Table 1.
Comparison of Characteristics at Age 18 Years for Those Included and Not Included
| Characteristic at Age 18 Years | No. (%) | P Value | |
|---|---|---|---|
| Included | Not Included | ||
| Total | 903 (87.1) | 134 (12.9)a | |
| Men | 461 (51.1) | 74 (55.2) | .37 |
| Low socioeconomic statusb | 175 (19.5) | 40 (30.1) | .005 |
| Smoked cannabis at least weekly | 75 (8.3) | 6 (4.5) | .12 |
| Tobacco use, mean (SD), pack-years | 0.65 (1.13) | 0.95 (1.42) | .06 |
a
Twenty-two participants had died by the assessment at age 32 years; of the remaining 112, 57 were assessed at age 32 years but did not provide dental or periodontal data, and 12 more provided dental data but not cannabis data.
b
Socioeconomic status was measured by categorizing adult occupation using standard New Zealand occupation-based indices, which employ a 6-interval classification; those with a score of 5 or 6 were categorized as having low socioeconomic status.