Restricción al emisor en relación a otros acreedores

In October 2009, the schools provided information about any participants who had left the school during the intervening period. All remaining Time 1 participants were contacted via the school and caregiver permission sought for the girl to take part in Time 2 data collection (see Appendix F). Two identical letters were sent, two weeks apart, and each letter was individually addressed to each girl and her family in an attempt to maximise response rates. Each letter comprised an information sheet about the study’s purposes, a recap of what was done at Time 1 and an invitation to provide consent for participation at Time 2. They were asked to return a tear-off slip confirming the child’s date of birth and providing the caregiver’s informed consent. Where consent forms were not returned, enquiries were made with the school to ascertain whether the child had left the area, was absent due to illness or had simply not returned a form. Of the 194 participants in Time 1 data collection, 138 participated in Time 2 data collection (70%).

All the psychometric measures used at Time 1 were used again at Time 2, and children were again anthropometrically measured for weight and height. Data collection proceeded as described in subsection 3.3, with the addition of two extra measures to complement measures of existing variables: a second measure of SES and a second measure of body dissatisfaction. The SES measure (the FAS II) is described in subsection 3.4.1. The second body dissatisfaction scale (the BMS) is described in subsection 3.4.2. Since the BMS was developed specifically for use in these projects, details of its development and validation process are given.

3.4.1 Family Affluence Scale II (Boyce, Torsheim, Currie, & Zambon, 2006).

The Family Affluence Scale II (FAS II; see Appendix J) is an index of relative family material deprivation that does not require parental input. This measure was introduced as an individual level measure of socioeconomic status to complement the existing school-wide figures for FSM uptake. Children, particularly those in primary education, tend to provide inaccurate and incomplete reports of their caregiver(s) socioeconomic status, such as occupational category or income (Currie, Elton, Todd & Platt, 1997). The FAS II achieves a higher response-rate and accuracy by asking children about simple, accessible elements of

everyday life, which reflect the affluence of their family. The FAS II also accommodates children living in non-traditional family structures by eliminating the emphasis on both maternal and paternal variables. It has been most widely used with children from age 11 but is suitable for children with a reading age of 6 to 7 years. It has been used in several large international studies such as the World Health Organisation Health Behaviour in School- Aged Children (HBSC) Survey (Currie, 2008).

The FAS II includes four item categories: participants are asked to endorse a sentence in each item category that best describes their family circumstances. One item category asks about the number of vehicles owned by the family, another whether or not the child has his/her own bedroom, another the number of family holidays in the last year and the last item the number of computers owned by the family. A composite score of the four items is produced, classifying the participant’s family affluence level as low (score 0,1 or 2), medium (score 3, 4 or 5) or high (score 6, 7, 8, or 9). Children’s endorsement of the scale items is reasonably consistent (κ = .41 - .74) with their parents’ endorsement of the same items (Andersen et al, 2008), whilst FAS II scores and paternal occupation show a modest (r = .35) association (Currie et al, 1997). Internal consistency estimates for the FAS II have tended to be low e.g. r = .31 (Boudreau & Poulin, 2009) and r = .35 (Lin, 2010). Currie et al (2008) have argued that the FAS, as a formative scale, has not been designed to tap a specific, narrow latent construct but rather to provide a summated index of wealth. As such, they have previously contend that high internal consistency values should not be expected.

3.4.2 Body Manipulation Software (Evans & Tovée, 2012).

At Time 2, participants’ body dissatisfaction was assessed using both the CBIS and a novel, unpublished computer-based figure choice scale, the Body Manipulation Scale (Evans & Tovée, 2012).

3.4.2.1 Rationale.

This scale was developed in response to a number of concerns about the CBIS and similar figure-choice scales used to measure girls’ evaluative body dissatisfaction. Such scales (e.g., Collins, 1991) typically feature fewer than ten figures from which participants can choose, resulting in relatively coarse gradations of measurement. The figures are usually presented as a complete array, arranged in order of increasing size, potentially encouraging regression to the mean. Finally, figures tend to be line drawings, poorly defined and distributed arbitrarily across the distribution of adiposity. Whilst Truby and Paxton’s (2002)

scale has the advantage of photographic images of children within a known BMI range, it fails to sample equally across the full spectrum of adiposity (see Table 3.1).

This scale, therefore, was designed to provide several advantages over similar instruments. In keeping with recent recommendations, it provided a greater number of figures than pre-existing alternatives–thus minimising scale coarseness–and the adipose variation of its array of figures was based upon the full distribution of anthropometric data as opposed to an artist’s impression, in order to achieve realism (Gardner & Brown, 2010). It assessed evaluative body dissatisfaction in a similar manner to the CBIS but without the use of a continuously-present ordered visual array, presenting only one figure at a time which appeared to ‘morph’ into the next.

3.4.2.2 Scale development.

As with the CBIS, participants were required to select a figure that they considered most resembled their own (self) and one they most wished to resemble (ideal). The figures were created by Dr Martin Toveé, a specialist in the creation of life-like, anthropometrically accurate 3D human images. Each figure depicted a young photorealistic female, generated in Daz Studio 3.1 Version 9 (http://www.daz3d.com) to reflect the proportions of a Caucasian nine and a half year old girl (Victoria 4.2 Model) using the “youth” scale on the Morphs++ package. The body shape of this figure was then altered to create a continuum of body shapes simulating 12 different adipose levels, which were then rendered and exported as 24- bit colour BMP image files (567 x 846 pixels) for use as stimuli. The face-on figures shared the same facial ‘identity’ and wore identical one-piece swimsuits. As previously stated, only one version of the figure was shown on the computer screen at any one time.

