Table 2.
Model fitting and effect (HR and 95% CI), including regression coefficients (ß) and level of significance (ρ), of CNS trauma expressed by TBI severity and SCI comorbidity, controlling for potential confounders and risk factors for dementia
| Regression coefficients/predictors/P-value 1st row (all) 2nd row (men) 3rd row (women) |
Dementia model |
||
|---|---|---|---|
| Simplest; ß/HR (95% CI) ρ | Simplest + interaction of TBI severity with age; ß/HR (95% CI) ρ | Simplest + interaction of SCI with age; ß/HR (95% CI) ρ | |
| TBI severity | |||
| Mild (yes) | 1 | 1 | 1 |
| Unknown severity (concussion codes) versus mild | 0.09/1.10 (1.07–1.12)**** | 0.42/Fig. 2A**** | 0.09/1.10 (1.07–1.12)**** |
| 0.16/1.17 (1.13–1.22)**** | 0.78/Fig. 2B**** | 0.16/1.17 (1.13–1.22)**** | |
| 0.05/1.05 (1.02–1.08)*** | 0.02/Fig. 2B | 0.05/1.05 (1.02–1.08)*** | |
| Moderate versus mild | 0.11/1.12 (1.02–1.24)*** | 0.31/Fig. 2A | 0.11/1.12 (1.01–1.23)*** |
| −0.02/0.98 (0.84–1.15) | 0.16/Fig. 2B | −0.02/.98 (0.83–1.14) | |
| 0.21/1.23 (1.09–1.40)*** | 0.82/Fig. 2B | 0.21/1.23 (1.08–1.40)*** | |
| Severe versus mild | −0.04/0.97 (0.91–1.03) | 1.65/Fig. 2A**** | −0.04/0.96 (0.91–1.02) |
| −0.06/0.94 (0.86–1.02) | 1.96/Fig. 2B**** | −0.07/0.94 (0.86–1.02) | |
| 0.00/1.00 (0.92–1.09) | 1.47/Fig. 2B*** | 0.00/1.00 (0.91–1.09) | |
| Mild (yes) | 1 | 1 | 1 |
| SCI comorbidity | |||
| SCI (yes vs. no) | 0.08/1.08 (1.03–1.12)*** | 0.07/1.08 (1.03–1.12)*** | 1.35/(Fig. 3A)**** |
| 0.12/1.13 (1.06–1.21)*** | 0.12/1.13 (1.06–1.21)*** | 1.79/(Fig. 3B)**** | |
| 0.05/1.05 (1.00–1.11) | 0.05/1.05 (1.00–1.12) | 0.91/(Fig. 3B)*** | |
| Sex | |||
| Women | −0.13/0.88 (0.86–0.90)**** | −0.13/0.88 (0.86–0.90)**** | −0.13/0.88 (0.86–0.90)**** |
| Men | 1 | 1 | 1 |
| Age† | −0.05/0.96 (0.90–1.01) | −0.05/Supplementary Fig. 3, Suppl. File 2 | −0.04/Supplementary Fig. 4, Suppl. File 2 |
| −0.11/0.90 (0.86–0.97)*** | −0.11/Supplementary Fig. 3, Suppl. File 2*** | −0.10/Supplementary Fig. 4, Suppl. File 2*** | |
| 0.02/1.02 (0.93–1.13) | 0.02/Supplementary Fig. 3, Suppl. File 2 | 0.02/Supplementary Fig. 4, Suppl. File 2 | |
| Age2 | 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.01)**** | 0.00/1.00 (1.00–1.01)**** |
| 0.01/1.01 (1.00–1.01)**** | 0.01/1.01 (1.00–1.01)**** | 0.01/1.01 (1.00–1.01)**** | |
| 0.00/1.00 (1.00–1.01)**** | 0.00/1.00 (1.00–1.01)**** | 0.00/1.00 (1.00–1.01)**** | |
| Age3 | 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.00)**** |
| 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.00)**** | |
| 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.00)**** | 0.00/1.00 (1.00–1.00)**** | |
| Controlling variables | |||
| Neighborhood income 2nd quantile versus 1st quantile (poorest) | −0.07/0.94 (0.91–0.97)**** | −0.07/0.94 (0.91–0.97)**** | −0.07/0.94 (0.91–0.97)**** |
| −0.10/0.90 (0.89–0.96)*** | −0.10/0.9105 (0.86–0.95)*** | −0.10/0.90 (0.86–0.95)*** | |
