Association between Residential Proximity to PERC Dry Cleaning Establishments and Kidney Cancer in New York City

Table 3

Rate ratios for exposure levels and covariates from the main effects only model.

Variable	Rate ratio	95% CI
By Exposure level
Exposure level 1	1.00
Exposure level 2	1.14	1.03	1.27
Exposure level 3	1.09	0.97	1.21
Exposure level 4	1.17	1.05	1.32
Exposure level 5	1.15	1.01	1.30
By population density
Low	1.00
Middle	0.84	0.76	0.93
High	0.66	0.59	0.74
By median household income (MHI)
Low	1.00
Middle	0.96	0.89	1.04
High	1.04	0.95	1.14
By age group
Age 45–54	1.00
Age 55–64	2.22	2.02	2.44
Age 65–74	3.77	3.44	4.14
Age 75+	4.22	3.85	4.64
By race
Caucasian (white)	1.00
African American (black)	0.89	0.83	0.95
By gender
Male	1.00
Female	0.44	0.41	0.47