Table 4. Stratification analysis of malaria risk factors stratifying by altitude uses the Mantel Haenszel method in highland villages, northwest Ethiopia, 2013.

Variables	COR	1500–1750 m	1750–2000 m	Above 2000 m	Adjusted (Mantel-Haenszel)
		OR	OR	OR	ORMH	95%CI	X2	P value
Sex	4.07	3.83	1.13	4.86	4.08	3.00,5.40	95.6	0.0001
Occupation	1.76	4.0	1.54	1.66	1.78	1.33,2.33	16.1	0.0001
ITN own	1.015	1.19	0.87	1.05	1.057	0.77,1.44	0.1	0.7
IRS sprayed	0.644	0.62	0.51	0.91	0.616	0.35,1.08	2.9	0.08
Travel away home	1.969	1.02	2.68	2.15	1.966	1.59,2.43	39.8	0.0001
Plants used for fence	1.94	3.15	1.37	1.65	2.02	1.41,2.91	14.8	0.0001
Long grass near the house	1.011	1.52	0.79	0.90	1.208	0.76,1.38	0.02	0.89
Forest near the house	2.379	1.48	2.32	2.60	2.379	1.84,3.08	44.8	0.0001
Short grasses near the house	1.247	1.60	0.67	1.33	1.265	0.99,1.61	3.7	0.055
Bushes	1.55	1.47	1.04	0.66	1.549	0.80,2.99	3.13	0.188

OR_MH: adjusted odds ratio using Mantel-Haenszel method, COR: crude odds ratio.