Table 1.
Participant characteristics.
| Characteristic | All Participants | With Diagnosis 1 | Without Diagnosis 2 | p-Value 5 | |||
|---|---|---|---|---|---|---|---|
| Mean ± SD or N (%) | N | Mean ± SD or N (%) | N | Mean ± SD or N (%) | N | ||
| Age (years) | 14.10 ± 0.49 | 266 | 14.26 ± 0.51 | 69 | 14.05 ± 0.47 | 196 | 0.002 |
| Male/Female | 127/139 (47.7/52.3%) | 266 | 36/33 (52.2/47.8%) | 69 | 93/103 (47.5/52.5%) | 196 | 0.499 |
| Smoking no/yes 3 | 239/26 (90.2/9.8%) | 265 | 59/10 (85.5/14.5%) | 69 | 179/16 (91.8/8.2%) | 195 | 0.132 |
| Body Mass Index (BMI) | 19.92 ± 3.00 | 248 | 20.34 ± 3.61 | 65 | 19.77 ± 2.74 | 183 | 0.187 |
| Alcohol units per week 4 | 0.46 ± 1.77 | 266 | 0.69 ± 2.85 | 69 | 0.39 ± 1.19 | 196 | 0.218 |
| Level of Parental Education (LPE) | 5.07 ± 1.52 | 248 | 5.21 ± 1.40 | 66 | 5.02 ± 1.56 | 182 | 0.371 |
1 Diagnosis was defined as a diagnosis possible to influence learning; this was indicated by students themselves and included (but not limited to) dyslexia, dyscalculia, depression, autism, and Attention Deficit Hyperactivity Disorder (ADHD); 2 without diagnosis was defined as all students who did not indicate to have a diagnosis; 3 smoking was defined as anybody who indicated to smoke more than 0 cigarettes per week; 4 alcohol units per week was operationalized as number of day per week that alcohol is consumed times units per consumption moment; 5 comparison between those with and those without diagnoses. ANOVA was used for age, BMI, LPE and alcohol units per week, Chi Square for smoking, and sex. Significant differences (p < 0.05) are noted in bold.