Table 1 Demographic and clinical characteristics of metformin use and non-use groups
Variable | Category | Cases (Metformin at time of diagnosis) | “Controls” (No metformin for ≥ 1 year prior and ≥ 1 year after diagnosis) | P-value |
|---|---|---|---|---|
N | 165 | 1066 | ||
Age | ||||
65–69 | 38 (23.0%) | 280 (26.3%) | 0.874 | |
70–74 | 49 (29.7%) | 289 (27.1%) | ||
75–79 | 44 (26.7%) | 257 (24.1%) | ||
80–84 | 25 (15.2%) | 168 (15.8%) | ||
85–90 | 6 (3.6%) | 52 (4.9%) | ||
= > 90 | 3 (1.8%) | 20 (1.9%) | ||
Mean age at diagnosis (± SD) | 74.55 ± 6.09 | 74.51 ± 6.35 | 0.934 | |
Elixhauser Comorbidity Index Score | ||||
0 | 43 (26.1%) | 637 (59.8%) | < 0.001 | |
1 | 40 (24.2%) | 197 (18.5%) | ||
2 | 30 (18.2%) | 96 (9.0%) | ||
3+ | 52 (31.5%) | 136 (12.8%) | ||
Gender | ||||
Female | 24 (14.5%) | 175 (16.4%) | 0.543 | |
Male | 141 (85.5%) | 891 (83.6%) | ||
Treatment type | ||||
Surgery+/−RT/CRT | 31 (18.8%) | 266 (25.0%) | 0.058 | |
RT+/-Surgery | 116 (70.3%) | 646 (60.6%) | ||
CRT+/-Surgery | 18 (10.9%) | 154 (14.4%) | ||
Primary site | ||||
Glottic larynx | 105 (63.6%) | 656 (61.5%) | 0.406 | |
Hypopharynx | 17 (10.3%) | 152 (14.3%) | ||
Nasopharynx | 12 (7.3%) | 55 (5.2%) | ||
Supraglottic larynx | 31 (18.8%) | 203 (19.0%) | ||