Table 4 Coefficients for the constant variance [\(\beta\) (95% confidence interval)] and complex level-1 models [\({\sigma }^{2}\) (95% confidence interval] of exposure to childhood trauma as assessed by continuous score on the CTQ (Childhood Trauma Questionnaire) regressed on individual tests of neurocognitive performance, controlling for covariates.

From: Patterning of individual variability in neurocognitive health among South African women exposed to childhood maltreatment

	Homogeneous variance		Heterogeneous variance			LRT p
	\(\beta\)(95% CI)	p	\({\sigma }^{2}\) (95% CI) (intercept)	Covariance	\({\sigma }^{2}\) (95% CI) (exposure)	p
Verbal episodic memory
HVLT-L	− 0.01 (− 0.03, 0.02)	0.783	17.06 (13.83, 20.28)	0.05 (− 0.03, 0.14)	− 0.01 (− 0.01, 0.01)	0.604
HVLT-DR	− 0.01 (− 0.02, 0.01)	0.351	4.44 (3.49, 5.39)	0.01 (− 0.01, 0.03)	− 0.01 (− 0.01, 0.01)	0.740
Visual episodic memory
BVMT-L	0.01 (− 0.05, 0.05)	0.966	42.36 (31.78, 52.96)	− 0.05 (− 0.35, 0.24)	0.02 (− 0.01, 0.05)	0.250
BVMT-DR	− 0.01 (− 0.03, 0.02)	0.639	7.57 (5.71, 9.43)	− 0.01 (− 0.05, 0.05)	0.01 (− 0.01, 0.01)	0.393
Information processing speed
WAIS DS	− 0.13 (− 0.23, − 0.04)	0.004	134.59 (102.61, 166.56)	− 0.25 (− 1.12, 0.63)	0.04 (− 0.03, 0.12)	0.261
WAIS SS	− 0.02 (− 0.06, 0.04)	0.711	50.21 (39.18, 61.26)	− 0.11 (− 0.42, 0.19)	0.01 (− 0.02, 0.03)	0.701
TMT-A	0.14 (− 0.03, 0.30)	0.110	525.16 (407.49, 642.83)	3.38 (0.64, 6.12)	− 0.08 (− 0.30, 0.133)	0.063
Color Trails 1	− 0.09 (− 0.24, 0.07)	0.275	527.35 (422.92, 631.77)	0.70 (− 2.07, 3.47)	− 0.08 (− 0.23, 0.08)	0.739
Stroop Word	− 0.18 (− 0.30, − 0.05)	0.004	266.26 (206.69, 325.84)	− 0.05 (− 1.63, 1.53)	0.02 (− 0.10, 0.14)	0.942
Stroop Color	− 0.14 (− 0.24, − 0.05)	0.003	156.15 (119.13, 193.17)	0.08 (− 0.90, 1.05)	0.03 (− 0.05, 0.18)	0.419
Executive functions
Color Trails 2	0.17 (− 0.17, 0.51)	0.329	2001.95 (1666.32, 2337.58)	13.36 (3.19, 23.53)	n/a*	0.005
WCST-64	− 0.03 (− 0.13, 0.06)	0.493	123.57 (93.29, 153.85)	− 0.71 (− 1.61, 0.18)	0.08 (0.01, 0.16)	0.262
Category	0.01 (− 0.15, 0.17)	0.922	665.72 (540.63, 790.81)	1.65 (− 1.66, 4.97)	− 0.15 (− 0.31, − 0.01)	0.274
Stroop-CW	− 0.04 (− 0.12, 0.03)	0.260	84.51 (63.22, 105.81)	0.34 (− 0.20, 0.88)	0.03 (− 0.02, 0.08)	0.049
Verbal fluency
COWAT	0.01 (− 0.06, 0.07)	0.911	79.38 (62.41, 96.36)	− 0.23 (− 0.71, 0.24)	0.01 (− 0.02, 0.04)	0.594
Animals	− 0.01 (− 0.04, 0.01)	0.183	8.29 (6.46, 10.13)	− 0.02 (− 0.07, 0.03)	0.01 (− 0.01, 0.01)	0.745
Action	− 0.01 (− 0.03, 0.03)	0.989	14.09 (11.18, 17.00)	0.03 (− 0.04, 0.11)	− 0.01 (− 0.01, 0.01)	0.741
Working memory
PASAT 50	0.01 (− 0.05, 0.07)	0.795	80.39 (63.95, 96.83)	− 0.51 (− 0.99, − 0.02)	0.01 (− 0.02, 0.04)	0.126
WMS-III SS	0.01 (− 0.02, 0.02)	0.824	10.00 (7.91, 12.09)	0.05 (0.01, 0.10)	− 0.01 (− 0.01, − 0.01)	0.184

Log-likelihood ratio test (LRT) values comparing the variance estimates from OLS models with complex level-1 models are reported in the last column.
All models adjusted for age, education level, HIV status, marital status, employment status, income, depression and PTSD symptoms levels.
Mean and variance estimates that lie between − 0.01 and 0.01 were rounded to the closer of the either values. The rounding does not influence the inference as these estimates were not noticeably different from zero.
Some variance estimates were allowed to be negative, which is intuitively confusing. However, these estimates should be interpreted as part of a variance function, which is non-negative.
LRT loglikelihood ratio test, WCST Wisconsin Card Sorting Test, Stroop-CW Stroop Color-Word Incongruence, TMT-A Trail Making Test, Version A, WAIS-III DS WAIS-III Digit Symbol, WAIS-III S–S WAIS-III Symbol Search, HVLT-R, L Hopkins Verbal Learning Test, Revised, Learning, HVLT-R, DR Hopkins Verbal Learning Test, Revised, Delayed Recall, BVMT-R, L Brief Visuospatial Memory Test, Revised, Learning, BVMT-R, DR Brief Visuospatial Memory Test, Revised, Delayed Recall, PASAT Paced Auditory Serial Addition Task, WMS-III SS WMS-III Spatial Span.
*n/a is entered here because the quadratic function did not converge. Therefore we ran a linear function.

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