Table 2.

Characteristics of the study sample by dentine caries experience (DMFT)

Variables	N (%)	DMFT median (IQR)	DMFT mean (SD)
Total	6351	1 (0–4)	2.50 (3.29)
Sex
Female	3249 (51.2)	1 (0–4)	2.60 (3.37)
Male	3102 (48.8)	1 (0–4)	2.39 (3.19)
Age, mean (SD)	15.51 (1.46)
13–15 years	3629 (57.1)	1 (0–3)	1.88 (2.66)
16–17 years	2722 (42.9)	2 (0–5)	3.31 (3.82)
Nordic birth country parents
Both parents	5590 (88.0)	1 (0–4)	2.48 (3.28)
One parenta	331 (5.2)	1 (0–3)	2.31 (3.03)
None of the parentsb	401 (6.3)	2 (0–4)	2.95 (3.57)
Unknown/missing	29 (0.5)	1 (0–5)	2.48 (3.08)
Family economy
Better/same financial situation as most others	5813 (91.5)	1 (0–4)	2.46 (3.27)
Worse financial situation	463 (7.3)	2 (0–4)	2.86 (3.45)
Unknown/missing	75 (1.2)	2 (0–6)	3.28 (3.54)
Parental employment
Both parents in paid work	4636 (73.0)	1 (0–3)	2.26 (3.07)
One parent in paid workc	1205 (19.0)	2 (0–4)	2.87 (3.64)
None of the parents in paid workd	198 (3.1)	3 (0–6)	3.88 (4.08)
Unknown/missing	312 (4.9)	2 (0–6)	3.60 (3.84)
Living arrangements
Both parents	3880 (61.1)	1 (0–3)	2.20 (3.09)
Both parents, but shared	1110 (17.5)	2 (0–4)	2.56 (3.26)
One of the parents	804 (12.7)	2 (0–5)	3.16 (3.56)
Not living with parents	260 (4.1)	2 (0–5)	3.30 (3.86)
Unknown/missing	297 (4.7)	2 (0–6)	3.60 (3.88)
Toothbrushing frequency
Daily	5910 (93.1)	1 (0–4)	2.39 (3.16)
Non-daily	406 (6.4)	3 (1–6)	4.18 (4.48)
Missing	35 (0.6)	0 (0–1)	1.11 (1.92)

N: Number of participants; DMFT: Decayed, Missing, and Filled Teeth; IQR: Interquartile range; SD: Standard deviation

^aIncluded 56 participants with a missing answer for one of the parents

^bIncluded 31 participants with a missing answer for one of the parents

^cIncluded 141 participants with a missing answer for one of the parents

^dIncluded 42 participants with a missing answer for one of the parents