TABLE 3.

Comparison of Annual Health Care Utilization Between Early and Late TKI Initiator Patients

	Average Annual Utilization (mean ± SD)		Unadjusted		Adjusted
	Patients Who Initiated TKI Therapy		IRRa	P Value	IRRa	P Value
	≤ 1 Month from First CML Diagnosis (n = 397)	Within >1-12 Months from First CML Diagnosis (n = 80)
Outpatient physician visits	17.49 ± 9.81	17.80 ± 14.89	0.98	0.86	1.01	0.89
Emergency room visits	0.54 ± 1.98	0.79 ± 2.11	0.69	0.29	0.73	0.27
All-cause hospitalizations	0.08 ± 0.45	0.26 ± 0.82	0.29	< 0.01b	0.35	0.02b
CML-specific hospitalizations	0.04 ± 0.24	0.21 ± 0.77	0.19	< 0.01b	0.27	< 0.01b
Number of prescriptions (all drugs)	34.35 ± 27.22	37.60 ± 31.81	0.91	0.38	0.88	0.09
Number of TKI prescriptions	10.23 ± 3.41	9.79 ± 4.48	1.05	0.41	0.99	0.77
Number of non-TKI prescriptions	24.12 ± 26.54	27.81 ± 30.60	0.87	0.29	0.81	0.06

^a An IRR >1 indicates that early initiators had higher incidence of incurring medical services compared with late initiators. IRRs were estimated using multivariable negative binomial regressions.

^b Significant at the 5% level.

CML = chronic myeloid leukemia; IRR = incidence rate ratio; SD = standard deviation; TKI = tyrosine kinase inhibitor.