Data Issues

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

12 Missing data for Wave 6 items

12.1 Missing data for bullying items

In the Wave 6 ACASI instrument B cohort children were asked ACASB 6.1:

During the last 12 months, since [current month inserted] last year …

a. kids hit or kicked me on purpose

b. kids grabbed or shoved me on purpose

c. kids threatened to hurt me

d. kids threatened to take my things

e. kids said mean things to me or called me names

f. kids tried to keep others from being my friend

g. kids did not let me join in what they were doing

h. kids used force to steal something from me

i. kids hurt me or tried to hurt me with a weapon

j. kids stole my things to be mean to me

k. kids forced me to do something I didn't want to do

l. I hit or kicked someone on purpose

m. I grabbed or shoved someone on purpose

n. I threatened to hurt someone

o. I threatened to take someone's things

p. I said mean things to someone or called someone names

q. I told others not to be someone's friend

r. I did not let someone join in what I was doing

s. I used force to steal something from someone

t. I hurt or tried to hurt someone with a weapon

u. I stole someone's things to be mean to them

v. I forced someone to do something they did not want to do

For selected categories children are then asked ACASB 6.5

How did this happen?

You can select more than one. (If you are not using a mouse, press space bar between responses.)

1.Face-to-face

2. Video chat

3. Phone call (not video chat)

4. Private messaging (includes email)

5. Open forum (e.g. Facebook walls, blogs, Twitter)

6. Other

Due to a sequencing error ACASB 6.5 was not asked for the following response categories of ACASB 6.1:

k. kids forced me to do something I didn't want to do

n. I threatened to hurt someone

o. I threatened to take someone's things

p. I said mean things to someone or called someone names

q. I told others not to be someone's friend

r. I did not let someone join in what I was doing

s. I used force to steal something from someone

v. I forced someone to do something they did not want to do

Thus, these items are not on the output file for the B cohort. The K cohort was not affected by this sequencing error.

12.2 Missing data for Cogstate items

In Wave 6, the K cohort study children were given tasks to assess executive functioning. Three tests were included:

  • Identification task (testing visual attention and choice reaction time); for example, press Yes if card is Red, No if card is Black.
  • One back task (testing working memory); for example, press Yes if current card is the same as the previous card, No if different.
  • Groton Maze (spatial memory, impulse control and inhibition of erroneous responses); for example, trying to work out the correct path through a maze and remembering it for the next time through.

For some of the Wave 6 interviews, systems issues resulted in a small number of records with no executive functioning data on the output file. As Table 26 shows, the item hid40o1 indicates whether the executive functioning data are present and a reason for those records where the data are not present.

Table 26: Whether Cogstate data present - K cohort
14/15 - EXF- Cogstate data present - hid40o1 Number of records %
Not applicable (-9) 146 4.1
Cogstate data present 3,234 91.4
Cogstate data not present - no consent given 43 1.2
Cogstate data not present - module could not be completed due to systems issues 83 2.4
Cogstate data not present - data loss due to systems issues 29 0.8
Cogstate data not present - child consented but did not complete any tasks 2 0.1

12.3 Missing data for puberty-related items

In Wave 6, all K cohort female study children were asked for the first time if they have ever menstruated (had your period). If they answered yes, then they were asked about age of first period, any periods in the last three months, and menstrual problems in the last three months. These questions were asked as part of the audio-computer-assisted self-interview (ACASI).

In previous waves, the P1 was asked whether the study child had ever menstruated and the age of first period. These questions were asked as part of the computer-assisted self-interview (CASI) mode of the interview.

In Wave 6, a roll forward error in the instrument meant not all eligible children (those who reported at Wave 6 that they had started their period) were asked the subsequent questions about age started period and period experiences in the last three months. Those cases where the P1 had previously reported that the study child's periods had started (n = 876) were not asked these additional questions.

Further, a sequencing error resulted in some study children (n = 85) being asked if they had a period in the last three months even though they answered 'no' to ever had a period.

The Wave 6 data were presented as collected from the study child. Items combining information collected from the two different informants have not been derived. Further, no data were amended when answers between the two informants conflicted or answers from the same informant conflicted. For example, when P1 reported that the study child's period had started, but the study child reported it hadn't, and when the study child reported they hadn't started period, but then reported one in last three months.

