Topography-derived wetness indices are associated with household-level malaria risk in two communities in the western Kenyan highlands

Table 2 Malaria odds ratios associated with distance to wetness categories

		Controlling for person-time and year			Controlling for person-time, year, and elevation
Wetness category	Wetness values	OR	95% CI		OR	95% CI
		for a 100 m increase in distance			for a 100 m increase in distance
Kipsamoite
1 (driest)	2.9–4.8	1.084	1.046	1.123	1.065	1.005	1.129
2	4.8–6.7	1.078	0.879	1.322	0.812	0.610	1.079
3	6.7–8.6	0.204	0.060	0.695	0.295	0.089	0.974
4	8.6–10.5	1.031	0.810	1.312	1.253	0.938	1.674
5	10.5–12.4	1.033	0.868	1.230	1.103	0.923	1.318
6	12.4–14.3	0.940	0.818	1.080	1.066	0.915	1.243
7	14.3–16.2	0.894	0.817	0.978	0.993	0.874	1.128
8	16.2–18.1	0.882	0.815	0.953	0.924	0.841	1.016
9	18.1–20.0	0.870	0.812	0.934	0.892	0.827	0.963
10 (wettest)	20.0–21.8	0.920	0.885	0.957	0.932	0.894	0.972
Kapsisiywa
1 (driest)	4.4–6.3	0.987	0.902	1.080	0.971	0.883	1.067
2	6.3–8.2	0.749	0.515	1.089	0.684	0.465	1.006
3	8.2–10.1	1.070	0.752	1.524	1.106	0.776	1.575
4	10.1–12.0	1.003	0.895	1.125	1.027	0.905	1.165
5	12.0–13.9	0.972	0.896	1.055	0.982	0.899	1.072
6	13.9–15.8	0.932	0.858	1.011	0.936	0.860	1.019
7	15.8–17.7	0.929	0.862	1.002	0.933	0.863	1.009
8	17.7–19.6	0.924	0.856	0.997	0.927	0.853	1.007
9	19.6–21.5	0.917	0.854	0.984	0.909	0.838	0.987
10 (wettest)	21.5–23.4	0.903	0.857	0.953	0.894	0.841	0.950

Odds ratios for the presence of any household malaria in 2003–2004 associated with 100 m increases in distance between houses and the nearest 10 m² grid-cell in each of ten wetness categories.

ISSN: 1475-2875