Table 4 Parameter estimates for models of variance components, time, treatment (T1 and T2) and interaction (of time on treatment) main effects on the Perceived Stress Scale (PSS) group means.
Variance Components | Time Main Effects | Treatment Main Effects | Interaction Main Effects | |
|---|---|---|---|---|
Fixed effects | Coeff. (S.E.) | Coeff. (S.E.) | Coeff. (S.E.) | Coeff. (S.E.) |
β Constant | 17.639 (0.533) | 18.444 (0.597) | 16.479 (0.598) | 15.836 (0.614) |
Time | -1.999 (0.669)* | -2.223 (0.665)* | -0.500 (0.770) | |
T2 | 6.958 (1.241)* | 8.092 (1.441)* | ||
T3 | 5.372 (1.164)* | 8.101 (1.365)* | ||
T2 × time | -2.786 (1.679) | |||
T3 × time | -6.059 (1.554)* | |||
Random effects | ||||
Subject level residual variance | 15.498 (4.260) | 16.639 (4.200) | 8.226 (3.063) | 9.867 (2.956) |
Time level residual variance | 18.496 (3.115) | 16.599 (2.801) | 16.721 (2.801) | 13.930 (2.334) |
-2 log likelihood | 1020.264 | 1011.772 | 974.964 | 960.204 |