112014-04-23 12:25:05PeterWatson102014-04-23 12:24:29PeterWatson92014-04-23 12:21:08PeterWatson82014-04-23 12:19:10PeterWatson72014-04-23 12:17:23PeterWatson62014-04-23 11:55:23PeterWatson52014-04-23 11:36:48PeterWatson42014-04-23 11:32:06PeterWatson32014-04-23 11:31:39PeterWatson22014-04-23 11:25:19PeterWatson12014-04-23 11:24:51PeterWatson

We illustrate using the data below with one time factor df() with three time points wach with a different covariate value cv() Using MANOVA we obtain Tests of Significance for T1 using UNIQUE sums of squares Source SS DF MS F Sig of F WITHIN+RESIDUAL 33.81 5 6.76 REGRESSION 173.11 1 173.11 25.60 .004 GROUP 5.09 1 5.09 .75 .425 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Regression analysis for WITHIN+RESIDUAL error term --- Individual Univariate .9500 confidence intervals Dependent variable .. T4 COVARIATE B Beta Std. Err. t-Value Sig of t Lower -95% CL-Upper T4 1.398 1.054 0.276 5.06 .004 0.6878 2.108 Tests involving 'TRIAL' Within-Subject Effect. AVERAGED Tests of Significance for dv using UNIQUE sums of square Source SS DF MS F Sig of F WITHIN+RESIDUAL 24.51 11 2.23 REGRESSION .33 1 .33 .15 .709 TRIAL 45.94 2 22.97 10.31 .003 GROUP BY TRIAL 3.27 2 1.63 .73 .502 We then need to reformat the data into 'long format' using the varstocases syntax and then fit the repeated measures data with varying covariate as a mixed model. Source Num df Denom DF F Sig of F Intercept 1 12.80 27.75 .000 group 1 5.881 2.177 .191 trial 2 10.858 12.708 .001 group by trial 2 10.287 0.704 .517 cv 1 12.24 0.081 .780 The results using the two approaches are similar except for the group main effect which although non-significant in both has a lower significance level for the MANOVA.