Table 4.
Prevalence and adjusted odds ratios of false-negative reporters about smoking status according to characteristics in current smokers a.
| Characteristic | False-Negative Reporters | Crude OR | 95% CI | Adjusted OR b | 95% CI | ||
|---|---|---|---|---|---|---|---|
| Cases/Subjects | Prevalence (%) | ||||||
| Sex | Boys | 32/97 | 33.0 | Referent | Referent | ||
| Girls | 13/23 | 56.5 | 2.64 | 1.05, 6.67 | 2.27 | 0.70, 7.40 | |
| Grade | 12th | 17/33 | 43.6 | Referent | Referent | ||
| 11th | 9/47 | 19.2 | 0.31 | 0.12, 0.80 | 0.44 | 0.13, 1.56 | |
| 10th | 19/34 | 55.9 | 1.64 | 0.65, 4.14 | 1.66 | 0.49, 5.60 | |
| Perceived threat to confidentiality | No | 19/58 | 32.8 | Referent | Referent | ||
| Yes | 26/62 | 41.9 | 1.48 | 0.70, 3.12 | 1.48 | 0.56, 3.94 | |
| Closest friend smoking | Most/All | 11/59 | 18.6 | Referent | Referent | ||
| Some | 18/44 | 40.9 | 3.02 | 1.24, 7.35 | 1.58 | 0.53–4.71 | |
| No | 16/17 | 94.1 | 69.80 | 8.35, 583.661 | 58.21 | 6.37, 531.76 | |
| Urine cotinine c | 3rd tertile | 11/40 | 27.5 | Referent | Referent | ||
| 2nd tertile | 10/40 | 25.0 | 0.88 | 0.32, 2.38 | 1.12 | 0.31, 4.02 | |
| 1st tertile | 24/40 | 60.0 | 3.96 | 1.55, 10.11 | 3.96 | 1.11, 14.13 | |
Abbreviation: CI, confidence interval; OR, odds ratio. a Current smokers based on the combined method (either self-reported questionnaire and/or urinary cotinine test, gold standard). b Adjusted for all covariates. c Cutoff points of first tertile and second tertile were 131.1 ng/mL and 695.0 ng/mL.