. 2014 Feb 11;9(2):e88379. doi: 10.1371/journal.pone.0088379

Table 3. Significant terms involving paternal age at birth in linear and linear mixed-effects models for endophenotype performance.

	Schizophrenia subjects only		Schizophrenia subjects and unaffected siblings combined
Endophenotype	Significant term^a (slope^b, P value^c ^, ^d, 95% CI)	R²	Significant term^a (slope^b, P value^d ^, ^e, 95% CI)	R²
CPT-IP 4-digit	Paternal age (slope = 0.19, P = 0.03, 95% CI = [0.01, 0.36])	0.11	Paternal age (slope = 0.20, P = 0.02, 95% CI = [0.03, 0.37])	0.41
Verbal memory	Paternal age by Multiplex status (Simplex slope = −0.07, 95% CI = [−0.42, 0.29]; Multiplex slope = −1.0, 95% CI = [−1.9, −0.15]; P for difference in slopes = 0.03)	0.13	Paternal age by Multiplex status (Simplex slope = −0.05, 95% CI = [−0.34, 0.25]; Multiplex slope = −0.89, 95% CI = [−1.5, −0.32]; P for difference in slopes = 0.005)	0.30
			Paternal age by Gender (Male slope = −0.05, 95% CI = [−0.34, 0.25]; Female slope = −0.43, 95% CI = [−0.83, −0.03]; P for difference in slopes = 0.049)

Abbreviations: CI, confidence interval; CPT-IP, Continuous Performance Test, Identical Pairs version.

Only terms involving paternal age at subject birth with an associated P value <0.05 are reported, and only endophenotypes with such terms are reported.

Slope and confidence intervals are in units of a 10-year increase in paternal age at birth. A positive slope indicates that subjects with older fathers perform better on the endophenotype.

P values are based on linear models with effects for paternal age, paternal age–by-gender, and paternal age–by–multiplex status, with subject age, test site, subject gender, and parental education as covariates.

After adjusting for multiple comparisons accounting for the 16 endophenotypes, none of the results are significant at an overall Type I error level of 5%.

P values are based on linear mixed-effects models with effects for paternal age, paternal age–by-gender, and paternal age–by–multiplex status, with group (proband versus sibling), subject age, test site, subject gender, parental education, and all second-order interactions involving group as covariates. Family membership served as a random effect to account for the relatedness of observations among family members.