Table 5.
Patients with one or more displacement of 5mm in weeks 1–2: univariate and multivariate logistic regression models
| Category* | Data |
Univariate models |
Multivariate models |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Miss | n | 3 mm+ displacement | OR | (95% CI) | z | P | n | OR | (95% CI) | z | P | |
| T-stage | 2 | 655 | 318 | 1.07 | (0.85, 1.36) | 0.59 | 0.558 | 645 | – | – | – | – |
| Differentiation | 0 | 657 | 320 | 0.81 | (0.59, 1.12) | −1.28 | 0.202 | – | – | – | – | – |
| Age (quartile) | 0 | 657 | 320 | 1.02 | (0.88, 1.17) | 0.23 | 0.819 | – | 0.98 | (0.84, 1.14) | −0.28 | 0.778 |
| Risk group | 0 | 657 | 320 | 0.98 | (0.71, 1.36) | −0.12 | 0.901 | – | 1.07 | (0.75, 1.52) | 0.37 | 0.708 |
| Allocated treatment | 0 | 657 | 320 | 0.83 | (0.61, 1.12) | −1.21 | 0.225 | – | 0.91 | (0.66, 1.26) | −0.57 | 0.566 |
| Dose group | 0 | 657 | 320 | 0.60 | (0.17, 2.06) | −0.82 | 0.414 | – | – | – | – | – |
| Beam modification | 6 | 651 | 319 | 1.72 | (1.21, 2.45) | 3.03 | 0.002 | – | 1.85 | (1.09, 3.14) | 2.29 | 0.022 |
| Treatment verification | 2 | 655 | 319 | 1.49 | (1.08, 2.05) | 2.43 | 0.015 | – | 2.69 | (1.55, 4.68) | 3.51 | <0.001 |
| Phase I fields | 2 | 655 | 319 | 1.22 | (0.89, 1.67) | 1.24 | 0.214 | – | 1.16 | (0.82, 1.63) | 0.84 | 0.403 |
| Fractions imaged | 0 | 657 | 320 | 1.87 | (1.45, 2.40) | 4.88 | <0.001 | – | 1.56 | (1.38, 1.77) | 6.92 | <0.001 |
| Baseline bladder symptoms | 6 | 651 | 319 | 0.80 | (0.58, 1.10) | −1.40 | 0.161 | – | 0.78 | (0.56, 1.10) | −1.4 | 0.161 |
T-stage and differentiation were not included in the multivariate models because they were jointly represented in the risk group.
LMPA, low melting point alloy; MLC, multileaf collimator; EPI, electronic portal imaging.
Category (reference category is depicted in bold): T-stage = T1 vs T2 vs T3; Differentiation = Good vs moderate vs poor (based on differentiation or Gleason sum score, where available); Age = 46–62, 63–66, 67–70, 71 and over; Risk group = Low vs moderate (trial stratification factor); Allocated treatment = 74Gy/37 fractions vs 64 Gy/32 fractions; Beam modification = MLC vs LMPA; Treatment verification = EPI vs film; Phase I fields = three vs four; Total dose = <64Gy vs 64 Gy+; Number of fractions reported = 0–3 vs 4–6 vs 7+.