The substances and choices scale (SACS)--the development and testing of a new alcohol and other drug screening and outcome measurement instrument for young people.

Aims: To describe the development and evaluation of the Substances and Choices Scale (SACS), an adolescent alcohol and other drug (AOD) self-report instrument designed in a similar format to the Strengths and Difficulties Questionnaire (SDQ).

Design: A literature review, extensive consultation and discriminant analysis on a pilot sample (n = 61) of adolescents informed the development of the SACS. The psychometric properties of the SACS were then tested in a larger community and clinical sample.

Setting: Three youth out-patient AOD treatment services and three secondary schools in Auckland, New Zealand.

Participants: 13-18-year-old males and females attending the services (n = 120) or schools (n = 531).

Measurements: The SACS was administered with the CRAFFT, the Problem Oriented Screening Instrument for Teenagers (POSIT) and the Strengths and Difficulties Questionnaire (SDQ).

Findings: Reliability of the SACS was sound, with coefficient alpha 0.91 and 3-week test-retest correlation 0.88. Congruent validity coefficients of the SACS versus the CRAFFT and the POSIT were 0.79 and 0.91, respectively. A ROC curve demonstrated the SACS as having a predictive value of 92%. Repeat SACS scores in a treatment sample indicated that the SACS had utility in measuring change. Feedback from participants indicated that the SACS was highly acceptable.

Conclusions: The SACS is a simple AOD instrument that is reliable, valid and acceptable to young people. It has utility in screening and measuring outcome and should enhance the identification and treatment of AOD difficulties in adolescents across a range of health settings.