Baseline characteristics of patients who underwent cervical disc arthroplasty per year, from 2007 to 2017.
| Demographic | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | Total | P Value |
| Age, y | 46.60 ± 1.2 | 45.76 ± 0.8 | 46.34 ± 0.7 | 45.79 ± 0.8 | 47.56 ± 0.9 | 45.86 ± 1.0 | 46.78 ± 0.9 | 47.29 ± 0.9 | 47.18 ± 0.8 | 46.63 ± 0.7 | 47.32 ± 0.7 | 46.7 ± 0.3 | 0.0043 |
| Length of stay, d | 1.72 ± 0.2 | 1.62 ± 0.2 | 1.74 ± 0.2 | 1.50 ± 0.2 | 1.72 ± 0.2 | 1.67 ± 0.2 | 1.67 ± 0.2 | 1.56 ± 0.4 | 1.65 ± 0.1 | 1.48 ± 0.1 | 1.59 ± 0.1 | 1.6 ± 0.1 | 0.1853 |
| Female | 163 (51.4) | 273 (49.9) | 333 (49.9) | 323 (52.1) | 286 (48.8) | 192 (45.6) | 234 (49.1) | 303 (50.2) | 371 (53.7) | 446 (52.5) | 451 (53.1) | 3375 (50.9) | 0.26 |
| Caucasian | 206 (65.0) | 384 (70.2) | 485 (72.7) | 469 (75.7) | 410 (70.0) | 316 (75.1) | 335 (70.2) | 421 (69.8) | 511 (74.0) | 655 (77.1) | 641 (77.1) | 4833 (72.9) | <0.001 |
| Medicare payment | 29 (9.2) | 24 (4.4) | 49 (7.3) | 42 (6.7) | 56 (9.6) | 34 (8.1) | 45 (9.4) | 66 (10.9) | 84 (12.2) | 88 (10.4) | 107 (12.6) | 624 (9.4) | <0.001 |
| Private insurance | 318 (68.8) | 360 (65.8) | 397 (59.61) | 356 (57.5) | 354 (60.7) | 262 (62.5) | 331 (69.5) | 381 (63.5) | 444 (64.3) | 541 (63.7) | 550 (64.8) | 4294 (64.8) | |
| 75th–100th zip code quartile | 86 (27.1) | 146 (26.7) | 149 (22.3) | 148 (23.9) | 196 (33.4) | 126 (29.9) | 151 (31.7) | 182 (30.2) | 205 (29.7) | 257 (30.2) | 274 (32.3) | 1920 (29.0) | <0.001 |
| Large bed size | 150 (47.3) | 317 (58.0) | 390 (58.5) | 332 (53.5) | 388 (66.2) | 247 (58.7) | 295 (61.8) | 273 (45.3) | 328 (47.5) | 417 (49.1) | 433 (51.0) | 3570 (53.86) | <0.001 |
| Private, investment hospital | 65 (20.5) | 107 (19.6) | 86 (12.9) | 129 (20.8) | 127 (21.7) | 90 (21.4) | 127 (26.6) | 131 (21.7) | 154 (22.3) | 187 (22.0) | 176 (20.7) | 1631 (24.6) | <0.001 |
| Urban | 158 (49.8) | 250 (45.7) | 373 (57.5) | 302 (49.2) | 219 (54.9) | 199 (47.3) | 239 (50.1) | 157 (26.0) | 208 (30.1) | 254 (29.9) | 214 (25.2) | 2573 (38.8) | <0.001 |
| Rural | 10 (3.15) | 32 (5.85) | 23 (3.54) | 20 (3.26) | 13 (2.24) | 17 (4.04) | 11 (2.31) | 27 (4.48) | 35 (5.07) | 26 (3.06) | 26 (3.06) | 240 (3.6) | |
| Western region | 69 (21.77) | 130 (23.77) | 131 (19.64) | 131 (21.13) | 219 (37.37) | 126 (29.93) | 151 (31.66) | 180 (29.85) | 185 (26.77) | 257 (30.24) | 288 (33.92) | 1867 (28.2) | <0.001 |
Note: Data are reported as n (%) except for age and length of stay, which are reported as mean ± SD. Significance was obtained through linear regression with P < 0.05 as significant.