Table 2.
Univariate negative binomial regression (NBR) models for the DF incidence rates by month with incidence rate ratio (IRR) and 95% confidence interval (CI)
| Month | Hanoi | Khanh Hoa | Ho Chi Minh City | An Giang |
|---|---|---|---|---|
| January | 2.73 (1.19-6.26)* | 1.26 (0.73-2.18) | 1.61 (1.03-2.53)* | 2.12 (1.39-3.22)*† |
| February | Reference: 1 | Reference: 1 | Reference: 1 | Reference: 1 |
| March | 1.36 (0.59-3.14) | 0.90 (0.52-1.56) | 0.84 (0.54-1.32) | 1.04 (0.68-1.59) |
| April | 1.43 (0.62-3.30) | 1.12 (0.65-1.92) | 0.71 (0.45-1.11) | 1.69 (1.11-2.56)* |
| May | 5.14 (2.24-11.77)*† | 1.34 (0.78-2.30)* | 0.71 (0.45-0.11) | 2.58 (1.70-3.92)*† |
| June | 6.63 (2.90-15.19)*† | 1.79 (1.04-3.09)* | 0.99 (0.63-1.54) | 3.28 (2.16-4.98)*† |
| July | 14.94 (6.52-34.17)*† | 2.55 (1.43-4.39)*† | 1.40 (0.89-2.19) | 3.58 (2.36-5.45)*† |
| August | 22.02 (9.63-50.34)*† | 2.46 (1.43-4.24)*† | 2.06 (1.31-3.22)*† | 4.57 (3.01-6.94)*† |
| September | 38.47 (16.83-87.94)*† | 2.35 (1.36-4.04)*† | 1.91 (1.22-2.99)* | 5.26 (3.46-8.00)*† |
| October | 55.07 (23.65-123.59)*† | 2.69 (1.56-4.63)*† | 2.40 (1.53-3.76)*† | 4.49 (2.95-6.83)*† |
| November | 46.69 (20.43-106.73)*† | 2.22 (1.29-3.83)*† | 2.35 (1.50-3.67)*† | 3.49 (2.30-5.31)*† |
| December | 13.44 (5.88-30.74)*† | 1.75 (1.02-3.01)* | 1.84 (1.18-2.89)*† | 3.01 (1.98-4.58)*† |
* = statistically significant (P < 0.05)
† = Bonferroni adjustment (P < 0.05/11)