| −0.05/0.96 (0.92–0.99)*** | −0.05/0.96 (0.92–0.99)*** | −0.05/0.96 (0.92–0.99)*** | |
| Neighborhood income 3rd quantile versus 1st quantile | −0.08/0.92 (0.89–0.95)**** | −0.08/0.92 (0.89–0.95)**** | −0.08/0.92 (0.90–0.95)**** |
| −0.12/0.89 (0.84–0.94)**** | −0.12/0.89 (0.84–0.94)**** | −0.12/0.89 (0.84–0.94)**** | |
| −0.06/0.94 (0.90–0.98)*** | −0.07/0.94 (0.90–0.98)*** | −0.07/0.94 (0.90–0.98)*** | |
| Neighborhood income 4th quantile versus 1st quantile | −0.11/0.90 (0.87–0.93)**** | −0.11/0.90 (0.87–0.93)**** | −0.11/0.90 (0.87–0.93)**** |
| −0.19/0.83 (0.79–0.87)**** | −0.19/0.83 (0.76–0.87)**** | −0.19/0.83 (0.79–0.88)**** | |
| −0.05/0.95 (0.91–0.99)*** | −0.05/0.95 (0.91–0.99)*** | −0.05/0.95 (0.91–0.99)*** | |
| Neighborhood income 5th quantile versus 1st quantile | −0.15/0.86 (0.83–0.89)**** | −0.15/0.86 (0.83–0.89)**** | −0.15/0.86 (0.83–0.89)**** |
| −0.23/0.80(0.750–0.84)**** | −0.23/0.80 (0.76–0.84)**** | −0.23/0.80 (0.76–0.84)**** | |
| −0.10/0.90 (0.86–0.94)**** | −0.10/0.90 (0.86–0.94)**** | −0.10/0.90 (0.86–0.94)**** | |
| Cerebrovascular disease (yes vs. no) | 0.36/1.43 (1.37–1.48)**** | 0.36/1.43(1.38–1.48)**** | 0.36/1.43 (1.38–1.481)**** |
| 0.37/1.45 (1.37–1.53)**** | 0.37/1.45 (1.38–1.53)**** | 0.37/1.45 (1.37–1.528)**** | |
| 0.34/1.40 (1.33–1.48)**** | 0.34/1.40 (1.33–1.48)**** | 0.34/1.40 (1.33–1.478)**** | |
| Ischemic heart disease (yes vs. no) | −0.11/0.90 (0.87–0.93)**** | −0.11/0.90 (0.87–0.93)**** | −0.11/0.90 (0.87–0.93)**** |
| −0.16/0.85 (0.81–0.90)**** | −0.16/0.85 (0.81–0.90)**** | −0.16/0.85 (0.81–0.90)**** | |
| −0.06/0.94 (0.90–0.98)*** | −0.07/0.94 (0.90–0.98)*** | −0.06/0.94 (0.90–0.98)*** | |
| Diseases of arteries, arterioles and capillaries (yes vs. no) | 0.11/1.12 (1.05–1.19)*** | 0.11/1.12 (1.05–1.19)*** | 0.11/1.12 (1.05–1.19)*** |
| 0.16/1.18 (1.08–1.28)*** | 0.16/1.18 (1.08–1.28)*** | 0.16/1.18 (1.08–1.28)*** | |
| 0.03/1.03 (0.94–1.14) | 0.03/1.03 (0.94–1.14) | 0.03/1.03 (0.94–1.14) | |
| Atrial fibrillation (yes vs. no) | −0.06/0.94 (0.91–0.98)*** | −0.06/0.95 (0.91–0.98)*** | −0.06/0.95 (0.91–0.98)*** |
| −0.07/0.93 (0.88–0.99)*** | −0.07/0.94 (0.884–0.99)*** | −0.07/0.94 (0.88–0.99)*** | |
| −0.05/0.95 (0.91–1.00) | −0.05/0.95 (0.91–1.00) | −0.05/0.95 (0.91–1.00) | |
| Heart failure (yes vs. no) | 0.15/1.16 (1.110–1.21)**** | 0.15/1.16 (1.11–1.21)**** | 0.15/1.16 (1.11–1.21)**** |
| 0.18/1.20 (1.13–1.28)**** | 0.18/1.20 (1.13–1.28)**** | 0.18/1.20 (1.13–1.28)**** | |
| 0.121.13 (1.06–1.19)**** | 0.12/1.13 (1.06–1.19)**** | 0.12/1.13 (1.06–1.19)**** | |
| Obesity (yes vs. no) | −0.05/0.95 (0.84–1.08) | −0.05/0.95 (0.834–1.08) | −0.05/0.95 (0.83–1.08) |
| −0.12/0.89 (0.70–1.11) | −0.13/0.88 (0.70–1.11) | −0.13/0.88 (0.70–1.11) | |
| −0.01/0.99 (0.85–1.16) | −0.01/0.99 (0.85–1.16) | −0.01/0.99 (0.85–1.15) | |
