Table 5.

Risk of select neuropathological endpoints among those with baseline TBI with LOC ^a ≤1 hour or >1 hour at baseline, compared to those with no TBI with LOC at baseline.

		Hour or less (n = 126)		Over an hour (n = 19)
Neuropath outcomeb	N	RRc (95% CI)	p	RRc (95% CI)	p
Braak stage V or VI	750	1.01 (0.74, 1.36)	0.96	1.12 (0.49, 2.04)	0.77
LATE stage >0	751	1.00 (0.75, 1.31)	0.99	1.01 (0.52, 1.64)	0.97
Any cerebral or deep microvascular lesions	749	0.97 (0.73, 1.27)	0.81	1.20 (0.55, 1.96)	0.53
Any cerebral microvascular lesions	749	0.92 (0.66, 1.28)	0.65	1.06 (0.45, 2.00)	0.88
Any deep microvascular lesions	749	0.87 (0.58, 1.31)	0.53	1.58 (0.66, 2.90)	0.21
Any Macroinfarcts	771	1.04 (0.70, 1.51)	0.83	0.97 (0.37, 1.94)	0.94
Ratio of fixed brain weight to expected weightd	621	1.00 (0.97, 1.02)	0.96	0.99 (0.93, 1.06)	0.88
Centimeters of cerebral cortical atrophye	669	1.16 (0.94, 1.43)	0.16	1.53 (0.86, 2.80)	0.17

^aAt least one report of TBI with LOC as of ACT study entry, based on ACT study data, or, when available, on BISQ self-report or proxy or chart review.

^bSome outcomes were too rare to assess by LOC duration.

^cAdjusted rate ratios (RR) and 95% confidence intervals (CI) are from Poisson regressions modified with robust standard errors, adjusting for age at death, sex, education, any Apoe4 alleles, TBI with LOC after baseline, and ACT study cohort. Results were weighted back to the full cohort in a bootstrapping procedure that accounted for the error in estimating the weights, resulting in wider confidence intervals and higher p-values than in unweighted results.

^dTotal fixed brain weight divided by the expected brain weight, where the expected brain weight was calculated as 200 + the posterior fossa contents weight/0.15.

^eAtrophy defined by dilatation in the lateral ventricles at the level of the temporal tip.