Table 1.
Demographic characteristics of lumbar spine surgery patients with and without hypothyroidism
| Variable | Hypothyroidism | Whole non-hypothyroidism | P value | Matched non-hypothyroidism | P value |
|---|---|---|---|---|---|
| N | 101,763 | 771,347 | – | – | – |
| Age in years, median | 66 | 59 | < 0.001 | – | – |
| Age group n (%) | < 0.001 | 0.112 | |||
| 18–44 | 7,031 (6.91%) | 145,702 (18.89%) | 7,196 (7.07%) | ||
| 45–64 | 40,609 (39.91%) | 352,998 (45.76%) | 40,925 (40.22%) | ||
| 65–74 | 33,555 (32.97%) | 182,137 (23.61%) | 33,391 (32.81%) | ||
| ≥ 75 | 20,568 (20.21%) | 90,510 (11.73%) | 20,251 (19.90%) | ||
| Gender n (%) | < 0.001 | 0.05 | |||
| Male | 23,301 (22.90%) | 397,323 (51.51%) | 23,678 (23.27%) | ||
| Female | 78,462 (77.10%) | 374,024 (48.49%) | 78,085 (76.73%) | ||
| Race n (%) | < 0.001 | 0.111 | |||
| White | 83,463 (82.02%) | 579,887 (75.18%) | 83,507 (82.06%) | ||
| Black | 3,931 (3.86%) | 61,716 (8.01%) | 3,994 (3.92%) | ||
| Hispanic | 4,363 (4.29%) | 45,393 (5.88%) | 4,404 (4.33%) | ||
| Asian or Pacific Islander | 864 (0.85%) | 9,420 (1.22%) | 847 (0.83%) | ||
| Native American | 337 (0.33%) | 3,344 (0.43%) | 268 (0.26%) | ||
| Other | 8805 (8.65%) | 71,587 (9.28%) | 8,743 (8.59%) | ||
| Bed size of hospital n (%) | < 0.001 | 0.337 | |||
| Small | 18,729 (18.40%) | 140,279 (18.19%) | 18,532 (18.21%) | ||
| Medium | 25,328 (24.90%) | 188,965 (24.50%) | 25,210 (24.77%) | ||
| Large | 57,706 (56.71%) | 442,103 (57.32%) | 58,021 (57.02%) | ||
| Type of hospital n (%) | < 0.001 | 0.662 | |||
| Nonteaching | 37,453 (36.80%) | 294,087 (38.13%) | 37,358 (36.71%) | ||
| Teaching | 64,310 (63.20%) | 477,260 (61.87%) | 64,405 (63.29%) | ||
| Hospital location n (%) | < 0.001 | 0.494 | |||
| Rural | 4,180 (4.11%) | 39,975 (4.41%) | 4,119 (4.05%) | ||
| Urban | 97,583 (95.89%) | 737,372 (95.59%) | 97,644 (95.95%) | ||
| Charlson comorbidity index subgroup | < 0.001 | 0.926 | |||
| 0 | 3 (0.00%) | 199,936 (25.92%) | 3 (0.00%) | ||
| 1 | 12,580 (12.36%) | 217,839 (28.24%) | 12,609 (12.39%) | ||
| 2 | 26,032 (25.58%) | 172,424 (22.35%) | 25,898 (25.45%) | ||
| ≥ 3 | 63,148 (62.05%) | 181,148 (23.48%) | 63,253 (62.16%) | ||
| Admission type n (%) | < 0.001 | 0.019 | |||
| Non-elective | 12,949 (12.72%) | 110,739 (14.36%) | 13,305 (13.07%) | ||
| Elective | 88,814 (87.27%) | 660,608 (85.64%) | 88,458 (86.9%) | ||
| Location/teaching status of hospital n (%) | < 0.001 | 0.765 | |||
| Rural | 4,180 (4.11%) | 33,975 (4.40%) | 4,119 (4.05%) | ||
| Urban nonteaching | 33,273 (32.69%) | 260,112 (33.72%) | 33,239 (32.66%) | ||
| Urban teachin | 64,310 (63.19%) | 477,260 (61.88%) | 64,405 (63.29%) | ||
| Chronic pulmonary disease | < 0.001 | ||||
| n (%) | 0.073 | ||||
| Yes | 20,794 (20.43%) | 118,389 (15.35%) | 21,121 (20.76%) | ||
| No | 80,969 (79.57%) | 652,958 (84.65%) | 80,642 (79.24%) | ||
| Diabetes n (%) | < 0.001 | 0.664 | |||
| Yes | 25,602 (25.16%) | 145,415 (18.85%) | 25,687 (25.24%) | ||
| No | 76,161 (74.84%) | 625,932 (81.15%) | 76,076 (74.76%) | ||
| Drug abuse n (%) | < 0.001 | 0.439 | |||
| Yes | 1,375 (1.35%) | 13,030 (1.69%) | 1,335 (1.31%) | ||
| No | 100,388 (98.65%) | 75,8317 (98.31%) | 100,428 (98.69%) | ||
| Hypertension n (%) | < 0.001 | 0.198 | |||
| Yes | 65,577 (64.44%) | 399,388 (51.78%) | 65,299 (64.17%) | ||
| No | 36,186 (35.56%) | 371,959 (48.22%) | 36,464 (35.83%) | ||
| Alcohol abuse n (%) | < 0.001 | 0.499 | |||
| Yes | 942 (0.93%) | 12,598 (1.63%) | 913 (0.89%) | ||
| No | 100,821 (99.07%) | 758,749 (98.37%) | 100,850 (99.01%) |