Opioids for Back Pain Patients: Primary Care Prescribing Patterns and Use of Services

↵* Opioids delivered by pill, capsule, liquid, transdermal patch, and transmucosal administration were included. Opioids formulated for administration by injection or suppository were not included.

↵† Transmucosal fentanyl conversion to morphine equivalents assumes 50% bioavailability of transmucosal fentanyl, and 100-μg transmucosal fentanyl is equivalent to 12.5 to 15 mg of oral morphine.

↵‡ Transdermal fentanyl conversion to morphine equivalent is based on the assumption that one patch delivers the dispensed micrograms/hour over a 24-hour day and remains in place for 3 days.

Adapted from Von Korff M, Saunders K, Ray GT, et al. De facto long-term opioid therapy for noncancer pain. Clin J Pain 2008;24:521–7.¹⁹.

Values provided as n (%) unless otherwise indicated.

↵* Approximately 5% of patients had missing values for body mass index and smoking status; the percentages displayed are calculated for those cases that were not missing.

↵† “Acute” use was defined as use ≥90 days. “Episodic” use was defined as use >90 days but <120 days with fewer than 10 prescription fills. “Chronic” use was ≥120 days, or >90 days with ≥10 prescription fills.

↵‡ Generalized linear model F-test.

↵§ Cochrane-Armitage test for trend.

↵¶ Kruskal-Wallis test.

Values provided as odds ratios (95% CI).

↵* All models adjusted for age, gender, comorbidity score, and number of hospitalizations in the past year. The models for depression and for substance abuse also adjusted for the use of sedative-hypnotics.

↵† “Acute” was defined as use for ≥90 days. “Episodic” was defined as use for >90days but <120 days with fewer than 10 prescription fills. “Chronic” was defined as use for ≥120 days or >90 days with 10 or more prescription fills.

↵* ^aKruskal-Wallis test.

↵† Cochrane-Armitage test for trend.

↵‡ NA, not applicable. This category was not included in tests of statistical significance.