The body volume of each figure was measured by exporting each 3D body model into Autodesk 3ds Max Version 8 (http://www.usa.autodesk.com) as a wavefront object, assuming the body had a height of 1.4m (average height of the participants in this study). Weight was then estimated, assuming that the bodies had an average density of 1.1g/cm3 (Durnin & Taylor, 1960): from this BMI could then be calculated. The figures corresponded consecutively to BMIs on the 2nd, 5th, 10th, 20th, 35th, 50th, 65th, 75th, 85th, 90th, 93rd and >95th percentiles of the CDC reference (Ogden, et al., 2002) for girls aged 9.5 years. The figures ranged in apparent body mass index from 13.4 to 22.6 in 12 intervals. Table 3.1 displays the BMIs and centiles represented by the BMS images alongside those represented by the images on the CBIS for ease of comparison.

Table 3.1 Body manipulation scale (BMS) and Children’s Body Image Scale (CBIS) stimulus images compared on simulated body mass index (BMI)

BMS Simulated BMI (assuming height 1.4m and age 9.5 years) BMS Figure: CDC 2000a percentile BMS Figure: WHO 2007b growth standards Equivalent CBIS image CBIS Figure: CDC 2000a percentiles CBIS Figure: WHO 2007b growth standards 1 13.4 2nd 3rd A 13.0–13.5 1st – 2nd 1st – 3rd 2 13.9 5th 6th B 13.6–14.9 2nd – 18th 4th – 20th 3 14.2 8th 9.5th 4 15.0 20th 22nd C 15.0–16.6 19th – 50th 21st – 54th 5 15.8 34th 38th 6 16.7 51st 56th D 16.7–17.7 51st – 68th 55th – 73rd 7 17.5 66th 71st 8 18.5 76th 82nd E 17.8–19.4 69th – 84th 74th – 89th 9 19.4 84th 90th 10 20.4 91st 94th F 19.5–24.6 85th – 97th 11 21.5 93rd 97th 90th – 99.4th 12 22.6 95th >98th - - - G 24.7 – 28.5 > 97th > 99.7th

Note. a Center for Disease Control (2000) centiles; b World Health Organisation (2007) centiles

3.4.2.3 Procedure of use.

Participants were seated, one-by-one, next to the experimenter. In front of them was a desk, a laptop and an external mouse. The laptop computer screen showed the first computer-generated figure in the sequence. Participants were asked to adjust the dimensions of the figure by moving the mouse left or right: one direction increased the apparent adiposity of the figure, whilst the other decreased it. Participants were asked to identify both their preferred figure (ideal) and their perceived figure (self) in this way. Instructions were displayed on screen, and were also read aloud to the participant. By pressing the mouse button, the participants saved their response once the figure displayed on screen depicted their chosen size of figure. Both the left/right directionality of the size change and the order

in which the questions were asked were randomised. Figure 3.2 illustrates some of the stimulus images used; the full range of images is presented in Appendix K. Participants completed a practice trial to familiarise themselves with the paradigm before undertaking the task.

Figure 3.2 Body manipulation scale stimulus images consisting of figures of simulated body mass index 13.4 kg/m2, 16.7 kg/m2 and 22.6 kg/m2 respectively

The computer program recorded data about the exact lateral position of the cursor on the screen when the participant ‘clicked’ to endorse a figure. Cursor position ranged from – 50 frames to + 50 frames and changes in cursor position give rise to changes in the adiposity of the figure displayed. As such this represented a sensitive interval-level figure choice measure which, nevertheless, permitted the simulated BMI of the figure chosen to be specified. The discrepancy between the two recorded positions was used to indicate the direction and extent of body dissatisfaction: a negative difference indicated a smaller ideal body than perceived.

3.4.2.4 Validation of the BMS.

The BMS was validated with a separate sample of 51 girls aged between 8 and 12 years old (mean age = 10.3 years; SD = 0.7) recruited from schools that participated in the cross-sectional study, two years after that study was completed. Participants completed the BMS, the CBIS and the body esteem scale (BES; Mendelson, White, & Mendelson, 1996) on two occasions, 14 days apart. During each testing session, the BMS was administered twice – once at the beginning of the session and once at the end – to derive internal consistency

values. A mean of the two figures identified per session as ‘self’ was calculated, and a mean of the two figures identified per session as ‘ideal’ was also calculated. These values were used in calculating test-retest reliability.

Good internal consistency values for ideal (α = .80) and perceived (α = .92) figure were obtained (Evans & Tovée, 2012). Two week test-retest reliability values for ideal (r = .68) and perceived (r = .67) figure were found to be adequate. These test-retest data are comparable to those obtained with populations of a similar age (Collins, 1991; Truby & Paxton, 2008). The body dissatisfaction scores showed good convergent validity with those derived from the CBIS (r = .69) and from the weight satisfaction subscale (r = .60) of the BES (Truby & Paxton, 2002).