Table 3. Cox regression analysis of PFS.
| Covariate |
HR (95% CI) |
|
|---|---|---|
| Univariate modela (n=116) | Multivariate model (n=101) | |
| Dose reduced after ⩾12 months (yes vs no) | 0.42 (0.21–0.86)b | 0.47 (0.23–0.98) |
| Dose reduced before 12 months (yes vs no) | 1.73 (1.03–2.91)b | |
| Age, years | 1.02 (1.00–1.05) | |
| ISS disease stage at baseline (stage 1, 2, 3) | 1.45 (0.92–2.28) | |
| Bone marrow cellularity, % | 1.01 (1.00–1.02) | |
| Bone marrow cellularity (<33% vs ⩾33%) | 1.43 (0.86–2.36) | |
| Serum albumin at 12 months, g/dl | 0.53 (0.25–1.26) | 0.29 (0.11–0.75) |
| Calcium at baseline (⩽10% vs >10%) | 0.56 (0.30–1.07) | |
| Calcium at 12 months (⩽10% vs >10%) | 2.38 (0.73–7.73) | |
| Neutrophils at 12 months, % | 1.02 (1.00–1.04) | 1.02 (1.00–1.04) |
| Neutrophils (absolute) at 12 months, × 103/l | 1.06 (0.84–1.34) | |
| M-protein at 12 months, g/l | 1.07 (1.00–1.14)b | 1.07 (1.00–1.14) |
| ECOG score at baseline (⩾1 vs 0) | 1.00 (0.60–1.67) | |
| Chi-square(df) | Chi-square(4)=16.60 | |
| P=0.003 | ||
| AIC=423.56 | ||
Abbreviations: AIC, Akaike's information criterion; CI, confidence interval; df, degrees of freedom; ECOG, Eastern Cooperative Oncology Group; HR, hazard ratio; ISS, International Staging System.
a
All listed univariate covariates had a P-value of <0.25 and were considered in the multivariate analysis.
b
P<0.05 for the univariate model.