average number of girls that would be born alive to a woman provided that age-specific fertility rates of a given year remain unchanged during her childbearing period (age 15-49).

Net reproduction rate
The average number of girls that would be born alive to a woman and will survive until the age of her mother at the time of delivery provided that age-specific fertility and mortality rates of a given year remain unchanged during her childbearing period (age 15-49).

Total abortion rate
The average number of abortions per woman provided that age-specific abortion rates of a given year remain unchanged during her childbearing period (age 15-49).

Total first marriage rate
The proportion of men, respectively women that would be entered into the first marriage before the age of 50 provided that age-specific marriage, mortality and unmarried migration rates of a given year remain unchanged.  

Total divorce rate
The proportion of marriages that would be terminated in divorce provided that divorce rates by duration of marriage recorded in a given year remain unchanged.

Stillbirth rate
The number of stillbirths per 1,000 total births.

Infant mortality rate
The number of deaths under 1 year of age per 1,000 live births.

Neonatal mortality rate
The number of deaths under 28 days of age per 1,000 live births.

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1 Reporting unit (Registry Office) is obliged to record all events that happen in the territory of its administrative district. The events, which happened to citizens of the Czech Republic abroad, are treated by special Registry Office in Brno.

2 Provision of the information about education attainment is voluntary.