| Age < 70 vs. ≥70 | 1.23 | 0.76–2.01 | 0.40 | | | |
| Gender Male vs. Female | 0.80 | 1.41–1.53 | 0.49 | | | |
| ECOG Performance status 0–1 vs.2–3 | 4.14 | 1.58–10.8 | 0.0037 | 2.30 | 0.81–6.52 | 0.12 |
| BMI < 20 vs. ≥20 | 0.51 | 0.62–7.47 | 0.227 | | | |
| Primary site Oropharynx vs. others | 1.02 | 0.62–1.68 | 0.94 | | | |
| T-classification 1–2 vs. 3–4 | 1.97 | 1.25–3.12 | 0.0035 | 1.56 | 0.95–2.57 | 0.082 |
| N-classification 0-2b vs. 2c-3 | 2.31 | 1.43–3.73 | < 0.001 | 1.57 | 0.90–2.73 | 0.11 |
| Histology SCC vs. others | 0.36 | 0.12–1.08 | 0.069 | | | |
| Brinkman index < 500 vs. ≥500 | 1.16 | 0.73–1.84 | 0.54 | | | |
| Habitual alcoholic consumption Yes vs. No | 0.64 | 0.40–1.01 | 0.055 | | | |
| Use of ACEi or ARB Yes vs. No | 0.97 | 0.55–1.69 | 0.91 | | | |
| Use of PPI or H2 blocker Yes vs. No | 1.14 | 0.73–1.75 | 0.59 | | | |
| Oral hygiene before treatment Good vs. Poor | 1.58 | 1.01–2.48 | 0.043 | 1.11 | 0.68–1.83 | 0.68 |
| Coexistence of other malignancies Yes vs. No | 0.89 | 0.64–1.23 | 0.48 | | | |
| Charlson comorbidity index 0–1 vs. ≥2 | 1.32 | 0.79–2.22 | 0.29 | | | |
| Serum albumin before treatment Within normal limits vs. less than normal range | 2.78 | 1.59–4.77 | < 0.001 | 1.88 | 0.95–3.75 | 0.069 |
| Hemoglobin before treatment Within normal limits vs. less than normal range | 1.75 | 1.09–2.79 | 0.020 | 1.07 | 0.60–1.91 | 0.82 |
| Use of sleeping pills before treatment Yes .vs No | 0.63 | 0.41–0.98 | 0.042 | 0.75 | 0.39–1.43 | 0.38 |
| Induction chemotherapy Yes vs. No | 1.15 | 0.69–1.89 | 0.60 | | | |
| Concurrent chemotherapy regimen CDDP vs. others | 1.15 | 0.70–1.89 | 0.57 | | | |
| Radiation technique Conventional 3D-CRT vs. IMRT | 0.60 | 0.37–0.98 | 0.043 | 0.65 | 0.38–1.12 | 0.12 |
| Radiation dose 70Gy vs. <70Gy | 4.13 | 1.18–14.4 | 0.026 | 3.70 | 0.97–14.1 | 0.056 |
| Irradiation field Local vs. whole neck | 0.98 | 0.56–1.72 | 0.95 | | | |
| Percutaneous endoscopic gastrostomy prior to treatment Yes vs. No | 0.50 | 0.31–0.80 | 0.041 | 0.68 | 0.40–1.15 | 0.15 |
| Treatment Inpatient vs. Outpatient | 0.62 | 0.40–0.96 | 0.032 | 0.86 | 0.52–1.40 | 0.53 |
| The worst mucositis grade during treatment 1–2 vs. 3–4 | 1.09 | 0.70–1.70 | 0.70 | | | |
| The worst dysphagia score during treatment 1–2 vs. 3–4 | 1.39 | 0.89–2.17 | 0.15 | | | |
| Aspiration pneumonia during treatment Yes vs. No | 0.38 | 0.23–0.62 | < 0.001 | 0.52 | 0.30–0.90 | 0.020 |
