Internal consistency of items = .74 (Alpha reliability coefficient) derived from scores of 243 clients (mostly methadone maintained) from the Royal Free Drug Service in London.

Total score test-retest reliability = .83 (Pearson correlation), .82 (Intra-class correlation) derived from 60 stabilised methadone maintained clients, mean retest interval 53.8 days (sd = 12.1).

Total score inter-rater reliability = .84 (Pearson correlation), .82 (Intra-class correlation) derived from 20 stabilised methadone maintained clients, mean retest interval 45.1 days (sd = 28.2).

Total score inter-rater reliability = .91 (Pearson correlation), .91 (Intra-class correlation) derived from 20 consecutive intake referrals at CORE trust, an abstinence oriented day centre, retests performed on same day.

Opiate Treatment Index (OTI) sub-scale correlations with corresponding CISS items and CISS total score

Correlations with other psychological measures, corresponding CISS item and CISS total score

A CISS cut-off score of 6 or less can be used to indicate "good outcome" for abstinence based treatment.

This correctly identified 88% of six-month outcomes where drug use was assessed only in the month before follow-up.

This correctly identified 84% of outcomes where drug use was assessed over the entire six-month follow-up period.

Christo, G. (1998). Outcomes of residential care placements for people with drug and alcohol problems. The Centre for Research on Drugs and Health Behaviour.

Christo, G., Spurrell, S. and Alcorn, R. (2000). Validation of the Christo Inventory for Substance-misuse Services (CISS): a simple outcome evaluation tool. Drug and Alcohol Dependence.

Darke, S., Hall, W., Wodak, A., Heather, N. and Ward, J. (1992). Development and validation of a multi-dimensional instrument for assessing outcome of treatment among opiate users: the Opiate Treatment Index. British Journal of Addiction, 87, 733-742.

Rosenberg, M. (1965). Society and the adolescent self-image. Princeton University Press, Princeton N.J..

Sobell, L.C., Sobell, M.B., Leo, G.I. and Caneilla, A. (1988). Reliability of a timeline method: assessing normal drinkers' reports of recent drinking and a comparative evaluation across several populations. British Journal of Addiction, 83, 393-402.

Spielberger, C.D. (1988). State-Trait Anger Expression Inventory: research edition professional manual. Psychological Assessment Resources Inc., Florida.

Spielberger, C.D., Gorusch, R.L., Lushene, R. and Jacobs, G.A. (1984). Manual for the State-Trait Anxiety Inventory (form Y). Consulting Psychologists Press, California.

Spielberger, C.D., Jacobs, G., Russell, S. and Crane, R.S. (1983). Assessment of anger: the State-Trait Anger Scale. In Advances in personality assessment (vol. 2, pp 159-187), Butcher, J.N. and Spielberger, C.D.. Erlbaum, Hillsdale N.J..