Table 4.

Impact of a heroin maintenance programme on heath related quality of life, measured by means of the SF-36 health survey, Geneva, 1995-6

Variable	Experimental group (n=27)				Control group (n=22)			P value§ for difference between groups
	Baseline	Follow up†	Effect size‡		Baseline	Follow up	Effect size‡
Physical functioning	71.1	79.6*	0.40		79.6	76.6	−0.14	0.13
Role-physical	33.3	59.3**	0.69		44.3	53.4	0.24	0.30
Bodily pain	56.4	71.1*	0.51		59.6	69.3	0.34	0.67
General health	42.2	53.7***	0.52		48.0	56.4	0.38	0.21
Vitality	31.7	47.6***	0.99		33.4	45.7*	0.76	0.26
Social functioning	40.3	64.4***	1.00		53.4	61.9	0.35	0.041
Role-emotional	18.5	63.0***	1.25		33.3	43.9	0.30	0.027
Mental health	36.0	54.4***	0.97		42.0	49.3	0.38	0.025

^†Significance of before comparisons between baseline and follow up denoted by ^*P<0.05, ^**P<0.01, ^***P<0.001. Wilcoxon matched pairs test (exact).  

^‡Difference divided by standard deviation at baseline.  

^§Mann-Whitney U test (exact).