Data Issues

Waves 1 to 7
Data issues - Waves 1 to 7 – February 2019

14 Date of birth corrections

At each interview, or between interviews, parents may advise us of a correction to the date of birth of anyone in the household (usually the study child). These are reflected in the items zf04mx, where x is the member number. So zf04m1 would be the variable for the SC for this example.

In addition to these updates, staff from the Murdoch Children's Research Institute noticed some date of birth discrepancies (compared to LSAC recorded date of birth) while conducting the Child Health CheckPoint (CHCP) sessions.

Due to the quite robust nature of the checkpoint process for obtaining and checking date of birth, the ABS has investigated these discrepancies (including calling the participant in some cases) and updated the LSAC date of birth in the Wave 7 Household file where appropriate.

There has been a total of 82 changes to study child date of birth since Wave 1. To assist users in identifying these records, an additional indicator variable has been added to the Household file and the data dictionary. It has been linked with the household member number to maximise its usefulness. The variable is zf04am*. Users can enter desired member number at * to return the data required (e.g. M1 for SC, M2 for P1 and M3 for P2).

Table 31 shows the magnitude for those changes and if the change came during Waves 1-6 (or from the CHCP data checks).

Table 31: Shows changes to study child date of birth during Wave 1 to 6 (or from the CHCP data check)
Date of birth change Number of SC records corrected during Waves 1-6 Wave 7 from CHCP Total
Less than 1 month 43 4 47
1 month < 3 months 15 2 17
3 months < 6 months 10 0 10
6 months < 12 months 5 0 5
12 months or more 3   3
Total 76 6 82

Wave 7 corrections have been made and any derived variables affected have been calculated using the correct date of birth. Wave 1–6 updates have been made to the datasets so that any derived variables affected by a change to date of birth have now been re-derived using the correct date of birth. The only exception to this is the Academic Rating Scale (ARS) data items. These have not been updated for Waves 1–6 due to a cost–benefit decision. Users of these data can make use of the new date of birth change indicator variable to exclude records if necessary.