. 2015 Sep 29;14:374. doi: 10.1186/s12936-015-0865-2

Table 3.

Associations between measures of urbanicity and incidence of malaria stratified by study site

Urbanicity metric	Exposure categories	Walukuba			Kihihi			Nagongera
Urbanicity metric	Exposure categories	Malaria incidence (PY)^a	IRR^b (95 % CI)	P	Malaria incidence (PY)^a	IRR^b (95 % CI)	P	Malaria incidence (PY)^a	IRR^b (95 % CI)	P
Household density^c	≤80	0.35 (94.2)	1.02 (0.58–1.81)	0.94	1.21 (720.2)	0.48 (0.20–1.17)	0.11	2.17 (746.9)	N/A
Household density^c	>80	0.36 (512.5)	1.02 (0.58–1.81)	0.94	0.60 (51.6)	0.48 (0.20–1.17)	0.11	None	N/A
NDVI^d	>0.45	0.43 (197.6)	0.77 (0.46–1.28)	0.31	1.19 (586.4)	0.97 (0.64–1.45)	0.87	1.91 (519.6)	1.35 (1.07–1.70)	0.01
NDVI^d	≤0.45	0.32 (409.1)	0.77 (0.46–1.28)	0.31	1.11 (185.3)	0.97 (0.64–1.45)	0.87	2.75 (227.3)	1.35 (1.07–1.70)	0.01
Night-time lights	≤3	0.36 (418.3)	1.04 (0.62–1.75)	0.88	1.17 (771.8)	N/A		2.17 (746.9)	N/A
Night-time lights	>3	0.36 (188.4)	1.04 (0.62–1.75)	0.88	None	N/A		None	N/A
Land cover	≤20 %	0.37 (346.6)	1.04 (0.62–1.73)	0.89	Not measured			Not measured
Land cover	>20 %	0.35 (260.1)	1.04 (0.62–1.73)	0.89	Not measured			Not measured
Composite score^e	Low	0.37 (419.0)	0.97 (0.57–1.65)	0.92	1.21 (720.2)	0.48 (0.20–1.17)	0.11	2.17 (746.9)	N/A
Composite score^e	High	0.34 (187.7)	0.97 (0.57–1.65)	0.92	0.60 (51.6)	0.48 (0.20–1.17)	0.11	None	N/A

^aNumber of episodes of malaria per person years (PY) of follow-up

^bIncidence rate ratio adjusted for mean age during follow-up and repeated measures in the same household

^cNumber of households within 100 m radius from a participating household

^dNormalized difference vegetation index

^e1 point for each individual urbanicity metric: Walukuba (low = 0–2, high = 3–4), Kihihi and Nagongera (low = 0–1, high = 2)