FAS III used in the Czech Republic consists of 6 items based on joint assessment and validation from the HBSC FAS development project [17]. The questions include new and refined items from previous FAS versions: Bedrooms (FAS II), Computers (FAS II), Cars (FAS II), Holidays abroad (refined), Dishwasher (new), Bathroom (new), as defined by the HBSC 2013–2014 Protocol. The items and their response categories are as follows:

• Does your family own a car or another motorized vehicle? (No = 0; Yes, one = 1; Yes, two = 2).
• Do you have your own bedroom? (No = 0; Yes = 1).
• How many computers (including laptops and tablets, not including game consoles and smartphones) does your family own? (None = 0, One = 1; Two = 2; More than two = 3).
• How many bathrooms (room with a bath/shower or both) are there in your home? (None = 0; One = 1; Two = 2; More than two =3）
• Does your family have a dishwasher? (No = 0; Yes = 1).
• How many times did you and your family travel out of the Czech Republic for holiday/vacation last year? (Never = 0; Once = 1; Twice = 2; More than twice = 3).

FAS III consists of 6 items. The responses to the items are given as specific values and calculated as an aggregated FAS index ranging from 0 to 13.

The Family Affluence Scale as an Indicator for Socioeconomic Status: Validation on Regional Income Differences in the Czech Republic
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750958/

The FA scale was developed within the HBSC research network as a measure of parental SES [53]. The FA scale, including easily answerable questions that reflect material affluence, has proved to be a useful indicator of family material affluence [53].

Between 2002 to 2010, four items were included to determine FA:

•     car ownership (No=0, One=1, Two or more=2),
•     number of computers (None=0, One=1, Two=?2, Three or more=3),
•     family holidays in the past year (Never=0, Once=1,Twice=2,Three or more times=3), and
•     having one’s own bedroom (No=?0; Yes?=?1) [53].

In 2014, the FA scale was updated with respect to the changes in the social environment [44, 54]. Two new FA-related items –

•     dishwasher ownership (No=0,Yes=1) and
•     number of bathrooms (None=0,One=1; Two=2,Three or more=3)

were added to the existing FA scale.

The response codes to these items were summed and treated as a composite sum score. For the trend analyses, three categories of FA (“low”, “medium”, and “high”) were derived from the composite sum score.

Between 2002 and 2010 the FA categories correspond to tertiles of the sum score (low=0–3, medium=4–6, high=7–9) and in 2014 as follows: low=0–6, medium=7–9, and high=10–13 [14].

14 Family Affluence and the Eating Habits of 11- To 15-Year-Old Czech Adolescents: HBSC 2002 and 2014
https://pubmed.ncbi.nlm.nih.gov/27783063/

The FA scale provides a valid assessment of household material affluence among families with adolescents [53] with documented high validity (kappa coefficients 0.41%–0.74%, 76.2%–88.1% agreement) and moderate reliability (Cronbach’s α?=?0.58) between children’s and parents’ responses on the FA scale-related items [55–58].

Trends and correlates of overweight/obesity in Czech adolescents in relation to family socioeconomic status over a 12-year study period (2002–2014)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5764007/