Study	Intervention	Outcome	Int pre (%)	C pre (%)	Int post n/N (%)	C post n/N (%)	Relative % change (post)	Int vs C absolute change from pre (%)	ARD	Absolute % change (post)	P value
Dey 2004	Ed mat + EO + organisational	Number referred for x‐ray	(20.4)	(21.1)	158/1049 (15.1)	156/1138 (13.7)	10.2	5.3 vs 7.4	‐2.1	‐1.4	NS
Oakeshott 1994	Ed mat	X‐ray requests (by practice) conforming to guidelines (spine)	(39.5)	(34.7)	(44.8)*	(33.5)*	33.7	5.3 vs ‐1.2	6.5	11.3	NS
Rossignol 2000	Organisational**	Number received imaging test (x‐ray) 3 months	(61.1)	(53.6)	7/47 (14.9)	14/48 (29.2)	49.0	46.2 vs ‐24.4	21.8	14.3	NS
		Number received imaging test (MRI, CT, mylogram) at 3 months	(22.0)	(23.2)	6/47 (12.8)	19/48 (39.6)	67.7	9.2 vs ‐16.4	25.6	26.8	<0.01
		Number received imaging test (x‐ray) 3 to 6 months	(61.1)	(53.6)	4/44 (9.1)	6/45 (13.3)	31.6	52.0 vs 40.3	11.7	4.2	NS
		Number received imaging test (MRI, CT, mylogram) 3 to 6 months	(22.0)	(23.2)	6/44 (13.6)	6/45 (13.3)	2.3	8.4 vs 9.9	1.5	‐0.3	NS
					Median effect size from Rossignol 2000					9.3