The risk of all-cause mortality is high among long-term opioid users with chronic pain, and opioid use increases the risk of injuries and toxicity/poisoning.
This study aimed to investigate the risk of death, development of cancer, and hospital inpatient admissions resulting from injuries and toxicity/poisoning among opioid users with chronic noncancer pain. A population-based cohort of 13,127 adults, who have participated in the Danish Health Interview Surveys in 2000 or 2005 and have been followed up prospectively by registers until the end of 2011, were classified according to the absence or presence of chronic pain (ie, pain lasting ≥6 months) and long-term or short-term opioid use (individuals using at least 1 prescription per month for 6 months in the previous year and at least 1 prescription in the previous year, respectively). The risk of all-cause mortality was 1.72 (95% confidence interval [CI] = 1.23–2.41) times higher among long-term opioid users than among individuals without chronic pain. The risk of death was lower, but still significantly higher in short-term (1.36, 95% CI = 1.07–1.72) and non-opioid users with chronic pain (1.39, 95% CI = 1.22–1.59) than in the background population. There was no statistically significant association between long-term opioid use and cardiovascular and cancer mortality. No deaths among opioid users were caused by accidents or suicides, although opioid users had higher risks of injuries and toxicity/poisoning resulting in hospital inpatient admissions than individuals without chronic pain. The risk of all-cause mortality was significantly higher among long-term opioid users, but no obvious associations between long-term opioid use and cause-specific mortality were observed. However, opioid use increased the risk of injuries and toxicity/poisoning resulting in hospital inpatient admissions.
aNational Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
bMultidisciplinary Pain Centre, Department of Neuroanaesthesiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark
cSection of Palliative Medicine, Department of Oncology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark
dDepartment of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen, Copenhagen, Denmark
*Corresponding author at: Section of Palliative Medicine, Department 4111 – Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark. Tel.: +45 35454797; fax: +45 3545 7157.
Article history: Received May 20, 2014; Received in revised form June 30, 2014; Accepted July 3, 2014.
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.