Background: Recent concern about drug use has focused attention on the illegal income generated by users.
Aims: To investigate factors associated with drugs expenditure and to estimate the cost of illegal acquisitions used to pay for drugs.
Method: We collected self-report data from 954 current injectors, interviewed at multiple street, needle/syringe exchange and drug treatment sites throughout Glasgow.
Results: Injectors' mean weekly drug spending was 324 Pounds. The mean annual illegal drugs spend was estimated to be 11,000 Pounds per injector. We provide a central estimate--194 million Pounds per annum--of the retail value of goods acquired illegally by injectors in Glasgow in order to pay for drugs. Higher drug spends were associated with having been imprisoned more often and with those reporting acquisitive crime, drug dealing and prostitution. Treatment with methadone, among individuals who injected in the previous two months, was associated with a 20% reduction in a typical spend on drugs.
Conclusions: Treatment effectiveness needs to be measured both in terms of health benefit and in terms of reduction in drugs expenditure and recidivism.