Does anthropometric status at 6 months predict the over-dispersion of malaria infections in children aged 6–18 months? A prospective cohort study

Table 2 Association of length-for-age, weight-for-length, and weight-for-age z-scores at age 6 months with malaria incidence from age 6 months to 18 months

	Incidence of ‘presumed’ malaria (N = 2561)				Incidence of clinical malaria (N = 2497)				Incidence of confirmed malaria (N = 2497)
	Unadjusted		Adjusted^a		Unadjusted		Adjusted^a		Unadjusted		Adjusted^a
	IRR^b (95% CI)	p-value	IRR^b (95% CI)	p-value	IRR^b (95% CI)	p-value	IRR^b (95% CI)	p-value	IRR^b (95% CI)	p-value	IRR^b (95% CI)	p-value
Predictor at age 6 months
LAZ	0.98 (0.94 to 1.02)	0.370	1.03 (0.98 to 1.09)	0.394	0.91 (0.85 to 0.98)	0.011	0.98 (0.89 to 1.07)	0.703	0.92 (0.87 to 0.97)	0.003	1.00 (0.94 to 1.07)	0.882
WLZ	0.96 (0.92 to 1.01)	0.098	0.97 (0.92 to 1.02)	0.190	0.99 (0.95 to 1.04)	0.762	1.03 (0.94 to 1.12)	0.571	0.99 (0.94 to 1.04)	0.623	1.00 (0.94 to 1.06)	0.950
WAZ	0.97 (0.93 to 1.01)	0.094	1.10 (0.50 to 2.42)	0.810	0.95 (0.88 to 1.01)	0.093	1.07 (0.29 to 3.91)	0.916	0.95 (0.90 to 0.99)	0.030	1.46 (0.48 to 4.40)	0.506

CI: confidence interval; IRR: incidence rate ratio; LAZ: length-for-age z-score; WAZ: weight-for-age z-score; WLZ: weight-for-length z-score
^aAdjusted for the following factors at age 6 months: sex of the child, haemoglobin concentration, iron status, month of birth, daily use of insecticide-treated bed nets, distance to health facility, study site, asset scores, maternal age, maternal education, children < 5 years, HFIA score, and whether the child received the study intervention (LNS) or not
^bIncidence rate ratio, obtained using negative binomial regression. The IRR represents the rate of change in incidence of malaria for each 1-SD higher LAZ, WAZ, or WLZ

ISSN: 1475-2875