| Tobacco smoking (yes vs. no) | 0.67/1.95 (1.45–2.56)**** | 0.66/1.94 (1.48–2.56)**** | 0.67/1.95 (1.48–2.56)**** |
| 0.42/1.52 (1.02–2.28)*** | 0.42/1.520 (1.02–2.27)*** | 0.42/1.53 (1.02–2.28)*** | |
| 0.91/2.49 (1.71–3.64)**** | 0.91/2.491 (1.71–3.64)**** | 0.91/2.49 (1.70–3.63)**** | |
| Hyperlipidemia (yes vs. no) | 0.04/1.04 (0.99–1.099) | 0.04/1.04 (0.99–1.09) | 0.04/1.04 (0.99–1.09) |
| 0.09/1.10 (1.02–1.18)*** | 0.09/1.09 (1.02–1.18)*** | 0.09/1.09 (1.02–1.18)*** | |
| −0.00/1.00 (0.93–1.07) | −0.01/0.99 (0.93–1.07) | −0.00/1.00 (0.93–1.07) | |
| Diabetes mellitus (yes vs. no) | 0.38/1.46 (1.42–1.50)**** | 0.38/1.457 (1.42–1.50)**** | 0.38/1.46 (1.42–1.50)**** |
| 0.40/1.49 (1.42–1.55)**** | 0.39/1.484 (1.42–1.55)**** | 0.40/1.49 (1.42–1.55)**** | |
| 0.36/1.44(1.38–1.49)**** | 0.36/1.435 (1.38–1.49)**** | 0.36/1.44 (1.38–1.49)**** | |
| Depression (yes vs. no) | 0.60/1.82(1.73–1.91)**** | 0.60/1.82 (1.73–1.91)**** | 0.59/1.811 (1.72–1.91)**** |
| 0.70/2.01 (1.85–2.18)**** | 0.69/2.00 (1.85–2.18)**** | 0.70/2.004 (1.85–2.18)**** | |
| 0.54/1.71 (1.61–1.83)**** | 0.54/1.71 (1.61–1.83)**** | 0.54/1.709 (1.60–1.82)**** | |
| Vision impairments (yes vs. no) | −0.06/0.95 (0.89–1.00) | −0.06/0.946 (0.89–1.01) | −0.06/0.95 (0.89–1.00) |
| −0.01/0.99 (0.91–1.09) | −0.01/0.994 (0.91–1.09) | −0.01/1.00 (0.91–1.09) | |
| −0.09/0.92 (0.85–0.99)*** | −0.09/0.918 (0.85–0.99)*** | −0.09/0.92 (0.85–0.99)*** | |
| Hearing loss (yes vs. no) | 0.16/1.18 (1.01–1.37)*** | 0.16/1.18 (1.01–1.37)*** | 0.16/1.18 (1.01–1.37)*** |
| 0.21/1.24 (0.99–1.55) | 0.21/1.24 (0.99–1.55) | 0.21/1.24 (0.99–1.55) | |
| 0.12/1.13 (0.91–1.38) | 0.12/1.13 (0.92–1.39) | 0.12/1.13 (0.92–1.39) | |
| Sleep disorder (yes vs. no) | 0.22/1.25 (1.15–1.36)**** | 0.22/1.25 (1.15–1.36)**** | 0.22/1.25 (1.14–1.36)**** |
| 0.23/1.26 (1.11–1.42)*** | 0.22/1.25 (1.11–1.41)*** | 0.23/1.25 (1.11–1.41)*** | |
| 0.21/1.23 (1.09–1.40)*** | 0.21/1.24 (1.09–1.40)*** | 0.21/1.23 (1.09–1.40)*** | |
| Model fitting | |||
| LRχ2 | 111134.13**** | 111172.20**** | 111172.94**** |
| 52,654.88**** | 52,692.07**** | 52,686.80**** | |
| 54,048.52**** | 54,059.47**** | 54,057.45**** | |
| AIC | 735762.68 | 735688.60 | 735687.87 |
| 277549.06 | 277517.88 | 277519.15 | |
| 413829.46 | 413824.51 | 413822.52 | |
| Degree of freedom | 18 | 21 | 19 |
| 17 | 20 | 18 | |
| 17 | 20 | 18 | |
| Corrected C-index | 0.93 | 0.93 | 0.93 |
| 0.95 | 0.95 | 0.95 | |
| 0.90 | 0.90 | 0.90 | |
NOTE. Corrected C-index for all models ranged from 0.90 to 0.95.
ρ = level of significance: ***P < .001; ****P < .0001.
Abbreviations: AIC, Akaike information criterion; CI, confidence interval; CNS, central nervous system; HR, hazard ratio; LR, likelihood ratio; TBI, traumatic brain injury; SCI, spinal cord injury; Suppl., Supplement.
†
Significant nonlinearity was observed: a restricted cubic spline transformation was used.