Table 3.

Univariate and multivariate analyses to identify the risk factors predictive of CNS involvement

Variable	Univariate analysis			Multivariate analysis
	OR	95% CI	P value	OR	95% CI	P value
Age*	5.654	2.01-15.904	0.001	5.933	1.82-19.343	0.003
Sex	0.786	0.319-1.932	0.599	-	-	-
WBC†	4.069	1.616-10.244	0.003	3.136	1.083-9.078	0.035
Platelet§	2.303	0.755-7.026	0.143	2.804	0.799-9.837	0.107
LDH‡	1.931	0.688-5.425	0.212	-	-	-
FAB M4¶	3.143	1.266-7.803	0.014	2.023	0.646-6.341	0.227
inv(16) ∆	2.899	0.609-13.79	0.181	1.176	0.277-10.612	0.562
11q23 abnormalities#	9.307	2.615-33.123	0.001	5.548	1.208-25.489	0.028

Only variables with P value < 0.2 in the univariate analysis were incorporated into the multivariate logistic regression analysis.

*Age ≤ 45 y relative to age > 45 y.

†WBC greater than or equal to 50,000/μL vs less than 50,000/μL.

§Platelet greater than or equal to 30,000/μL vs less than 30,000/μL.

‡LDH greater than or equal to two times the upper limit of normal vs less than two times the upper limit of normal.

¶French-American-British M4 morphology vs others.

^∆Inversion of chromosome 16 vs others.

^#chromosome translocations involving 11q23 vs others.

Abbreviation: CNS, central nervous system; OR, odds ratio; CI, confidence interval; WBC, white blood cell; LDH, lactate dehydrogenase.