Remotely-sensed, nocturnal, dew point correlates with malaria transmission in Southern Province, Zambia: a time-series study

Table 4 Zonal ARIMAX models’ variables, parameters and forecasts

Model and parameters ( *p,d,q*)	AIC-fit	MAE-test
High-ARIMAX( 6,1,5)	13.34	6.4%
Medium-ARIMAX (4,0,3)	80.61	16.2%
Low-ARIMAX (4,0,4)	137.44	28.6%
High zone variables	Coefficient	p-value
L7 DWP	0.033	p < 0.01
L7 LST	0.14	p < 0.001
L5 NDVI	0.83	p = 0.19
L7 NDVI	1.38	p < 0.01
Medium zone variables	Coefficient	p-value
L5 DWP	0.076	p < 0.001
L8 NDVI	3.51	p < 0.001
Low zone variables	Coefficient	p-value
L3 LST	0.024	p = 0.348
L8 NDVI	3.79	p < 0.001
L5 DWP	0.073	p < 0.001
Forecast w37-41 2013	MAE	Predicted *vs.* actual incidence
HIGH-ARIMAX	-29.40%	63.0 vs. 89.9
MEDIUM-ARIMAX	40.27%	3.77 vs. 3.48
LOW-ARIMAX*	-29.59%	0.91 vs. 1.48

Akaike’s information criteria (AIC) and mean average prediction error (MAE) are shown for the best-fit models of the high-, medium- and low-transmission zone ARIMAX models. MAE is calculated for the testing period of the models, i e, 2011 w19 through 2012 w18. Normalized differentiated vegetation index (NDVI), nocturnal land-surface temperature (LST) and nocturnal dew point (DWP) are shown with specific lag-times with its coefficients as well as p-values. Four-week forecasts MAE and predicted cases vs. actual cases for the four weekly forecasts of the zonal models are shown.
*ARIMAX LOW forecast only three weeks ahead, due to using LST lagged at three weeks.

ISSN: 1475-2875