Table 27 presents the various items that could be used for analysis of this topic. Only K cohort items are presented given B cohort study children were not asked these questions in Wave 6.

Table 27: Study child menstruation items
Wave Variable Name Variable Label Mode Informant Number missing
5 ghs36h 12/13 - CASI D4.7+W4 - Menstruate CASI Parent 1 NA
5 ghs36h1 12/13 - CASI D4.8+W4 - Menstruate (total months) CASI Parent 1 NA
6 hhs36h 14/15 - SC - ACASK 18.2 - Menstruate ACASI Study child NA
6 hhs36h1 14/15 - SC - ACASK 18.3 - Menstruate (total months) ACASI Study child 876
6 hhs36i 14/15 - SC - ACASK 18.4 - Have you had any periods in the last 3 months ACASI Study child 876
6 hhs36i1 14/15 - SC - ACASK 18.5.1 - How regular were your periods ACASI Study child 876
6 hhs36i2 14/15 - SC - ACASK 18.5.2 - How heavy were your periods ACASI Study child 876
6 hhs36i3 14/15 - SC - ACASK 18.5.3 - How painful were your periods ACASI Study child 876
6 hhs36i4 14/15 - SC - ACASK 18.5.4 - How grumpy or teary did you get before your periods ACASI Study child 876
6 hhs36i5 14/15 - SC - ACASK 18.6.1 - Did you miss any school days ACASI Study child 876
6 hhs36i6 14/15 - SC - ACASK 18.6.2 - Did you miss any social activities ACASI Study child 876
6 hhs36i7 14/15 - SC - ACASK 18.6.3 - Did you miss any sports or exercise ACASI Study child 876

12.4 Missing data for study child helping others items

In Wave 6, K cohort study children were asked about helping others. More detailed questions about these caring situations were subsequently asked for up to three people. These questions were asked as part of the audio-computer-assisted self-interview (ACASI).

When study children entered more than three people when asked who they helped (e.g. Paul John George Ringo, instead of just Paul John George), the instrument was unable to process who to ask the subsequent questions about and as a result these questions were not asked (n = 132).

Table 28 lists the items affected and the counts. The second and third set of items were also set to missing, given it is unclear how many people the study children may have helped.

Table 28: Amount of missing data for study child helping others items
Variable Name Variable Label Number missing
hsc28a 14/15 - ACASK 12.1 - Help someone with long-term health condition/disability/elderly NA
hsc28b1 14/15 - ACASK 12.3.1 - What is first person's relationship to you 132
hsc28b2 14/15 - ACASK 12.4.1 - Does first person live with you 132
hsc28b3 14/15 - ACASK 12.5.1 - Does first person go to the same school as you 132
hsc28e1 14/15 - ACASK 12.6.1.1 - Help provided - 1st person - Personal care 132
hsc28f1 14/15 - ACASK 12.6.1.2 - Help provided - 1st person - Moving around 132
hsc28g1 14/15 - ACASK 12.6.1.3 - Help provided - 1st person - Transport 132
hsc28h1 14/15 - ACASK 12.6.1.4 - Help provided - 1st person - Communicating 132
hsc28i1 14/15 - ACASK 12.6.1.5 - Help provided - 1st person - Preparation of meals 132
hsc28j1 14/15 - ACASK 12.6.1.6 - Help provided - 1st person - Housework/shopping/errands 132
hsc28k1 14/15 - ACASK 12.6.1.7 - Help provided - 1st person - House repairs/garden care 132
hsc28l1 14/15 - ACASK 12.6.1.8 - Help provided - 1st person - Health care 132
hsc28m1 14/15 - ACASK 12.6.1.9 - Help provided - 1st person - Paperwork 132
hsc28n1 14/15 - ACASK 12.6.1.10 - Help provided -1st person - Keeping them company 132
hsc28o1 14/15 - ACASK 12.6.1.11 - Help provided -1st person - Other 132
hsc28q 14/15 - ACASK 12.8 - How often do you do these caring activities Not affected as not in a loop
hsc28r 14/15 - ACASK 12.9 - On average - total number of hours you spend providing care Not affected as not in a loop