Growing up in Scotland: overweight obesity and activity

CHAPTER 8 APPENDIX

8.1 Descriptions of measures used

This section provides a brief description of measures used as predictors, where these were derived from more than one measure supplied by ScotCen in the original data sets for sweeps 1 to 6 of the GUS birth cohort.

8.1.1 Child characteristics

Birthweight reported by mothers at sweep 1 was standardised for gender, gestational age and parity using tables recently published for Scottish infants (Bonellie et al. 2008). Gestational age was based on mother's reports at sweep 1.

8.1.2 Maternal characteristics

Mother's mental and physical health were based on the SF12 measure of mother's physical and mental health at sweeps 1, 3 and 5. Mean scores were calculated for physical and for mental health over these three sweeps, and scores were divided into tertiles (poor, medium, good health).

8.1.3 Family characteristics

Household income: the average quintile of equivalised household income across the first five sweeps of data collection was calculated from quintiles derived at each sweep (range 1 to 5). Mean scores were then divided once more into quintiles.

Lone parent indicated whether the child's biological father did not reside in the household at one or more of sweeps 1 to 6.

8.1.4 Parenting

Frequency of sweet and crisp consumption at sweep 2 was recorded using two questions:

How often does [childname] eat sweets or chocolates? How often does [childname] eat crisps or other savoury snacks? Answers were recorded on a 9-point scale:

1 6 or more times a day
2 4 or 5 times a day
3 2 or 3 times a day
4 Once a day
5 5 or 6 times a week
6 2 to 4 times a week
7 Once a week
8 1 to 3 times per month
9 Less often or never

Initial exploration did not show differences in children's overweight or obesity with responses less than 5 or 6 times a week, for either type of snack. A combined measure was derived from both items, indicating whether the child had sweets and crisps more than once a week, either sweets OR crisps more than once a week, or neither more than once a week.

Room where child eats main meal was based on questions asked at sweeps 2 and 5. Responses were divided into those where the child ate a main meal in the kitchen, dining room or combined living/dining room at both of these sweeps, those where these rooms were used at one of the sweeps, and those where the child did not eat in a room designed for food consumption at either sweep.

Warmth of mother-child relationship was measured at sweep 5 using seven items from the Pianta scale (Pianta 1992) (reliability acceptable, Cronbach alpha=0.67). Each item was scored as 1 definitely does not apply, 2 not really, 3 neutral, 4 applies sometimes, or 5 definitely applies. "Can't say" responses were considered as missing. Scores were summed for parents who had completed all warmth items. A high number of parents scored the maximum of 35, and so parents in the lowest tertile (7-33) were contrasted with the remainder (medium/high warmth).

Joint activities (carried out by mother and child together) were measured at sweeps 2, 3 and 4. A count of the number of activities that the mother had carried out with the child in the past week was made for each of sweeps 2-4 (from a list of six: books/stories, played outdoors, painting or drawing, nursery rhymes or songs, letters or shape recognition, used a computer or games console). Mean scores were computed and divided into tertiles: low (0 to 3 activities), medium (4 activities) and high (5 or 6 activities).

Parental supervision was measured at age 4 using an abbreviated version of the Parent Supervision Attributes Profile Questionnaire (Morrongiello and Corbett 2006). Mothers were asked for their agreement with statements covering protectiveness ("I feel very protective of my child", "I think of all the dangerous things that could happen", "I keep my child from playing rough games or doing things where he/she might get hurt") and supervision while the child plays outdoors ("I can trust my child to play by (him/herself) without constant supervision", "I stay close enough to my child so that I can get to him/her quickly", "I make sure I know where my child is and what he/she is doing") Answers were coded on a 5-point scale from 1=strongly agree to 5=strongly disagree. Item 4 was reverse-coded, and a mean score of the six items (Cronbach's alpha=0.67, indicating acceptable reliability) was computed and divided into tertiles of low, medium and high parental supervision.

Rules and routines were measured at sweeps 2 and 5. A count of number of "rules" or routines was derived from the following: 'always' responses to question on regular meals at sweep 2, a question on regular bedtime at sweep 5 and four questions at sweep 5 on whether child had to tidy up toys, brush teeth, stay in room and turn off TV or music in room (using 4-point scale (always/usually/sometimes/never or almost never). The number of rules was banded into low (0-3 rules), medium (4-5 rules) or high (all 6 rules).

Home chaos was measured sweep 5. This was an abbreviated version of the confusion, hubbub, and order scale (Coldwell et al. 2006), devised as a measure of household disorganisation. A number studies suggest that household disorganisation may impair effective parenting (Coldwell et al. 2006; Valiente et al. 2007; Deater-Deckard et al. 2009; Mokrova et al. 2010). Mothers were asked for their agreement with four statements. This was measured from 5-point scales of agreement with four items (Cronbach alpha=0.63, indicating acceptable reliability): "It's really disorganised in our home", "You can't hear yourself think in our home", "The atmosphere in our home is calm" and "First thing in the day, we have a regular routine at home". The first two items were reverse-coded. Mean scores were divided into tertiles, indicating low, medium and high levels of chaos.

8.1.5 Neighbourhood characteristics

Child-friendliness was based on mothers' level of agreement with six statements at sweep 3: "People around here look out for each other's children", "Most people around here can be trusted with children", "People around here hold shop doors open for parents with pushchairs", "Bringing up children well is a priority for people in this area" and "This is a good area to bring children up in". Answers were recorded on a 5-point scale from "strongly agree" to "strongly disagree". Reliability was good (Cronbach alpha 0.80). Mean scores were used.

Neighbourhood safety was measured from mothers' level of agreement at sweep 3 with two statements: "I feel safe when I am out alone in this neighbourhood during the day" and "I feel safe when I am out alone in this neighbourhood after dark" (responses were on a 5-point scale from "strongly agree" to "strongly disagree"). Average scores were calculated, and divided into those above and below the mean (high versus low perceived safety).

Antisocial behaviour was a score of the number of different types of antisocial behaviour occurring in the neighbourhood in the past year, reported by mothers at age 6. Behaviours were prompted using a showcard, and covered:

Noisy neighbours or regular loud parties
Vandalism, graffiti or other deliberate damage to property
Rubbish or litter lying around
Neighbour disputes
Groups or individuals intimidating or harassing others
Drug misuse or dealing
Rowdy behaviour, e.g. drunkenness, hooliganism or loutish behaviour
Abandoned or burnt-out vehicles

Responses were coded into 0, 1, 2, 3 or 4 or more such behaviours.