Table 4.
Summary of Direct and Total Effects from Simultaneous Equations Regression Model Examining sTREM2 and Total Tau as Outcomes
| Standardized Direct Effects | Standardized Total Effects | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| sTREM2 | t-tau | sTREM2 | t-tau | |||||||||||||
| Beta | SE | t | P | Beta | SE | t | P | Beta | SE | t | P | Beta | SE | t | P | |
| Age | 0.28 | 0.12 | 2.43 | 0.0149 | -- | -- | -- | -- | 0.35 | 0.10 | 3.59 | 0.0003 | 0.18 | 0.08 | 2.14 | 0.0323 |
| BMI | -- | -- | -- | -- | −0.20 | 0.12 | −1.65 | 0.10 | −0.09 | 0.10 | −0.88 | 0.38 | −0.24 | 0.12 | −1.97 | 0.0489 |
| Race | −0.28 | 0.14 | −2.02 | 0.0432 | -- | -- | -- | -- | −0.35 | 0.11 | −3.15 | 0.0016 | −0.18 | 0.09 | −2.04 | 0.0411 |
| CHII | -- | -- | -- | -- | 0.20 | 0.11 | 1.80 | 0.07 | 0.09 | 0.10 | 0.90 | 0.37 | 0.25 | 0.12 | 2.17 | 0.0300 |
| sTREM2 | -- | -- | -- | -- | 0.52 | 0.20 | 2.61 | 0.0091 | -- | -- | -- | -- | 0.64 | 0.37 | 1.74 | 0.08 |
| t-tau | 0.36 | 0.36 | 0.99 | 0.32 | -- | -- | -- | -- | 0.44 | 0.55 | 0.80 | 0.43 | -- | -- | -- | -- |
Note. In the initial model, the p-values for paths between age and t-tau, as well as between BMI and sTREM2 were greater than 0.10 and were therefore removed from the final model. Based on independent regression, the CHII was only estimated to have a direct effect on t-tau. BMI = body mass index, CHII = cumulative head impact index, t-tau = total tau, SE = standard error. Beta is standardized and bolded values highlight statistical significance. For race, 1 = African American and 0 = Caucasian.