"It has emerged that heroin-assisted treatment is a suitable option only for a small proportion (currently 4%) of the 30,000 severely dependent injecting drug users. Heroin-assisted treatment is not a replacement for other substitution or abstinence-based therapies, but an important addition for those drug users that have so far fallen through the therapeutic net. This is confirmed by the relatively modest increase in patient numbers since the bar on the legally permitted maximum number was lifted."
Heroin-Assisted Treatment (HeGeBe) in 2000. Swiss Federal Office of Public Health. Bern, Switzerland: SFOPH, August 28, 2001.