Figure 1.

Cumulative re-presentation rates following drug free discharge (a) and drop out (b) from structured drug treatment service. Individuals presenting in each year of monitoring form each of the cohorts. Those discharged drug free (a) or dropping out (b) contribute to the cumulative re-presentation percentage in the first year they are seen again after leaving services. If they then leave services again they become part of a second cohort of discharge or drop out.