Table 4.
Patients with one or more displacement of at least 3mm in weeks 3–6: 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 | 639 | 226 | 1.34 | (1.04, 1.72) | 2.28 | 0.023 | 630 | – | – | – | – |
| Differentiation | 0 | 641 | 226 | 0.76 | (0.55, 1.07) | −1.58 | 0.113 | – | – | – | – | – |
| Age (quartile) | 0 | 641 | 226 | 1.01 | (0.87, 1.17) | 0.13 | 0.900 | – | 0.96 | (0.82, 1.13) | −0.47 | 0.638 |
| Risk group | 0 | 641 | 226 | 1.56 | (1.11, 2.19) | 2.54 | 0.011 | – | 1.32 | (0.90, 1.95) | 1.43 | 0.153 |
| Allocated treatment | 0 | 641 | 226 | 1.14 | (0.83, 1.58) | 0.81 | 0.420 | – | 1.13 | (0.78, 1.62) | 0.65 | 0.518 |
| Dose group | 0 | 641 | 226 | 0.45 | (0.10, 2.16) | −0.99 | 0.321 | – | – | – | – | – |
| Beam modification | 5 | 636 | 224 | 2.24 | (1.50, 3.34) | 3.97 | <0.001 | – | 1.00 | (0.53, 1.86) | −0.01 | 0.991 |
| Treatment verification | 1 | 640 | 226 | 2.05 | (1.43, 2.93) | 3.91 | <0.001 | – | 2.01 | (1.14, 3.56) | 2.4 | 0.016 |
| Phase I fields | 1 | 640 | 226 | 1.92 | (1.36, 2.71) | 3.70 | <0.001 | – | 1.27 | (0.86, 1.88) | 1.22 | 0.222 |
| Fractions imaged | 0 | 641 | 226 | 3.98 | (2.97, 5.33) | 9.28 | <0.001 | – | 1.74 | (1.53, 1.98) | 8.29 | <0.001 |
| Baseline bladder symptoms | 6 | 635 | 226 | 0.97 | (0.69, 1.37) | −0.15 | 0.882 | – | 0.92 | (0.63, 1.35) | −0.42 | 0.677 |
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 4–5 vs 6–8 vs 9+.