Table 2.
Coefficienta Estimates, (Standard Errors), and p-Values from Model for Wave 3 EDI-2 Subscales as a Function of Joint Inattention and Hyperactivity/Impulsivity Classb
| Outcomes: Wave 3 EDI-2 Subscales |
|||
|---|---|---|---|
|
| |||
| Bulimia | Drive For Thinness |
Body Dissatisfaction |
|
|
| |||
| Model adjusted for sex | |||
|
| |||
| ‘Low Symptom’ (≈72% of samplec) | 0.34 (0.10) | −1.30 (0.21) | −1.55 (0.35) |
| -- | -- | -- | |
|
| |||
| ‘Predominantly Inattention’ (≈5% of samplec) | 0.21 (0.17) | −1.42 (0.46) | −1.02 (0.78) |
| p < 0.46 | p < 0.79 | p < 0.49 | |
|
| |||
| ‘Predominantly Hyp/Imp’ (≈1% of samplec) | 0.60 (0.48) | −0.64 (1.90) | −2.78 (1.43) |
| p < 0.59 | p < 0.74 | p < 0.39 | |
|
| |||
| ‘Both Inattention and Hyp/Imp’ (≈22% of samplec) | 0.73 (0.12) | −0.14 (0.31) | 0.43 (0.50) |
| p < 0.01 | p < 0.01 | p < 0.01 | |
|
| |||
| Model adjusted for sex and BMI z-score | |||
|
| |||
| ‘Low Symptom’ (≈72% of samplec) | 0.35 (0.10) | −1.24 (0.21) | −1.48 (0.34) |
| -- | -- | -- | |
|
| |||
| ‘Predominantly Inattention’ (≈5% of samplec) | 0.23 (0.18) | −1.26 (0.46) | −0.83 (0.77) |
| p < 0.48 | p < 0.98 | p < 0.38 | |
|
| |||
| ‘Predominantly Hyp/Imp’ (≈1% of samplec) | 0.63 (0.49) | −0.57 (1.88) | −2.71 (1.37) |
| p < 0.56 | p < 0.72 | p < 0.37 | |
|
| |||
| ‘Both Inattention and Hyp/Imp’ (≈22% of samplec) | 0.73 (0.12) | −0.21 (0.30) | 0.19 (0.47) |
| p < 0.01 | p < 0.01 | p < 0.01 | |
|
| |||
| Model adjusted for sex and YSR anxiety/depression | |||
|
| |||
| ‘Low Symptom’ (≈72% of samplec) | 0.36 (0.09) | −1.22 (0.20) | −1.45 (0.34) |
| -- | -- | -- | |
|
| |||
| ‘Predominantly Inattention’ (≈5% of samplec) | 0.09 (0.17) | −1.81 (0.48) | −1.67 (0.81) |
| p < 0.11 | p < 0.21 | p < 0.79 | |
|
| |||
| ‘Predominantly Hyp/Imp’ (≈1% of samplec) | 0.68 (0.44) | −0.39 (1.65) | −2.40 (1.24) |
| p < 0.47 | p < 0.62 | p < 0.44 | |
|
| |||
| ‘Both Inattention and Hyp/Imp’ (≈22% of samplec) | 0.65 (0.12) | −0.39 (0.30) | 0.01 (0.46) |
| p < 0.01 | p < 0.01 | p < 0.001 | |
Abbreviations: BMI = body mass index; EDI = Eating Disorder Inventory-2; Hyp/Imp = Hyperactivity/Impulsivity; YSR = Youth Self-Report
Coefficients represent the means of the EDI subscales for a particular class, after adjustment for covariates. The table also presents the coefficients’ standard errors (in parentheses), and the p-values from a two-sided test of the hypothesis that the difference between the coefficient for the given class and the referent class (‘Low Symptom’) equals 0. The coefficients come from a model for each EDI-2 subscale as function of covariates (sex, or sex and BMI z-score) and the joint inattention - hyperactivity classes (treated as a 4-level categorical variable, with ‘Low Symptom’ as the reference category).
To determine the classes for inattention (and hyperactivity/impulsivity), we fitted a growth mixture model to the inattention (and hyperactivity/impulsivity) symptoms from Waves 1–3. The model empirically determined two classes characterizing the trajectories of the inattention (and hyperactivity/impulsivity) symptoms across the three time points: a declining trajectory with low levels of symptoms at all time points, referred to as the ‘Low’ class, and a declining trajectory with higher levels of symptoms at all time points, referred to as the ‘High’ class. We created the joint inattention & hyperactivity/impulsivity classes by combining the inattention classes with the hyperactivity/impulsivity classes, such that there were four joint classes (‘Low Symptom’; ‘Predominantly Inattention; ‘Predominantly Hyp/Imp’; and ‘Both Inattention and Hyp/Imp’).
Percentage represents the proportion of the sample most likely to be assigned to the relevant class.