| Characteristics | No. of incarcerations | Person-years | Incidence rate per 100 000 person-years | Unadjusted model | Adjusted model |
|---|---|---|---|---|---|
| IR (95% CI) | HR (95% CI) | HR (95% CI) | |||
| Overall | 3321 | 9 238 892 | 35.9 (34.7-37.2) | ||
| TBI* | |||||
| No | 2965 | 8891856 | 33.5 (32.1-34.5) | 1.00 | 1.00 |
| Yes | 356 | 347126 | 102.6 (91.9-113.2) | 3.26 (2.91-3.64) | 2.47 (2.21-2.77) |
| Age, yr | |||||
| 18-21 | 1297 | 3262825 | 39.8 (37.6-42.0) | 1.00 | (1.00) |
| 22-24 | 873 | 2449332 | 35.6 (33.3-38.1) | 0.90 (0.82-0.98) | 0.87 (0.80-0.95) |
| 25-28 | 1151 | 3526825 | 32.6 (30.8-34.6) | 0.82 (0.76-0.89) | 0.77 (0.71-0.83) |
| Rural residence | |||||
| No | 2966 | 8115993 | 36.5 (35.2-37.9) | 1.00 | 1.00 |
| Yes | 355 | 1123388 | 31.6 (28.1-35.1) | 0.87 (0.77-0.97) | 1.03 (0.91-1.17) |
| Material deprivation† | |||||
| Q1 (least deprived) | 439 | 2204177 | 19.9 (18.1-21.9) | 1.00 | 1.00 |
| Q2 | 569 | 2129505 | 26.7 (24.6-29.0) | 1.34 (1.19-1.52) | 1.29 (1.14-1.47) |
| Q3 | 639 | 1933271 | 33.0 (30.6-35.7) | 1.66 (1.47-1.88) | 1.48 (1.30-1.68) |
| Q4 | 704 | 1627296 | 43.3 (40.2-46.6) | 2.17 (1.93-2.45) | 1.76 (1.55-2.00) |
| Q5 (most deprived) | 970 | 1344731 | 72.1 (67.7-76.8) | 3.62 (3.24-4.06) | 2.54 (2.23-2.89) |
| Ethnic concentration† | |||||
| Q1 (least) | 416 | 1344374 | 29.8 (27.1-32.8) | 1.00 | 1.00 |
| Q2 | 563 | 1773547 | 30.5 (28.1-33.2) | 1.03 (0.90-1.16) | 1.03 (0.91-1.17) |
| Q3 | 531 | 1656420 | 30.8 (28.3-33.6) | 1.04 (0.91-1.18) | 1.00 (0.87-1.14) |
| Q4 | 662 | 1883787 | 33.8 (33.1-36.5) | 1.14 (1.00-1.28) | 1.04 (0.91-1.18) |
| Q5 (most) | 1149 | 2580852 | 42.8 (40.4-45.3) | 1.44 (1.29-1.61) | 1.06 (0.94-1.20) |
| Residential instability† | |||||
| Q1 (least unstable) | 485 | 2189635 | 22.3 (20.2-24.2) | 1.00 | 1.00 |
| Q2 | 492 | 2012090 | 24.4 (22.4-26.7) | 1.10 (0.97-1.25) | 1.01 (0.89-1.15) |
| Q3 | 611 | 1783041 | 34.3 (31.6-37.1) | 1.55 (1.37-1.75) | 1.20 (1.06-1.37) |
| Q4 | 919 | 1952207 | 47.1 (44.1-50.2) | 2.12 (1.90-2.37) | 1.38 (1.22-1.56) |
| Q5 (most unstable) | 814 | 1301008 | 62.5 (58.4-67.0) | 2.82 (2.52-3.16) | 1.74 (1.53-1.97) |
| Previous TBI‡,§ | |||||
| No | 2801 | 8570118 | 32.7 (31.5-33.9) | 1.00 | 1.00 |
| Yes | 520 | 668864 | 77.7 71.3-84.7 | 2.38 (2.17-2.61) | 1.88 (1.71-2.07) |
| Psychotic mood disorder‡,¶,** | |||||
| No | 3233 | 9159856 | 35.3 (34.1-36.5) | 1.00 | 1.00 |
| Yes | 88 | 79126 | 111.2 (90.2-137.1) | 3.15 (2.55-3.89) | 1.02 (0.82-1.27) |
| Nonpsychotic mood disorder‡,¶,†† | |||||
| No | 2255 | 7957300 | 28.3 (27.2-29.5) | 1.00 | 1.00 |
| Yes | 1066 | 1281682 | 83.2 (78.3-88.3) | 2.93 (2.72-3.16) | 2.25 (2.09-2.44) |
| Substance use disorder‡,¶,‡‡ | |||||
| No | 2988 | 9081002 | 32.9 (31.7-34.1) | 1.00 | 1.00 |
| Yes | 333 | 157980 | 210.8 (189.3-234.7) | 6.40 (5.72-7.17) | 3.67 (3.25-4.13) |
| Social problems‡,¶,§§ | |||||
| No | 3169 | 9099282 | 34.8 (33.6-36.1) | 1.00 | 1.00 |
| Yes | 152 | 139700 | 108.9 (92.8-127.6) | 3.12 (2.66-3.68) | 1.71 (1.45-2.02) |
Note: CI = confidence interval, HR = hazard ratio, ICD-9 = International Classification of Diseases, 9th Revision, [Clinical Modification], IR = incidence rate, Q = quintile, TBI = traumatic brain injury. Values in boldface type represent confidence limits that do not cross 1.
*At least 1 TBI between June 30, 1997, and Mar. 31, 2011.
†As per the Ontario Marginalization Index,42 by quintile.
‡Based on medical records from physician visits, including primary care providers.
§History of TBI between Apr. 1, 1993, and June 30, 1997.
¶History of diagnosis between Jan. 1, 1995, and June 30, 1997.
**Defined as hospital visit for ICD-9 diagnostic codes 295-298.
††Defined as hospital visit for ICD-9 diagnostic codes 300-302, 306, 309 and 301.
‡‡Defined as hospital visit for ICD-9 diagnostic codes 291-292 and 303-304.
§§Defined as hospital visit for ICD-9 diagnostic codes 897-906 and 909.