Abstract
Aim: The transtheoretical model is often used in substance abuse treatment planning. For polydrug abusing patients, operationalizing the stages of change is more difficult, as their readiness to change may differ depending on the substances. It was the aim of this study to investigate if the same structure of the Dutch Readiness to Change Questionnaire (RCQ-D) in a group of alcohol abusers could be found in an inpatient group of polydrug abusers for all substances.
Design: For each substance, the structure of RCQ-D was tested using factor-analysis. Internal consistency was evaluated with Cronbach's alpha. Mean scores were calculated to evaluate conformity with stage assignment. Around 305 polydrug abusers completed 1248 RCQ-D during their first week of stay.
Findings: The RCQ-D had a different, but interpretable structure from the expected one. A two-factor structure was found for alcohol, nicotine and opiates, a three-factor structure for benzodiazepines, cannabis, methadone and cocaine. The underlying construct, based on the transtheoretical model, seemed to fit for alcohol and nicotine. There were some problems of stage allocation for benzodiazepines, cannabis and methadone. But, people in action could be distinguished from those not in action. More serious problems of allocation were found for opiates and cocaine.
Conclusions: RCQ-D can be used to measure polydrug abusers’ thinking and use-behaviour separately by substance. The validity of RCQ-D to assign stages in case of opiates and cocaine is unclear.
