Predictors for completing an inpatient detoxification program among intravenous heroin users, methadone substituted and codeine substituted patients

Up to 1999 more opioid dependent patients in Germany were substituted with codeine or dihydrocodeine (summarised as codeine) than with methadone. The current retrospective study compares the differences in detoxification treatment outcome for codeine-substituted patients, methadone-substituted patients and patients injecting illicit heroin. The study is based on the medical records of 1070 patients admitted consecutively for opioid and polytox detoxification between 1991 and 1997. The main hypothesis was that injecting illicit-heroin users would complete detoxification treatment less often than codeine- or methadone- substituted patients, and that methadone-substituted patients who had received more structured treatment would complete more often than codeine-substituted patients who did not receive any structured treatment beyond the prescription of codeine. We analysed a number of demographic and drug related variables as possible predictors. Our bivariate analyses confirmed our main hypothesis: 50.4% (OR: 1.8) of the methadone-substituted patients, 45.5% (OR: 1.5) of the codeine-substituted patients and 35.9% (OR: 1 comparison group) of the injecting illicit-heroin users completed the detoxification program (P=0.006). This finding remained significant even after correcting for a number of confounders. Using stepwise multiple logistic regression analyses, we found age, education, history of imprisonment, regular contact with a counsellor, currently being on probation and reported plans for participating in an abstinence treatment program to be significant predictors of completing detoxification treatment. Although the current analysis did not rule out differences in pharmacological effects as a contributing factor, the results are consistent with an interpretation of a dose-response association between psychosocial/psychotherapeutic support and detoxification outcome. More psychosocial/psychotherapeutic support leads to better detoxification treatment response. (Author's abstract.)