Age Variance in the Survival of United States Pediatric Leukemia Patients (1973–2006)

Table 2

Mortality associated with age at diagnosis and other factors in pediatric patients with leukemia, 1973–2006.

Covariates	Hazard ratio (HR)	99% CI	𝑃
Age at diagnosis (yrs)
<1.0	1.00	ref	ref
1.0–4.0	0.26	0.22–0.30	<0.0001
5.0–9.0	0.33	0.28–0.39	<0.0001
10.0–14.0	0.56	0.48–0.66	<0.0001
15.0–19.0	0.89	0.77–1.04	0.05
Sex
Male	1.00	ref	ref
Female	0.86	0.80–0.93	<0.0001
Race
White	1.00	ref	ref
Black	1.54	1.36–1.74	<0.0001
Cell type
T-cell	1.00	ref	ref
B-cell, B-precursor	0.49	0.41–0.59	<0.0001
Year of diagnosis
1973–1977	1.00	ref	ref
1978–1982	0.73	0.64–0.84	<0.0001
1983–1987	0.60	0.52–0.69	<0.0001
1988–1992	0.42	0.36–0.48	<0.0001
1993–1997	0.38	0.33–0.43	<0.0001
1998–2002	0.33	0.29–0.37	<0.0001
2003–2006	0.29	0.25–0.34	<0.0001
No. of primaries
1.0	1.00	ref	ref
≥2.0	1.75	1.40–2.20	<0.0001
Beam radiation
Yes	1.00	ref	ref
No	0.84	0.77–0.92	<0.0001

Notes and Abbreviations. The significance level was 0.01. CI: confidence interval.