Smoking, environmental tobacco smoke, and risk of renal cell cancer: a population-based case-control study

BMC Cancer

Table 5 Descriptive statistics for cigarette smoking and ETS exposure (home and workplace), by age-decade^a,b

Age (years)	Cigarette duration (yrs.)^c		Cigarette pack-years^d		Cigarette cessation (yrs.)^e		Home ETS years^f		Work ETS years^g
	Mean	St. dev.	Mean	St. dev.	Mean	St. dev.	Mean	St. dev.	Mean	St. dev.
20 – 29	2.80	3.36	0.61	0.92	4.00	-	2.50	3.00	1.00	2.24
30 – 39	7.62	8.95	4.18	5.75	4.33	4.16	11.14	9.87	2.29	3.73
40 – 49	11.30	13.75	8.36	13.36	14.29	11.18	13.93	11.39	7.16	9.76
50 – 59	17.05	16.06	18.09	22.33	16.85	12.05	13.78	13.99	8.11	10.84
60 – 69	20.64	19.76	20.68	27.45	23.20	13.34	17.00	16.43	12.88	14.53
70 – 79	19.72	20.45	21.08	27.74	28.61	15.50	19.00	16.30	10.28	14.39
≥ 80	12.88	18.13	11.69	25.56	36.48	16.16	19.03	21.17	9.26	15.49
Total	17.44	18.67	17.49	25.33	24.66	15.39	16.45	16.17	9.65	13.40

^a Spearman's correlation coefficients reported for both variables as continuous.
^b Cigarette duration and pack-years reported for full sample (N = 672); Cigarette cessation reported for ex-smokers only (N = 305); ETS statistics reported for never-smokers only (N = 263).
^c F = 5.163, p < 0.0001; Spearman's ρ = 0.048, p = 0.215
^d F = 4.668, p < 0.0001; Spearman's ρ = 0.022, p = 0.564
^e F = 10.822, p < 0.0001; Spearman's ρ = 0.388, p < 0.0001
^f F = 1.354, p = 0.234; Spearman's ρ = 0.102, p = 0.121
^g F = 1.699, p = 0.122; Spearman's ρ = 0.029, p = 0.636

ISSN: 1471-2407