Opioid use and survival at the end of life: a survey of a hospice population.

Concern that opioids hasten death may be among the reasons that pain is treated inadequately in populations with advanced illness. Studies that assess the true risks are needed. To determine whether survival after last opioid dose change is associated with opioid dosing characteristics and other factors, data from the National Hospice Outcomes Project, a large prospective cohort study involving 13 U.S. hospice programs, were analyzed. Of 1,306 patients, 725 received opioids and underwent at least one dose change before death. Subsamples based on maximum opioid dose compared patients receiving usual doses with those receiving high-dose therapy. Spearman rank correlations examined bivariate associations between survival after final dose change and other variables, including dose in morphine equivalent mg and percentage dose increase. Multivariate least squares regression analyses determined associations between survival and other variables, including those significant in bivariate analyses. The mean+/-SD number of days between final dose change and death was 12.46+/-23.11. Multivariate models demonstrated a significant association between shorter survival and higher opioid dose, a cancer diagnosis, unresponsiveness, and pain of <5 on a 0-10 scale, but none of these models explained >10% of the variance in time till death. Analyses of subsamples did not reveal additional effects of dose. This analysis revealed that opioid dosing was associated with time till death, but this factor would explain very little of the variation in survival. In a hospice population, survival is influenced by complex factors, many of which may not be measurable. Based on these findings, concern about hastening death does not justify withholding opioid therapy.