Table 2.

Aggregate excess relative risks (per Sv) of circulatory disease in published low/moderate dose (<5 Sv) epidemiological datasets with estimated average radiation dose to the heart/brain and for which quantitative risk assessment is possible (using as endpoint mortality from circulatory disease unless otherwise indicated)(reproduced in part from Little et al. 2009a)

Description	Studies included	ERR Sv−1 (95% CI)
All occupational and environmental studies including McGeoghegan et al. (2008) but excluding Muirhead et al. (2009)	Talbott et al. (2003)a, Ivanov et al. (2006), Kreuzer et al. (2006), Vrijheid et al. (2007), McGeoghegan et al.(2008)c, Azizova and Muirhead (2009)b	0.19 (0.14, 0.24)##
All occupational and environmental studies excluding McGeoghegan et al. (2008) but including Muirhead et al. (2009)	Talbott et al. (2003)a, Ivanov et al. (2006), Kreuzer et al. (2006), Vrijheid et al. (2007), Azizova and Muirhead (2009)b, Muirhead et al. (2009)	0.19 (0.14, 0.23)##
Atomic bomb survivor and medical irradiation studies	Darby et al. (1987)d, Davis et al. (1989), Preston et al. (2003)e, Yamada et al. (2004)f, Carr et al. (2005)g	0.03 (0.00, 0.07)#
All studies including McGeoghegan et al. (2008) but excluding Muirhead et al. (2009)	Darby et al. (1987)d, Davis et al. (1989), Preston et al. (2003)e, Talbott et al. (2003)a, Yamada et al. (2004)f, Carr et al. (2005)g, Ivanov et al. (2006), Kreuzer et al. (2006), Vrijheid et al. (2007), McGeoghegan et al.(2008)c, Azizova and Muirhead (2009)b	0.08 (0.06, 0.11)##
All studies excluding McGeoghegan et al. (2008) but including Muirhead et al. (2009)	Darby et al. (1987)d, Davis et al. (1989), Preston et al. (2003)e, Talbott et al. (2003)a, Yamada et al. (2004)f, Carr et al. (2005)g, Ivanov et al. (2006), Kreuzer et al. (2006), Vrijheid et al. (2007), Azizova and Muirhead (2009)b, Muirhead et al. (2009)	0.08 (0.05, 0.11)##

^aAnalysis based on heart disease (males and females separately)

^bAnalysis based on ischaemic heart disease and cerebrovascular disease morbidity, using external γ dose

^cAnalysis including underlying and contributory causes of death

^dAnalysis based on stroke and other circulatory disease (separately)

^eAnalysis based on heart disease and stroke (separately)

^fAnalysis based on morbidity from hypertension, hypertensive heart disease, ischaemic heart disease and stroke (separately)

^gAnalysis based on coronary heart disease and other heart disease, excluding highest dose group (3.1–7.6 Gy) (separately)

^#p value for heterogeneity p < 0.01

^##p value for heterogeneity p < 0.00000001