Associations between flavour preferences, harm perceptions and use of flavoured WPT during preconception and pregnancy (N=58)
| Predictor | Menthol/Mint* | Fruit† | ||
| IRR (95% CI) | P value | IRR (95% CI) | P value | |
| Age | 0.98 (0.90 to 1.07) | 0.723 | 1.08 (0.97 to 1.20) | 0.152 |
| Latina ethnicity‡ | 4.01 (1.88 to 8.54) | <0.001 | 0.74 (0.28 to 1.97) | 0.546 |
| Flavour preferences | 1.77 (1.39 to 2.25) | <0.001 | 1.96 (1.20 to 3.19) | 0.007 |
| Flavour perceptions | ||||
| General harm | 0.90 (0.67 to 1.22) | 0.505 | 1.17 (0.85 to 1.62) | 0.346 |
| Fetal harm | 0.95 (0.73 to 1.26) | 0.740 | 0.83 (0.58 to 1.19) | 0.312 |
| Dual/poly WPT use§ | 0.25 (0.12 to 0.52) | <0.001 | 1.09 (0.40 to 2.93) | 0.872 |
Negative binomial regression with robust variance estimation was used for all count variables (menthol/mint and fruit-flavoured WPT events over preconception and first trimester). Age, preferences and perceptions (general harm, fetus) are continuous variables; ethnicity (1=Latina; 0=non-Latina) and use status (1=dual/poly WPT user; 0=WPT only user) were dummy coded.
Bold font indicates statistically significant IRRs.
*Overdispersion parameter: α=1.84 (95% CI 1.27 to 2.66).
†Overdispersion parameter: α=2.70 (95% CI 1.57 to 4.64).
‡Reference category is non-Latina (0).
§Reference category is WPT-only users (0).
IRR, incidence rate ratio; WPT, waterpipe tobacco.