Table 3.

Kendall's tau-b correlations of PGI-I with VSSS-MT scores and opinion of methadone as a medication

	PGI-I
VSSS-MT, overall	-0.032
VSSS-MT, Basic interventions	-0.001
VSSS-MT, Specific interventions	-0.063
VSSS-MT, Social worker skills	-0.106
VSSS-MT, Psychologist skills	0.088
Opinion of methadone as a medication	-0.178*

VSSS-MT: Verona Service Satisfaction Scale for Methadone Treatment; PGI-I: Patient Global Impression of Improvement scale; *p < 0.05, two-tailed. The scores on the PGI-I scale are in descending order of improvement (1 = very much improved to 7 = very much worse) while both the VSSS-MT and the scores on the opinion on methadone as a medication are in increasing order of satisfaction (1 = terrible to 5 = excellent).