Table 4. Adjusted Poisson regression for premenstrual syndrome in relation to sociodemographic, behavioral, reproductive, and health variables of students at a university in Midwest Brazil, 2018 ( n = 1,115) .
| Level | Variables | PR (95% CI) | p -value |
|---|---|---|---|
| 1 | Course period (semester) | 0.001 a | |
| ≥ 9 th | 1 | ||
| 7 th and 8 th | 1.19 (0.93–1.52) | ||
| 5 th and 6 th | 1.17 (0.92–1.49) | ||
| 3 rd and 4 th | 1.30 (1.03–1.63) | ||
| 1 st and 2 nd | 1.44 (1.14–1.80) | ||
| 2 | Eating habits * | 0.058 b | |
| Unhealthy | 1 | ||
| Healthy | 0.88 (0.76–1.00) | ||
| Alcohol consumption (last 30 days) | 0.018 b | ||
| No | 1 | ||
| Yes | 1.23 (1.04–1.47) | ||
| Use of hormonal contraceptives | 0.115 a | ||
| No | |||
| 1 | 0.94 (0.80–1.10) | ||
| 2 or + | 1.22 (1.02–1.46) | ||
| Menarche | 0.094 b | ||
| ≥ 12 years | 1 | ||
| < 12 years | 1.13 (0.98–1.30) | ||
| 3 | Depression ** | < 0.001 b | |
| No | 1 | ||
| Yes | 1.49 (1.30–1.71) |
Abbreviations: 95% CI: 95% confidence interval; PR, prevalence ratio.
Each variable was adjusted to the others at the same or previous level in a hierarchical model of causality. Only variables associated with the outcome at p < 0.20 in the unadjusted model were subsequently entered and retained in the final multivariate-adjusted model.
*
Healthy eating habits considered: consumption of fruits and vegetables ≥ 5 days/week.
**
Diagnosed by a doctor, as reported by the student.
a
Wald test, p -value for linear trend.
b
Wald test, p -value for heterogeneity.