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Table 2 Incidence rate and hazard ratios for Plasmodium vivax episodes according to exposure status

From: Declining malaria transmission in rural Amazon: changing epidemiology and challenges to achieve elimination

  N episodes Person-years of follow-up Rate (episodes/100-PY) (95 % CI) Univariable IRR (95 % CI) P value Multivariable IRR (95 % CI) P value
Gender
Female 279 802 34.8 (31.0–39.1) 1 0.151 1 0.204
Male 377 998 37.8 (34.2–41.8) 1.2 (0.9–1.5) 1.2 (0.9–1.5)
Age (years)
0–10 194 451 43.0 (37.3–49.5) 1   1  
10–20 143 436 32.8 (27.8–38.6) 0.7 (0.6–1.0) 0.059 0.7 (0.5–0.9) 0.038
20–40 163 429 38.0 (32.6–44.3) 0.9 (0.7–1.3) 0.709 1.0 (0.7–1.3) 0.954
40–60 114 328 34.7 (28.9–41.7) 0.9 (0.6–1.2) 0.461 0.9 (0.6–1.3) 0.524
≥60 42 153 27.3 (20.2–36.9) 0.7 (0.5–1.2) 0.195 0.8 (0.5–1.2) 0.229
Socio-economic status
Lowest quintile 258 702 36.7 (32.5–41.5) 1.0 (0.8–1.2) 0.798 0.9 (0.7–1.1) 0.422
2nd–4th quintiles 284 707 40.2 (35.8–45.1) 1   1
Highest quintile 114 320 35.6 (29.6–42.7) 1.0 (0.7–1.3) 0.825 0.9 (0.7–1.2)
Season
Rainy 238 750 31.7 (27.9–36.0) 1 0.007 1 <0.001
Dry 418 1049 39.9 (36.2–43.9) 1.2 (1.1–1.5) 1.4 (1.1–1.6)
Use of ITN
No 362 857 42.3 (38.1–46.8) 1 0.199 1 0.001
Yes 294 943 31.1 (27.8–35.0) 0.9 (0.7–1.1) 0.7 (0.6–0.8)
IRS in last 6 months
No 149 530 28.1 (23.9–33.0) 1 0.015 1 0.002
Yes 507 1200 42.3 (38.7–46.1) 1.4 (1.1–1.8) 1.4 (1.1–1.8)