Table 2.

Patient characteristics

Patient characteristics	na (total =267)	%
Age, years
<30	4	1
30–40	26	10
41–50	48	18
51–60	107	40
61–70	44	16
71–80	26	10
>80	4	1
Gender
Female	155	58
Male	104	42
Education
No degree	0	0
Lower secondary education	32	12
College	17	6
Vocational education	73	27
Academic or comparable degree	135	51
Smoking status
Current smoker	62	23
Former smoker	107	40
Non-smoker (never smoked)	63	24
Time since diagnosis of periodontal disease, years
<1	36	13
1–2	34	13
≥3	182	68
Treatment experience
Treated	214	80
Not treated; treatment planned	33	12
Not treated; patient cannot/refuses to be treated	6	2
Health insurance
Statutory health insurance without supplementary dental insurance	125	47
Statutory health insurance with supplementary dental insurance	70	26
Privately insured	63	24

Note:

^aNumber of patients within group (if numbers do equal 267, data are missing).