Table IV.

Tetrasomy rates of all 24 chromosomes between formaldehyde-exposed and control groups^a

Chromosome	IRRb	95% CIc	P-value
4	1.64	1.21–2.21	0.0012
15	3.10	1.53–6.28	0.0017
17	2.40	1.33–4.32	0.0036
14	2.13	1.19–3.81	0.011
3	2.40	1.22–4.75	0.012
18	2.14	1.14–4.01	0.018
8	1.84	1.10–3.07	0.020
12	1.56	1.06–2.29	0.025
2	2.28	1.08–4.82	0.031
10	2.26	1.06–4.82	0.034
6	1.87	0.99–3.54	0.054
7	2.02	0.95–4.30	0.067
13	2.00	0.95–4.21	0.069
16	1.72	0.96–3.09	0.070
20	2.08	0.87–4.94	0.099
1	1.77	0.89–3.53	0.10
21	1.45	0.89–2.34	0.13
19	1.53	0.74–3.15	0.25
11	1.38	0.76–2.52	0.29
5	1.41	0.68–2.94	0.36
9	1.36	0.66–2.82	0.41
22	1.24	0.61–2.53	0.55
Y	0.85	0.25–2.88	0.79
X (M)d	N/A	N/A	1.00

^aData listed according to P-values.

^bIRR, adjusted for age and sex, except for sex in the analysis of X and Y chromosomes.

^c95% confidence interval.

^dX chromosome in males.