Table 3

Associations between age and seasonality the incidence of malaria and non-malaria fever.

Incidence of malaria

Category

Group

Episodes

Person years

Incidence

IRR* (95% CI)

p-value

Age

4-5 years

358

394

0.91

1.0 (reference)

-

6-7 years

303

418

0.72

0.85 (0.66-1.10)

0.22

8-10 years

264

454

0.58

0.64 (0.50-0.84)

0.001

Season

Mar-Apr + Jul-Dec

439

856

0.51

1.0 (reference)

-

Jan-Feb + May-Jun

486

411

1.18

2.52

< 0.001

Non-malaria fever

Age

4-5 years

857

394

2.18

1.0 (reference)

-

6-7 years

693

418

1.66

0.75 (0.64-0.87)

< 0.001

8-10 years

683

454

1.5

0.66 (0.57-0.77)

< 0.001

Season

Rest of the year

1682

1048

1.61

1.0 (reference)

-

May-Jun

551

219

2.52

1.57 (1.40-1.77)

< 0.001

*Incidence rate ratio estimated using a negative binomial regression model

Jensen et al. Malaria Journal 2009 8:213   doi:10.1186/1475-2875-8-213