Table 2.
Factors associated with the persistence of imatinib initial therapy
|
Characteristics |
Non-persistenta |
Persistent |
χ2 |
OR for being persistent (95% CI) |
p value |
|---|---|---|---|---|---|
| (n = 479) | (n = 303) | (p-value) | |||
| Age at diagnosis, y, n (%) |
|
|
2.08 (0.15) |
|
|
| ≥40, |
308 (64.3) |
210 (69.3) |
|
1.4 (0.9 to 2.1) |
0.15 |
| <40 |
171 (35.7) |
93 (30.7) |
|
1 (referent) |
|
| Gender, n (%) |
|
|
0.44 (0.51) |
|
|
| Male |
281 (58.7) |
185 (61.1) |
|
1.4 (0.9 to 2.1) |
0.10 |
| Female |
198 (41.3) |
118 (38.9) |
|
1 (referent) |
|
| Charlson comorbidity score, n (%) |
|
|
1.39 (0.24) |
|
|
| >0 |
215 (44.9) |
123 (40.6) |
|
0.8 (0.5 to 1.1) |
0.16 |
| =0 |
264 (55.1) |
180 (59.4) |
|
1 (referent) |
|
| CML diagnosis, n (%) |
|
|
11.97(<0.001) |
|
|
| ≥2004 |
260 (54.3) |
126 (41.6) |
|
4.1 (2.2 to 7.9) |
<.0001 |
| <2004 |
219 (45.7) |
177 (48.4) |
|
1 (referent) |
|
| CML severity, n (%) |
|
|
7.60 (0.06) |
|
|
| Unknown |
28 (5.9) |
24 (7.9) |
|
0.6 (0.2 to 1.6) |
0.20 |
| Low |
2 (0.4) |
2 (0.7) |
|
1.4 (0.1 to 19.0) |
0.77 |
| Moderate |
378 (78.9) |
251 (82.8) |
|
1.5 (0.8 to 3.0) |
0.30 |
| High |
71 (14.8) |
26 (8.6) |
|
1 (referent) |
|
| Prior treatment, n (%) | |||||
| Hydroxyurea |
342 (71.4) |
225 (74.3) |
0.76 (0.38) |
1.8 (1.1 to 2.8) |
0.02 |
| Busulfan |
8 (1.7) |
9 (3.0) |
1.48 (0.22) |
0.5 (0.1 to 2.0) |
0.34 |
| IFNα/Ara-C |
72 (15.0) |
75 (24.8) |
11.49(<0.001) |
1.9 (1.1 to 3.3) |
0.02 |
| Mean time to imatinib initiation, month (SD) |
14.1 (19.6) |
15.4 (19.4) |
0.89 (0.37)d |
1.0 (0.99 to 1.02) |
0.42 |
| Mean starting daily dose, mg/day (SD)b |
362 (141) |
375 (108) |
1.35 (0.18) d |
1.1 (0.97 to 1.34) |
0.11 |
| Mean treatment duration, months (SD) |
16.5 (16.8) |
41.2 (14.2) |
21.94 (<.0001) d |
1.1 (1.09 to 1.13) |
<.0001 |
| HSCT post-index date, n (%) | 35 (7.3) | 2 (0.7) | 18.19(<.0001) | 0.1 (0.02 to 0.5) | 0.01 |
a. Patients were considered persistent if they were taking imatinib without interruption (exceeding a 60-day permissible gap) for at least 18 months since the start of therapy.
b. Excluding patients with a single imatinib claim (n = 19).
c. OR = odds ratio, each OR of the variable was adjusted by the other factors in the logistic regression model.
Abbreviations: CML, chronic myeloid leukemia; IFNα, interferon-α; Ara-C, cytarabine; HSCT, hematopoietic stem cell transplantation.
d. t test for numerical outcomes.