Table 3.

Multiple Linear Regression Analysis of the Effect of Possible Confounder Variables on the Level of Negative Symptoms at 1 Year

Variables	Coefficients	Confidence Intervals	P Value
Constant	19.2	14.0 to 24.3	.0000
Age in years	0.02	−0.06 to 0.1	.5780
Gender	−1.7	−3.3 to −0.08	.0390
Diagnosis (schizophrenia spectrum yes or no)	0.8	−0.9 to 2.5	.3560
DUP (log transformed)	0.09	−0.3 to 0.5	.6960
Years of education	−0.6	−1.0 to −0.3	.0000
Premorbid social functioning childhood	1.5	0.8 to 2.3	.0000
Premorbid social functioning change scores	0.9	0.3 to 1.5	.0020
ED reduction in DUP	−2.0	−3.6 to −0	.0150

Note: Model summary—R² = .242, adjusted R² = .214.