Table 3.

Estimated effect of rainfall and food security on child mortality rates (Model 1)

	Univariate model			Multivariate model
	(n = 156)
	n	IRR (95% CI)	P-value	IRR (95% CI)	P-value
Time in months since January 1997 (t)	156	0.996 (0.994 to 0.997)	<0.001	0.996 (0.995 to 0.998)	<0.001
Sin(2πt/12)	156	1.021 (0.927 to 1.125)	0.670	0.916 (0.835 to 1.001)	0.066
Cos(2πt/12)	156	1.269 (1.158 to 1.390)	<0.001
Rainfall	156	1.470 (1.122 to 1.774)	<0.001	1.364 (1.087 to 1.712)	0.007
Rainfall Lag 1	155	1.093 (0.887 to 1.348)	0.404
Rainfall Lag 2	154	0.921 (0.740 to 1.146)	0.460
Rainfall MA(2)	156	1.363 (1.089 to 1.708)	0.007
Rainfall MA(3)	156	1.244 (0.962 to 1.612)	0.098
Food security	156	0.826 (0.779 to 0.875)	<0.001	0.885 (0.830 to 0.944)	<0.001
Food security Lag 1	155	0.853 (0.804 to 0.904)	<0.001
Food security Lag 2	154	0.891 (0.839 to 0.945)	<0.001
Food security MA(2)	156	0.812 (0.763 to 0.865)	<0.001
Food security MA(3)	156	0.805 (0.753 to 0.861)	<0.001

IRR, incidence rate ratio.

The effect of rain was estimated for every 500-mm increase in mean total monthly rainfall, and the effect of food security for every 500-kg increase in household food security.

Lag(x) refers to the value of the variable lagged by x months; MA(2) refers to the moving average of the variable in the given month and the month before; MA(3) refers to the moving average of the variable in the given month and the previous 2 months.