Table 8.

Comparing brain volumes while controlling for additional covariates

Comparison	Additional covariates	Estimate (%)	CI low	CI high	p
Group 2 vs 1		−0.0041	−0.0061	−0.0021	0.0000
Group 2 vs 1	BMI	−0.0047	−0.0071	−0.0022	0.003
Group 2 vs 1	Depression	−0.0048	−0.0076	−0.0020	0.007
Group 2 vs 1	Income and education	−0.0065	−0.0094	−0.0035	0.0000
Group 3 vs 4		−0.0012	−0.0028	0.0004	0.13
Group 3 vs 4	BMI	−0.0005	−0.0018	0.0008	0.43
Group 3 vs 4	Depression	−0.0004	−0.0018	0.0010	0.56
Group 3 vs 4	Income and education	0.0001	−0.0012	0.0015	0.84

“Group 2: Short sleep and sleep problems/sleepiness” compared with “group 1: Short sleep and no sleep problems/sleepiness.” Estimated differences in regional brain volumes were combined using meta-analysis.