Dear All,

Please, I would like to gently ask you all two questions about the analysis of repeated measures on STATA 14.0

1# Is it possible to linear regression instead of Anova repeated measures ?==> regress calories phase instead of anova calories phase subject , repeated (phase)
if not why ?

I have tested both method and I have obtained a results completely different:

Result from regression


------------------------------------------------------------------------------
calories | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
phase | 5.550875 47.43901 0.12 0.907 -87.91544 99.01719
_cons | 1944.094 102.48 18.97 0.000 1742.183 2146.004
------------------------------------------------------------------------------

AND result from anova


Number of obs = 234 R-squared = 0.9876
Root MSE = .044943 Adj R-squared = 0.9812

Source | Partial SS df MS F Prob>F
-----------+----------------------------------------------------
Model | 24.775995 79 .31362019 155.27 0.0000
|
phase | .53173289 2 .26586644 131.63 0.0000
subject | 24.244262 77 .31486054 155.88 0.0000
|
Residual | .31105595 154 .00201984
-----------+----------------------------------------------------
Total | 25.087051 233 .10766975


Between-subjects error term: subject
Levels: 78 (77 df)
Lowest b.s.e. variable: subject

Repeated variable: phase
Huynh-Feldt epsilon = 0.9420
Greenhouse-Geisser epsilon = 0.9205
Box's conservative epsilon = 0.5000

------------ Prob > F ------------
Source | df F Regular H-F G-G Box
-----------+----------------------------------------------------
phase | 2 131.63 0.0000 0.0000 0.0000 0.0000
Residual | 154
----------------------------------------------------------------

2# If data is non-normal distributed, Is it possible to run log-transformation and then use Anova test ?


Thank you for your help.