Risk of death during and after opiate substitution treatment in primary care: prospective observational study in UK General Practice Research Database

To investigate the effect of opiate substitution treatment at the beginning and end of treatment and according to duration of treatment.Prospective cohort study. Setting UK General Practice Research Database.Primary care patients with a diagnosis of substance misuse prescribed methadone or buprenorphine during 1990-2005. 5577 patients with 267 003 prescriptions for opiate substitution treatment followed-up (17 732 years) until one year after the...