Use of a modified version of the Opiate Treatment Index with amphetamine users: validation and pilot evaluation of a prescribing service

Abstract

There is a growing need to assess the efficacy of the treatment of amphetamine dependent clients. This study investigated the Opiate Treatment Index (OTI), a multidimensional instrument with six independent outcome variables, as a potentially appropriate tool. This was performed as part of a larger pilot investigation into the validation of the OTI with Welsh drug users at the Community Addictions Unit (CAU) in Cardiff, South Wales. To investigate the structure of the OTI with amphetamine users (n = 65) a factor analysis was undertaken, which demonstrated the utility of the instrument in this client group. Use of the OTI as a primary measure of treatment effect was assessed using a subsample of prescribed dexamphetamine users, through analysis of data obtained at two interviews, 6 months apart. The dexamphetamine prescribed subsample (n = 12), who were not new to treatment, showed a reduction in general health problems and stability for the other five outcome variables. It is suggested that the OTI can be used as part of a structured assessment procedure for amphetamine users. A number of possible strategies and protocols for this are discussed.