Sources of Data on Vital Statistics

The main sources of data on vital statistics are : 

1. Census 
2. Population Registers 
3. Sample Registration Scheme 
4. National Sample Surveys 
5. Health Services Records 
6. Special Surveys 
7. Disease Registers 

Before learning more details about each of these sources, you should remember that each of these sources have their own limitations and a country cannot solely depend on a single source. Usually information from various sources is compiled together to get vital statistics. 

Census 

Let us first define the meaning of the term  "Census".  Census means complete counting of all individuals/houses (individuals-population-Census; houses- housing-Census) in a country on a fixed data preferably once in 10 years. Census provides information on age, sex, religion, occupation, literacy, income etc. of the population. The first census in our country took place in 1872 and subsequently it is being conducted once in ten years. In India the latest census was held on 1st March 1991. 

How do you think the population census can help in computing vital statistics/rates for a country? As you read this unit further, you will realize that the population census provides useful basic information for calculating vital rates. Similarly, housing census helps to analyse environmental conditions (such as water supply, toilet facilities, availability of space per person, etc.). 

Population Registers 

In some countries, such as Sweden, Finland, Belgium, Israel, Taiwan and Korea, data about population can be obtained from continuously maintained population registers, in which the name of each person in the country is entered. Important migratory movements of individuals are also registered. The primary objective of setting up this system of population registers is to establish the identity of individuals and control them. The registers, however, are also used to obtain such demographic information as current population size, internal migration, data on vital events, etc. 

Sample Registration Scheme 

As you know, in every community records of births, deaths and marriages are kept by either the local authorities or by religious'leaders. If these records are complete and kept systematically,  they can be used for estimation of fertility, mortality and marriage rates. 

However, there is one limitation. In our country these records are usually not complete. This is because of ignorance, illiteracy, indifference and poor systems of management. There is no incentive also to register deaths, births and marriages. Hence, people usually do not report these vital events promptly. Inspite of this, systematic analysis of these records do help to provide vital statistics of some public health significance. 

National Sample Survey

The main objective of the National Sample Survey has been to collect data on some important socio-economic aspects on a comprehensive basis for the whole country through its various rounds by using the technique of sample survey. The First Round of the National Sample Survey (NSS) was conducted in 1950; since then, information on different items has been collected through various rounds of the NSS. The topics covered so far include the following: fertility, mortality, population growth, economically active population, family planning, employment and unemployment, consumers, expenditure patterns, housing conditions, manufacturing industries, physically  handicapped persons. 

Health Service Records 

Information can also,be obtained from health service records kept by the health sector for  administrative purposes (e.g. maternal mortality in hospitals, disease specific morbidity, information about birth weight, height during infancy and childhood arm circumference of children, information on immunization and prevention and control of certain endemic diseases). Though health service records provide useful data for vital statistics, they have their limitations unless kept properly. Their limitation is that they are kept for administrative purposes rather than monitoring purposes and that too only at places where health services are utilized. 

Special Surveys 

Household surveys undertaken by the members of a community, village agents, local officials or researchers are very useful in providing information on age-specific and disease-specific mortality. These (when carried out at the national level) are more frequently used for providing  information  for vital statistics/rates. 

Disease Registers 

Disease registers maintained by various hospitals provide data on mortality and morbidity  for selected specific diseases and the treatment given.