The DSS is meant to track DSS members in their location as specific point in time. The location- residency information of DSS members is stored in RESIDENCY table. This table is created in the background when information about core events entered computer. This table is used to compute person-years lived for DSS members. Before computing person-years lived, it is important to check consistency in residency table. The following checks should be made.

People become DSS members through enumeration (mainly at the initial census), migration and births to DSS members and cease to be DSS members through out- migration or death. Because tracking of location residency within the DSA is so crucial to continue monitoring of core events that occurred to DSS members, change of residency (ENTRY to new location or EXIT from location) events are also of interest. Therefore, in the residency table ‘start event type’ refers to ENUMERATION, BIRTH, ENTRY OR IN- MIGRATION, and ‘end event type’ refers to DEATH, EXIT OR OUT- MIGRATION. Although the date of end event type is expected to refer to a more recent date than the date of ‘start event type’ that opened the residency episode, sometimes this expectation may not hold true due to error in data storage or data cleaning procedures. It is important to check if date of end event type refers to a most recent date than date of start event type.  

Because the residency table is created when data for any of the start/end event type are recorded, the number of each event type and the date when each event type occurred should be the same as the number of specific event that is registered and the date that each event occurred in the corresponding event table. In other words, the total count of birth from the birth table should be equal to the number of records with BIRTH as start of event type in RESIDENCY table. The date of birth from the birth table should also be identical to the start date of the BIRTH record for the corresponding person. It is absolutely crucial to establish consistency between each event table and the corresponding table from residency table once data are stored in the system. Discrepancy could be due to bug in programming or cleaning processes. Please consult a do-file used by the African Population and Health Research Center to compare the residency and event tables. (Stata Routine Residency event check do file.do)