Opioid prescribing for cancer pain during the last 3 months of life: associated factors and 9-year trends in a nationwide United Kingdom cohort study.

PURPOSE: To determine time trends and characteristics associated with opioid analgesic prescribing to patients with cancer who are approaching the end of life. PATIENTS AND METHODS: This population-based cohort study used data on 29,825 patients diagnosed with five common cancers-lung (34.2%), colorectal (19.9%), female breast (21.6%), prostate (19.1%), and head and neck (5.2%)-in the United Kingdom General Practice Research Database (GPRD) who died between 2000 and 2008. Opioid prescription rates in the last 3 months of life were described. Characteristics associated with opioid prescribing were investigated by using generalized estimation equation models.
RESULTS: In the last 3 months of life, 43.6% (95% CI, 43.0% to 44.2%) of patients received at least one prescription of opioids: morphine (33.4%; 95% CI, 32.8% to 33.9%), diamorphine (11.6%; 95% CI, 11.2% to 11.9%), and fentanyl family (10.2%; 95% CI, 9.8% to 10.5%). Over time, prescription rates increased for opioids predominant during specific time periods, especially oxycodone. Older patients (age > 60 years) had significantly lower chances of receiving opioids than their younger (age < 50 years) peers (prevalence ratio [PR] range, 0.14 to 0.78), even adjusted for comorbidity. Women were slightly more likely than men to receive any type of opioid (PR,1.07; 95% CI, 1.04 to 1.11). Morphine and diamorphine (PR range, 1.14 to 1.56) were more commonly prescribed for lung and colorectal cancers and fentanyl family for head and neck cancers (PR, 1.39; 95% CI, 1.19 to 1.62) compared with for prostate cancers.
CONCLUSION: Morphine and diamorphine remain the stronghold for treating cancer pain in the United Kingdom. Opioid prescription rates are increasing over time. Prescription rates are lower for older people for all opioids, suggesting that this group needs attention.