According to the analysis plan (see paragraph 3.3), the effects of discontinuing the experimental treatment with co-prescribed heroin after 12 months were investigated by determining the percentage responders in the 12 months co-prescribed heroin condition who had subsequently deteriorated considerably - i.e. at least 20% of the baseline value on at least one of the outcome domains on which the patient had responded - two months after termination of the heroin treatment. This analysis was conducted only for treatment completers who were responders at the month 12 assessment.

From the 76 patients in the intention-to-treat population in the co-prescribed heroin group, 55 patients completed the experimental treatment period (see chapter 5A). Among this subgroup of treatment completers, 32 patients were responders (58.2%). Among these responders, the percentage of patients, who had deteriorated two months after discontinuing the co-prescribed heroin treatment, amounted to 84.4%.

The clinical meaning of the observed rate of deterioration is illustrated in Table 11, which shows the changes in mean scores from month 12 to month 14 on the scales and items used as components of the primary outcome measure in the trial, among the deteriorated responders (n=27).

Table 11. Changes in patient status from month 12 to month 14 (mean scores; n = 27)

As can be seen in Table 11, marked changes occurred from month 12 to month 14 on most variables. The mean MAP-HSS score increased from month 12 to month 14 from 4.3 to 13.2, and the mean SCL-90 total score from 30.6 to 62.1. The mean number of days of illegal activities in the month prior to the assessment increased from less than one day to 16 days. In addition, increases were observed for the number of days without contact with a non-drug-using person, and for the number of days of cocaine use in the previous month. On all variables, the changes from month 12 to month 14 indicate a return to the baseline values observed at the start of the trial.