Pooling data from different populations: should there be regional differences in cerebral haemodynamics?

BMC Neurology

Table 6 ANCOVA and ANOVA results for comparison of cerebral haemodynamics parameters between geographical regions (stroke only)

	MS		F-statistic		p-Value
	ANCOVA	ANOVA	ANCOVA	ANOVA	ANCOVA	ANOVA
CBFv, cm.s⁻¹	3.2	8.6	0.7	0.9	0.83	0.42
CrCP, mm Hg	2.5	3.0	5.2	4.8	0.60	0.81
RAP, mmHg.s.cm^− 1	4.9	3.0	6.1	1.8	0.10	0.24
Coherence VLF range	5.7	9.2	3.2	4.5	0.31	0.19
Coherence LF range	3.8	4.4	2.9	4.3	0.44	0.31
Coherence HF range	3.1	5.3	2.3	3.6	0.56	0.29
Normalized gain VLF range, % mm Hg^− 1	14.0	5.1	5.2	1.4	0.07	0.33
Normalized gain LF range, % mm Hg⁻¹	8.1	4.5	0.9	2.3	0.30	0.12
Normalized gain HF range, % mm Hg⁻¹	7.8	4.4	5.5	1.2	0.21	0.40
Phase VLF range, radians	4.2	2.5	0.2	0.1	0.90	0.90
Phase LF range, radians	6.7	1.8	0.2	0.4	0.80	0.90
Phase HF range, radians	5.5	1.4	1.0	0.2	0.80	0.30
ARI	1.5	1.9	4.5	3.9	0.51	0.77

The analysis of covariance (ANCOVA) model included stroke aetiology and subtypes as covariates
ANOVA analysis of variance, MS mean square, AH affected hemisphere, UH unaffected hemisphere, VLF, LF, HF Very low, low and high frequency ranges, respectively
p-value for ANOVA (geographical interaction) and ANCOVA controlled for stroke aetiology and subtype

ISSN: 1471-2377