Table 2.
Demographics and Baseline Characteristics of At-Risk Patients and Matched Controlsa
| Variable | Overall (N = 300,428) | At Risk (n = 150,214) | Control (n = 150,214) | P Value |
|---|---|---|---|---|
| Age, years | 68.7 (14.8) | 68.7 (14.8) | 68.7 (14.8) | 1.000 |
| Gender | ||||
| Male | 98,208 (32.7) | 49,104 (32.7) | 49,104 (32.7) | 1.000 |
| Female | 202,220 (67.3) | 101,110 (67.3) | 101,110 (67.3) | |
| Region | ||||
| Northeast | 37,824 (12.6) | 18,912 (12.6) | 18,912 (12.6) | 1.000 |
| Midwest | 74,846 (24.9) | 37,423 (24.9) | 37423 (24.9) | |
| South | 139,876 (46.6) | 69,938 (46.6) | 69,938 (46.6) | |
| West | 47,882 (15.9) | 23,941 (15.9) | 23,941 (15.9) | |
| CCI score | ||||
| 0b | 69,026 (23.0) | 38,963 (25.9) | 30,063 (20.0) | < 0.0001 |
| 1 | 65,370 (21.8) | 32,810 (21.8) | 32,560 (21.7) | |
| 2 | 82,250 (27.4) | 40,106 (26.7) | 42,144 (28.1) | |
| 3 | 77882 (25.9) | 38,335 (25.5) | 39,547 (26.3) | |
| ≥ 4 | 5,900 (2.0) | 0 (0.0) | 5,900 (3.9) | |
| Disability | ||||
| Aged without ESRD | 195,638 (65.1) | 97,819 (65.1) | 97,819 (65.1) | 1.000 |
| Aged with ESRD | 3,708 (1.2) | 1,854 (1.2) | 1,854 (1.2) | 1.000 |
| Disabled without ESRD | 96,230 (32.0) | 48,115 (32.0) | 48,115 (32.0) | 1.000 |
| Disabled with ESRD | 4,580 (1.5) | 2,290 (1.5) | 2,290 (1.5) | 1.000 |
| ESRD only | 272 (0.1) | 136 (0.1) | 136 (0.1) | 1.000 |
| Cormorbidities unrelated to pain | ||||
| Other substance abuse | 23,998 (8.0) | 16,329 (10.9) | 7,669 (5.1) | < 0.0001 |
| Nonopioid poisoning | 2,616 (0.9) | 1,559 (1.0) | 1,057 (0.7) | < 0.0001 |
| Psychiatric disorders | 1,466 (0.5) | 599 (0.4) | 867 (0.6) | < 0.0001 |
| HIV/AIDS | 2,332 (0.8) | 1,278 (0.9) | 1,054 (0.7) | < 0.0001 |
| Endocarditis | 1,400 (0.5) | 851 (0.6) | 549 (0.4) | < 0.0001 |
| Skin infections/abscesses | 30,323 (10.1) | 17,738 (11.8) | 12,585 (8.4) | < 0.0001 |
| Gastrointestinal bleed | 57,934 (19.3) | 34,809 (23.2) | 23,125 (15.4) | < 0.0001 |
| Cirrhosis/chronic or acute liver disease | 11,347 (3.8) | 6,849 (4.6) | 4,498 (3.0) | < 0.0001 |
| Hepatitis A, B, C | 173 (0.1) | 123 (0.1) | 50 (0.0) | < 0.0001 |
| Alcoholic hepatitis | NA | NA | NA | NA |
| Other hepatitis | 24 (0.0) | 14 (0.0) | 10 (0.0) | 0.4142 |
| Pancreatitis | 3,515 (1.2) | 2,291 (1.5) | 1,224 (0.8) | < 0.0001 |
| Sexually transmitted disease | 8,223 (2.7) | 4,422 (2.9) | 3,801 (2.5) | < 0.0001 |
| Herpes simplex | 1,521 (0.5) | 862 (0.6) | 659 (0.4) | < 0.0001 |
| Burns | 1,102 (0.4) | 668 (0.4) | 434 (0.3) | < 0.0001 |
| Trauma | 74,629 (24.8) | 44,034 (29.3) | 30,595 (20.4) | < 0.0001 |
| Motor vehicle accidents | 1,190 (0.4) | 712 (0.5) | 478 (0.3) | < 0.0001 |
| Comorbidities related to pain | ||||
| Cancer | 37,402 (12.4) | 19,803 (13.2) | 17,599 (11.7) | < 0.0001 |
| Low back pain | 102,521 (34.1) | 63,489 (42.3) | 39,032 (26.0) | < 0.0001 |
| Other back/neck disorders | 80,808 (26.9) | 49,480 (32.9) | 31,328 (20.9) | < 0.0001 |
| Arthritis | 182,506 (60.7) | 102,519 (68.2) | 79,987 (53.2) | < 0.0001 |
| Neuropathic pain | 50,883 (16.9) | 30,658 (20.4) | 20,225 (13.5) | < 0.0001 |
| Fibromyalgia | 20,680 (6.9) | 13,461 (9.0) | 7,219 (4.8) | < 0.0001 |
| Headache/migraine | 25,725 (8.6) | 16,550 (11.0) | 9,175 (6.1) | < 0.0001 |
aValues in this table are presented as mean (%).
bFor patients who did not have any encounters related to defined ICD-9-CM codes for CCI comorbidities during 6-month pre-index period and aged < 60 years,
CCI score is zero.
CCI = Charlson Comorbidity Index; ESRD = end-stage renal disease; HIV/AIDS = human immunodeficiency virus/acquired immunodeficiency syndrome;
ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; NA = not applicable.