TABLE II.
Predictors of Chelation Adherencea
| Predictors of deferoxamine adherence | Slope (SE) | P-value |
|---|---|---|
| Problems sticking themselves b | 0.056 c | |
| Adults | −3.08 (1.52) | |
| Children | −0.31 (1.58) | |
| Smoking in the past year | −11.32 (5.53) | 0.045 |
| Predictors of deferoxamine adherence ≥90% | Odds ratio (95% CI) | P-value |
|
| ||
| Problems sticking themselvesb | 0.018c | |
| Adults | 0.59 [0.37, 0.95] | |
| Children | 1.16 [0.57, 2.35] | |
| Predictors of deferoxamine ≥5 nights/weekd | Odds ratio (95% CI) | P-value |
|
| ||
| Problems wearing pump | 0.57 [0.31, 1.05] | 0.071 |
| Number of transfusions in past year | 1.12 [0.98, 1.28] | 0.090 |
| Predictors of deferasirox adherence | Slope (SE) | P-value |
|
| ||
| Age | ||
| Linear term | −0.63 (0.31) | 0.046 |
| Quadratic term | 0.01 (0.01) | 0.032 |
| Bodily pain quality of life scalee | 0.07 (0.04) | 0.060 |
| Depressionf | −1.09 (0.30) | <0.001 |
| Predictors of deferasirox Adherence ≥ 90% | Odds ratio (95% CI) | P-value |
|
| ||
| Depressionf | 0.76 [0.65, 0.90] | 0.001 |
Abbreviations: SE, standard error; CI, confidence interval.
predictors significant in bivariate analysis, controlling for age, at level 0.10 were entered into a multivariate analysis of covariance model with backwards elimination. For deferoxamine adherence, predictors significant in bivariate analysis were age (quadratic effect), problems wearing their pump, problems sticking themselves (adults only), smoking in the past year (yes/no), and days per week of deferoxamine use. For deferasirox adherence, predictors significant in bivariate analysis were age (quadratic effect), number of transfusions in the last year, problems with side effects (adults only), the bodily pain, role physical, general heath, and vitality quality of life scales, anxiety, and depression.
Problems measured on a 1–5 scale: never through a lot. Higher numbers indicate more problems.
Significant interaction between predictor and age group (adults age 18+ vs. children). Significant effect in adults only.
Includes those prescribed < 5 nights/weeks with 100% adherence.
Bodily pain scale of the SF-36. Higher score indicates higher quality of life, i.e., less pain.
HADS depression scale. Higher score indicates increased depression.