Table 4. Impact of enrollment on trials on event-free and overall survival in adjusted modelsa.

	Event-free survival		Overall survival
Characteristics	HR (95% CI)	P-value	HR (95% CI)	P-value
Variables included in multiple regression
Demographic: age, gender, ethnicity, era	0.60 (0.48–0.76)	<0.0001	0.61 (0.45–0.82)	0.001
Leukaemia: white count, CNS status, immunophenotype, cytogenetics	0.72 (0.53–0.99)	0.040	0.75 (0.50–1.13)	0.163
Socioeconomic: distance and income quintile	0.64 (0.50–0.82)	0.0003	0.63 (0.45–0.86)	0.004
Demographic, leukaemic and socioeconomic factors	0.67 (0.47–0.95)	0.023	0.69 (0.44–1.08)	0.102

Abbreviations: CI=confidence interval; CNS=central nervous system; HR=hazard ratio.

^aMultiple Cox proportional hazards model in which the estimates reflect the adjusted effect of enrollment on trials where a HR<1 indicates better survival.