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

Table 4

Rate ratios for exposure levels and interactions of effect modifiers.

	Rate ratio all population	Effect modifier	Effect modifier level	Rate ratio (RR) for certain level effect modifier	95% confidence interval for RR
Exposure level 1	1	None
Exposure level 2	1.15∗	None
	(95% CI 1.04, 1.27)
Exposure level 3	1.102	Population density	Low	0.90	0.74	1.08
	(95% CI 1.00, 1.24)		Middle	1.16	1.01	1.33
			High	1.19	1.01	1.41
Exposure level 4	1.27∗	Race	White	1.35	1.19	1.53
	(95% CI 1.13, 1.42)		Black	1.08	0.83	1.40
Exposure level 5			Low/mid MHI
			Age = 45–54	0.87	0.70	1.07
			Age = 55–64	1.20	0.94	1.53
			Age = 65–74	1.21	1.00	1.46
	1.16∗	MHI and Age	Age = 75 +	1.24	1.04	1.49
	(95% CI 1.02, 1.33)		High MHI
			Age = 45–54	1.14	0.87	1.48
			Age = 55–64	1.57	1.18	2.09
			Age = 65–74	1.59	1.24	2.03
			Age = 75 +	1.63	1.28	2.07

∗Statistically significant at 𝑃<.05.