Pharmacoepidemiology of chronic noncancer pain patients requiring chronic opioid therapy: A nationwide population-based study

Abstract

Objective: This study was aimed to explore the pharmacoepidemiology of chronic noncancer pain (CNCP) patients who required chronic opioid therapy (COT) in the Taiwanese population.

Methods: Using the Taiwan National Health Insurance Research Database during 2008-2009, COT-requiring CNCP patients were identified by the inclusion criteria of both chronic analgesic requirement for >3 months per year and long-term use of controlled opioids for >28 therapeutic days during any 3-month period in ambulatory visits with malignancy-related pain excluded. Their demographic data and pharmacoepidemiological characteristics of opioid consumption and opioid prescriptions issued in ambulatory visits were analyzed.

Results: In total, 159 patients were enrolled as COT-requiring CNCP patients, and the prevalence was calculated at 0.016% in a 2-year period. Females were outnumbered by males (45.3% vs. 54.7%). Almost 60% of them were of working age and 93.7% belonged to low-income households, as in the health insurance claims, probably implying socioeconomic disadvantages associated with CNCP. The leading three diagnoses were unspecified myalgia and myositis, lumbago, and abdominal pain of unspecified site. The most common department from where these 159 CNCP patients obtained their opioid prescriptions was the emergency department (27.6%), ensued by a pain clinic (25.3%), but they could acquire only a few opioid therapeutic days through emergency department visits. Moreover, pain clinic satisfied the majority of opioid therapeutic days. Among all opioids, morphine was the most frequently prescribed in opioid-obtaining ambulatory visits, accounting for most of the opioid therapeutic days as well as opioid consumption.

Conclusion: COT-requiring CNCP patients were easily associated with adverse socioeconomic liabilities and often visited emergency department as well as pain clinics. Morphine was the main opioid used for their chronic pain. Transfer of COT-requiring CNCP patients to appropriate departments is strongly recommended for efficient long-term pharmacotherapy for their chronic pain.

Keywords: chronic noncancer pain; chronic opioid therapy; opioid therapeutic days.