Table 1.

Final model (costs in £ sterling)

Variables	Dependent cost/ASTRO(97)-PU*
	Coefficient	t value
Constant	24.99	23.11
Need†:
psick	0.59	11.40
pnocare	0.03	2.17
pstudent	−0.23	−9.24
pbirths	1.88	17.57
Supply:
Dispensing practice	0.68	6.81
Not training status	0.32	4.02
No of general practitioners per patient	909.6	4.02
Single handed practice	−0.50	−4.59
General practice fundholding status	−1.15	−17.28
R2	0.41
Reset F(3, 8392)	0.24	P=0.86

^*Age, sex, and temporary resident originated prescribing units. 

^†For definitions see table 2.