Opioid-Related Death in Patients with Nonmalignant Pain
To assess the association between opioid dose and opioid-related death in patients with nonmalignant pain, researchers used administrative and pharmacy records to conduct a case-control study of 607,156 patients aged 15 to 64 years who received a prescription opioid between 1997 and 2006. Cases were opioid-related deaths as determined by a coroner. Controls were matched to cases based on age, gender, receipt of opioids during the year of the index date (date of case’s death), comorbidity, and disease-risk index results. For cases and controls, the average daily opioid dose at the index date was calculated and converted into morphine equivalents in milligrams (mg). Four hundred ninety-eight opioid-related deaths and 1714 patients met criteria for inclusion as cases and controls, respectively.
- The average age of cases at the time of death was 43 years. The majority of deaths were accidental.
- Compared with controls, cases were more likely to have received psychotropic drugs, methadone, benzodiazepines, and antidepressants; to have used multiple physicians or pharmacies for opioid prescriptions; and to have current or past alcohol dependence.
- In analyses controlling for confounders, when compared with a reference of <20 mg morphine equivalents, increasing daily opioid dose was associated with greater risk of opioid-related death:
- 20–49 mg (odds ratio [OR], 1.3).
- 50–99 mg (OR, 1.9).
- 100–199 mg (OR, 2.0).
- >200 mg (OR, 2.9).