Table 5.
Kappa statistics for test and retest of the SF-FFQ4PolishChildren questionnaire.
| Variables | Cat. 1 | Children Aged 6–10 Years |
Adolescents Aged 11–15 Years |
|
|---|---|---|---|---|
| Parent (Test–Retest) |
Adolescent (Test–Retest) |
Adolescent (Test) & Parent (TestP) |
||
| Sample size | 437 | 630 | 628 | |
| Nutrition knowledge level 2 | 3 | 0.62 | 0.36 | NA |
| Dietary habits | ||||
| Breakfast | 4 | 0.70 | 0.54 | 0.56 |
| Meal at school | 4 | 0.78 | 0.53 | 0.46 |
| Dairy products | 7 | 0.54 | 0.37 | 0.27 |
| Fish | 7 | 0.67 | 0.42 | 0.32 |
| Fast food | 7 | 0.68 | 0.43 | 0.33 |
| Sweetened soft drinks | 7 | 0.56 | 0.39 | 0.28 |
| Fruit or mixed fruit and vegetable juices | 7 | 0.46 | 0.30 | 0.30 |
| Energy drinks | 7 | 0.81 | 0.44 | 0.45 |
| Vegetables | 7 | 0.56 | 0.31 | 0.31 |
| Fruit | 7 | 0.53 | 0.31 | 0.27 |
| Sweets | 7 | 0.59 | 0.36 | 0.27 |
| pHDI | 3 | 0.55 | 0.44 | 0.31 |
| nHDI | 3 | 0.45 | 0.35 | 0.26 |
| Active/sedentary lifestyle | ||||
| Screen time | 6 | 0.72 | 0.46 | 0.35 |
| Physical activity level | 3 | 0.68 | 0.52 | 0.36 |
| Physical activity at school | 3 | 0.69 | 0.54 | 0.40 |
| Physical activity at leisure time | 3 | 0.69 | 0.51 | 0.31 |
| FAS components | ||||
| How many computers, laptops, or tablets does your family own? | 4 | 0.79 | 0.69 | 0.55 |
| Does your family own a car, van, or truck? | 3 | 0.84 | 0.76 | 0.70 |
| Does your family have a dishwasher? | 2 | 0.93 | 0.89 | 0.87 |
| Do you have your own bedroom? | 2 | 0.90 | 0.83 | 0.74 |
| How many bathrooms (room with a bath or shower) are in your home? | 4 | 0.88 | 0.84 | 0.79 |
| Does your home have an outdoor space attached (e.g., garden)? | 2 | 0.85 | 0.85 | 0.84 |
| BMI-for-age | 3 | 0.67 | 0.64 | 0.65 |
1 Cat.—number of categories in the question; nutrition knowledge level—based on 18 questions and assessed in three categories: Low (0–5 points), moderate (6–12 points), high (13–18 points) [22]; 2 in a group of 6–10-year-old children, nutrition knowledge was assessed in their parents; pHDI—a pro-healthy diet index composed of four questions (dairy products, fish, vegetables, fruit) and assessed in three categories: Low (0–33.32% points), moderate (33.33–66.65% points), high (66.66–100% points) [22]; nHDI—a non-healthy diet index composed of four questions (fast food, sweetened soft drinks, energy drinks, sweets) and assessed in three categories: Low (0–33.32% points), moderate (33.33–66.65% points), high (66.66–100% points) [22]; physical activity level—based on two questions: Physical activity at school and physical activity at leisure time, and assessed in three categories: Low (0–1 points), moderate (2–4 points), high (5 points) [22]; FAS components—six questions of the Family Affluence Scale [26]; BMI-for-age—the age-sex-specific body mass index calculated using self-reported height and weight and assessed in three categories [27]; NA—not applied.