Opiate use is associated with elevated (acquisitive and non-acquisitive) offending.
The association between drug use and crime is stronger for women than men.
Cocaine use is associated with offending among males but not among females.
Opiate and cocaine use is associated with 25 times the rate of prostitution (females only).
To assess the relationship between testing positive for opiates and/or cocaine and prior offending.
139,925 persons (107,573 men) identified from a saliva test for opiate and cocaine metabolites following arrest in England and Wales, 1 April 2005–31 March 2009, were case-linked with 2-year recorded offending history. The prior offending rate, accounting for estimated incarceration periods, was calculated by: drug-test outcome; gender; four main crime categories (acquisitive, non-acquisitive, serious acquisitive, and non-serious acquisitive) and 16 sub-categories. Rate ratio (RR) compared opiate and/or cocaine positive to dual-negative testers. Adjusted rate ratio (aRR) controlled for age at drug test.
The relationship between testing positive for opiates and cocaine and prior 2-year offending was greater for women than men (aRR men 1.77; 95% CI: 1.75–1.79: women 3.51; 3.45–3.58). The association was weaker for those testing positive for opiates only (aRR: men: 1.66, 1.64–1.68; women 2.73, 2.66–2.80). Men testing positive for cocaine only had a lower rate of prior offending (aRR: 0.93, 0.92–0.94), women had a higher rate (aRR: 1.69, 1.64–1.74). The strongest associations were for non-serious acquisitive crimes (e.g. dually-positive: prostitution (women-only): aRR 24.9, 20.9–29.7; shoplifting: aRR men 4.05, 3.95–4.16; women 6.16, 5.92–6.41). Testing positive for opiates and cocaine was associated with violent offences among women (aRR: 1.54, 1.40–1.69) but not men (aRR: 0.98, 0.93–1.02).