Table 1.

Characteristics of participants overall and by age group

	Overall (n=2691)		20–39 year (n=1528)		40–59 year (n=1163)		P value*
Sex, n, %
Men	2099	78.0	1123	73.5	976	83.9	<0.001
Women	592	22.0	405	26.5	187	16.1
Age, mean, SD, year	38.4	8.0	32.6	4.6	46.0	4.4	<0.001
Type of occupation, n, %
Clerical	899	33.4	698	33.3	201	34.0	0.186
Sales	494	18.4	403	19.2	92	15.5
Research	322	12.0	243	11.6	79	13.3
Manufacturing	975	36.2	755	36.0	220	37.2
Total Medical expenditures,† mean, SD	73 030	261 743	63 823	286 212	85 126	225 149	<0.001
Dental check-ups,‡ n, %	2586	96.1	1488	97.4	1098	94.4	<0.001
Dental check-ups, mean, SD, times	9.9	3.8	10.2	3.6	9.4	4.1	<0.001
Dental check-up fees, mean, SD, JPY	26 139	10 142	26 997	9487	25 011	10 844	<0.001
Decayed teeth,§ mean, SD	0.54	1.30	0.52	1.24	0.55	1.37	0.743
Missing teeth,§ mean, SD	3.52	2.61	2.92	2.01	4.33	3.08	<0.001
CPI, n, %
Code 0 (healthy)	260	10.1	169	11.4	91	8.3	<0.001
Code 1 (bleeding)	20	0.8	17	1.1	3	0.3
Code 2 (calculus)	1578	61.0	1004	67.5	574	52.3
Code 3 (shallow pocket)	465	18.0	218	14.7	247	22.5
Code 4 (deep pocket)	263	10.2	80	5.4	183	16.7

¥100≈US$1.

*Using the χ2 test and Student's t-test or Mann-Whitney test.

†Included in dental and general (outpatient and inpatient) medical expenditures in 2002 (baseline).

‡Attended at least one of the 13 dental check-ups between 2002 and 2014.

§Participants who did not attend any dental check-ups between 2002 and 2014 were excluded.

CPI, Community Periodontal Index.