Table 4 Adjusted negative binomial regression predicting the outcome of confirmed malaria cases and using the estimated health facility catchment area population as the offset.

From: Leveraging risk maps of malaria vector abundance to guide control efforts reduces malaria incidence in Eastern Province, Zambia

FactorCategorizationIRR (95% CI)p-value
Trial armGeographically-concentratedReferenceReference
 Health facility-targeted1.350 (1.212–1.504)<0.001
 Ecologically-targeted0.867 (0.788–0.954)0.004
Time periodPre-2017 IRS operationsReferenceReference
 Post-2017 IRS operations0.680 (0.599–0.772)<0.001
Trial arm by time period interactionGeographically-concentrated by Post-2017 IRS operationsReferenceReference
 Health facility-targeted by Post-2017 IRS operations1.396 (1.235–1.578)<0.001
 Ecologically-targeted by post-2017 IRS operations0.873 (0.793–0.962)0.006
Type of health facilityHealth centerReferenceReference
 Hospital2.536 (1.836–3.503)<0.001
 Health post2.100 (1.956–2.255)<0.001
NDVI lagged 1 monthQuintile 1 (0.148–0.205)ReferenceReference
 Quintile 2 (0.205–0.275)1.166 (1.089–1.248)<0.001
 Quintile 3 (0.278–0.343)2.055 (1.923–2.190)<0.001
 Quintile 4 (0.362–0.430)2.671 (2.515–2.837)<0.001
 Quintile 5 (0.435–0.487)2.759 (2.593–2.936)<0.001
Precipitation lagged 1 monthQuintile 1 (0.0 mm–0.9 mm)ReferenceReference
 Quintile 2 (0.9 mm–7.0 mm)1.037 (0.978–1.098)0.222
 Quintile 3 (7.0 mm–75.8 mm)1.214 (1.147–1.284)<0.001
 Quintile 4 (76.0 mm–183.2 mm)1.262 (1.193–1.336)<0.001
 Quintile 5 (183.2 mm–402.2 mm)1.264 (1.189–1.344)<0.001
AltitudeQuintile 1 (438 m–774 m)ReferenceReference
 Quintile 2 (790 m–988 m)0.706 (0.633–0.789)<0.001
 Quintile 3 (988 m–1043 m)0.498 (0.438–0.567)<0.001
 Quintile 4 (1043 m–1125 m)0.560 (0.505–0.621)<0.001
 Quintile 5 (1128 m–1398 m)0.543 (0.483–0.610)<0.001
Yearly nighttime lightContinuous – increase of 1 on a scale from 0–63 (ranging from 0 to 2.0 in this dataset)0.385 (0.330–0.448)<0.001
Total confirmed malaria cases lagged 1 monthContinuous – increase of 100 cases1.049 (1.045–1.053)<0.001
Total malaria tests done (RDTs or microscopy)Continuous – increase of 1000 tests1.039 (1.034–1.045)<0.001
Sine-function for timeContinuous0.981 (0.919–1.047)0.560
Cosine-function for timeContinuous1.459 (1.319–1.615<0.001
TimeContinuous – increase of one month1.022 (1.016–1.029)<0.001
  1. N = 149 facilities, 5,587 months.