Table 1 Descriptive characteristics of the study cohort, Liwonde, Malawi April—December 2013

Number of children enrolled

1223

Median age at baseline in months (IQR)

32 (20,45)

Number of children who completed 8 months of follow-up, n (%)

1082 (89)

Total person-years at risk over study period

640

Female, n (%)

598 (49)

Plasmodium infection at baseline by polymerase chain reaction, n/N (%)

300/1222 (25)

Median inverse distance-weighted malaria prevalence < 1 km at baseline (IQR)

24% (14%, 33%)

Median altitude of household, m (IQR)

497 (486, 520)

Anemic at baseline (haemoglobin < 11 g/dl), n/N (%)

546/1212 (45) 

Stunting at baseline, n/N (%)

468/1174 (40)

Wasting at baseline, n/N (%)

180/1217 (15)

Caregiver completed primary school, n/N (%)

258/1217 (21)

ITN used at baseline, n/N (%)

1186/1216 (98)

ITN holes at baseline, n/N (%)

 ≥1 hole of any size

415/1183 (35)

 ≥1 hole between fist and head-sized

168/1175 (14)

 ≥1 hole head-sized or larger

32/1176 (3)

Median number of ITNs within 300 m at baseline^a (IQR)

35 (22,79) 

Total malaria infections over the study period^b

825

Median malaria infections per person-year (IQR)

0 (0, 1.8)