The Dabat Research Center aims to generate longitudinal data on vital events (birth, death, migration, and marital status changes) and identifies cause of death using verbal autopsy method. To address these objectives, the center performs three basic operations: 1) A baseline census that defines the study population, 2) A re-census to update some variables (e.g. education, household assets, and occupation) which are not collected and updated during the regular visit of households, and 3) Population updates to capture vital events.
1) Baseline Census
The baseline census was conducted in 2008 aiming to establish the foundation for a longitudinal surveillance system and to obtain background data on the study population. In the baseline census, a data collection tool was used to collect baseline information on household location, demographic characteristics, housing condition and socioeconomic conditions.
The following minimum data were collected during the baseline survey:
- Location-related
- – District
- – Kebele
- – Altitude, longitude, and latitude of the place where the household is located
- Household-related
- – Housing characteristics (roof and floor construction, availability of windows, source of energy, cooking inside house, animal living inside the house…)
- – Head of the household (Sex of the head of the household)
- – List of household members
- – Household monthly income
- Individual-related
- – Relation to the head of the household
- – Date of birth
- – Sex
- – Individual ID
- – Marital status
- – Age at first marriage
- – Education status
- – Occupation
- – Religion
- – Ethnicity
- Birth-related
- – Birth during the past one year
- Age of the mother when she gave birth
- Sex of the infant
- Place of birth
- Birth attendant
- Morbidity-related
- – Number of people who were sick during the past two weeks
- – Age of the patient
- – Sex of the patient
- – Signs and symptoms these sick people were having
- – Whether the patient visited a health institution for his/her illness
- – Perceived cause of illness
- – Presence of injured people in the household
- – Type of injury
- Death-related
- – Death during the past one year
- – Sex of the deceased
- – Date of death
- – Age at death
- – Place of death
- – Perceived cause of death
2) Re-census
Re-census is performed to update some variables (e.g. education, household assets, and occupation) which are not collected and updated during the regular visit of households. It is also used to validate what is collected during regular visit and to check whether there is missed data or events. a similar data collection tool to that of the baseline census is used to collect re-census-related information.
3) Population Update
After the baseline census where all households and members of the HDSS sites are registered, each household is visited and updated every six months to track events (death, birth, migration, and marital status changes) and update the population. In addition, information that helps to identify cause of deaths are collected.
Updating of vital events is not the only activity carried out during these periodic visits. During update rounds, field workers register new people or households. These include the migrants, the newly married, and any individuals missed during the initial census.
Vital events registration forms are used to capture demographic and health events like, pregnancy observation and outcomes, deaths, marriages, and in and out migration. These forms are used for the identification and recording of all events by the field workers in collaboration with local guides and field supervisors. These forms are used at the time of house-to-house visits every six months. In addition to the vital event registration forms, a standardized WHO verbal autopsy questionnaire is used to gather information to determine cause of death.
The following minimum data are being collected during the population update:
- Pregnancy observation and outcome of pregnancy during the previous round time frame
- – Mother ID
- – Last Menstrual Period (LMP)
- – Whether she was attending ANC by the end of the previous round
- – Duration of pregnancy (in completed weeks) when ANC started
- – Whether she received TT vaccination
- – Frequency of TT vaccination in the current pregnancy
- – Outcome of the pregnancy (abortion, stillbirth, live birth)
- – Date the outcome occurred
- – Place of delivery (for stillbirth & live birth)
- – Sex of the newborn (for stillbirth & live birth)
- – Birth attendant (for stillbirth & live birth)
- – Number of births
- Death-related (during the previous round)
- – Sex of the deceased
- – Date of death
- – Place of death
- – Whether that person sought medical care before the death occurred
- – Perceived cause of death
- – Cause of death using Verbal Autopsy method
- Internal In-migration (between *Kebeles within the surveillance area/site)
- – Date of internal In-migration
- – Place of previous residence (Kebele)
- – Household ID of previous residence
- – Individual ID when he lived in the previous residence
- – Name of the household head of the house he/she moved in
- – Household ID of the house he/she moved in
- – Relation with the head of the household
- – Reason for in-migration
- Internal Out-migration (between Kebeles within the surveillance area/site)
- – Date of internal out-migration
- – Household ID of the house where he/she was living
- – Individual ID
- – District where he/she migrates to
- – Kebele where he/she migrates to
- – Name of the household head where she/he migrate to
- – Reason for out-migration
- External In-migration (to the surveillance area/site)
- – Date of External In-migration
- – Region of previous residence
- – Zone of previous residence
- – District of previous residence
- – Kebele of previous residence
- – Name of the household head of the house he/she moved in
- – Household ID of the house he/she moved in
- – Relation with the head of the household
- – Reason for external in-migration
- – Sex
- – Date of birth
- – Ethnicity
- – Religion
- – Education
- – Marital status
- – Occupation
- External Out-migration (outside the surveillance area/site)
- – Date of external out-migration
- – Country where he/she migrate to
- – Region where he/she migrates to
- – Zone where he/she migrates to
- – District where he/she migrates to
- – Reason for out-migration
*Kebele is the smallest administrative unit in Ethiopia