Skip to main content
. Author manuscript; available in PMC: 2011 Sep 14.
Published in final edited form as: J Clin Psychopharmacol. 2010 Aug;30(4):396–403. doi: 10.1097/JCP.0b013e3181e617a1

Table 3.

General Linear Model of Primary and Secondary Measures

Variable Degrees Freedom F-Statistic P-Value Effect Size Partial-Eta Squared Observed Power
NE-YBOCS Total NE-YBOCS Total - Trend (1,30) 6.791 .014 NS .713
Interaction (1,30) .089 .767 NS .060
Arm of Study (1,30) 2.891 .099 .132 .377
NE-YBOCS Thoughts/Urge NE-YBOCS Thoughts/Urge - Trend (1,30) 2.105 .157 .231 .290
Interaction (1,30) .119 .732 NS .063
Arm of Study (1,30) 4.555 .041 NS .542
NE-YBOCS Behavior NE-YBOCS Behavior - Trend (1,30) 9.016 .005 .185 .828
Interaction (1,30) .023 .882 NS .052
Arm of Study (1,30) .609 .441 NS .118
Skin Picking Scale Skin Picking Scale - Trend (1,30) 13.692 .001 NS .947
Interaction (1,30) .837 .367 NS .144
Arm of Study (1,30) .124 .727 NS .063
SP-SAS SP-SAS - Trend (1,30) 14.168 .001 NS .954
Interaction (1,30) .388 .538 NS .093
Arm of Study (1,30) .033 .858 NS .054
CGI Severity CGI Severity -Trend (1,30) 3.857 .059 .612 .477
Interaction (1,30) .429 .518 NS .097
Arm of Study (1,30) 1.098 .303 NS .174
SDS SDS - Trend (1,30) 47.389 <.001 .313 1.00
Interaction (1,30) .013 .909 NS .051
Arm of Study (1,30) .243 .625 NS .077
HAM-D HAM-D - Trend (1,30) 3.369 .076 .321 .427
Interaction (1,30) 2.299 .140 NS .312
Arm of Study (1,30) 2.698 .111 NS .356
HAM-A HAM-A - Trend (1,30) 2.695 .111 .114 .356
Interaction (1,30) .802 .378 NS .140
Arm of Study (1,30) 2.847 .102 NS .372

Trend refers to trend over time across arms; significance indicates that by combining placebo and active scores together scores at one time point were higher than scores at the other time point regardless of arm of the study;

Interaction tests whether there is an interaction between scores at baseline versus endpoint (i.e. slope of line) and the arm of the study;

Arm of the study tests whether one group’s average scores are higher than the other group across time points.

Abbreviations: NE-YBOCS = Yale Brown Obsessive Compulsive Scale Modified for Neurotic Excoriation; SP-SAS = Skin Picking Symptom Assessment Scale; CGI = Clinical Global Impression severity scale; SDS= Sheehan Disability Scale; HAM-D= Hamilton Depression Scale; HAM-A= Hamilton Anxiety Scale