The independent effects of global intelligence and education at 18 y of age with respect to the risk of SDH during a median follow-up of 35 y in 440,742 men.

<p>Hazard ratios (HR) and 95% confidence intervals (95% CI) are presented for low, medium and high global intelligence and four different levels of education. The Cox regression models were adjusted for age at baseline, conscription place and year of conscription.</p

The risk of a dementia diagnosis in individuals with only one mild TBI (<i>n</i> = 108,463) and corresponding controls (<i>n</i> = 216,077), during follow-up.

<p>To model the effects, restricted cubic splines with four knots were used (resulting in three degrees of freedom), followed by fitting a proportional hazards model. TBI, traumatic brain injury.</p

Cohort characteristics at baseline.

<p>The first (prospective) cohort was matched according to TBI at baseline, and the risk of dementia was investigated during follow-up; the second cohort consisted of siblings with discordant TBI at baseline; the third (retrospective) cohort was matched according to dementia during follow-up, and diagnoses of TBI were investigated.</p

Associations between TBI and the risk of dementia diagnosis during follow-up in 491,252 individuals.

<p>To model the effects, restricted cubic splines with four knots were used (resulting in three degrees of freedom), followed by fitting a proportional hazards model. TBI, traumatic brain injury.</p

The risk of a dementia diagnosis in individuals with at least one nonmild TBI (<i>n</i> = 39,374) and corresponding controls (<i>n</i> = 77,924), during follow-up.

<p>To model the effects, restricted cubic splines with four knots were used (resulting in three degrees of freedom), followed by fitting a proportional hazards model. TBI, traumatic brain injury.</p

Baseline characteristics of 440,742 men studied based on occurrence of SDH during follow-up.

<p>*For comparing the distribution of the four different levels of education.</p

Associations between TBI and a dementia diagnosis during follow-up in 46,970 sibling pairs discordant for TBI.

<p>To model the effects, restricted cubic splines with four knots were used (resulting in three degrees of freedom), followed by fitting a proportional hazards model. TBI, traumatic brain injury.</p

Associations between dementia at baseline and previous TBI in the retrospective cohort (<i>n</i> = 404,887).

<p>Odds ratios and 95% CIs were derived from conditional logistic regression analysis.</p

Associations between TBI and the risk of dementia during follow-up in 46,970 full sibling pairs, discordant for TBI at baseline.

<p>Odds ratios and 95% CIs were derived from conditional logistic regression analysis.</p

Underlying mechanism for having a SDH during follow-up in a total of 440,742 men followed for a median of 35 y.

<p>HR are presented per SD decrease in cognitive performance according to underlying mechanism and in total. HRs for education are presented for those with more than 11 y of school with those with less than 9 y of school as reference, and per SD increase for physical fitness. The models were adjusted for age, conscription year, and place.</p