Opioid use and healthcare costs among patients with DPNP initiating duloxetine versus other treatments

Abstract

Objective:

To compare opioid utilization and healthcare costs over a 1-year period following the initiation with duloxetine versus other standard of care (SOC) treatments among patients with diabetic peripheral neuropathic pain (DPNP).

Methods:

This retrospective cohort study assessed commercially-insured DPNP patients between 18 and 64 years old who initiated duloxetine or other SOC treatments (tricyclic antidepressants, venlafaxine, gabapentin, pregabalin) between 3/1/2005 and 12/31/2005. Initiation was defined as a 90-day period without available study medication. The first dispense date of the study medication was denoted as the index date. Selected patients had no opioid pill coverage during the 90 days prior to initiation. Duloxetine and SOC patients were matched via propensity scoring (1:1 ratio), controlling for demographics, comorbidities, prior healthcare utilization and costs, and prior medication history. Opioid utilization and healthcare costs over the 12-month post-index period were compared between study cohorts.

Results:

The matched sample included 117 patients in each of the duloxetine and SOC cohorts. Compared with SOC-treated patients, duloxetine-treated patients were less likely to use any opioids (52.1 vs. 84.6%, p < 0.05) over the 12-month post-index period. Duloxetine-treated patients, on average, had two fewer opioid prescriptions dispensed, 27 fewer days on opioids, 121 days greater delay in subsequent opioid use, and 1815 mg lower morphine equivalent dosage than SOC-treated patients (all p < 0.05). Also, duloxetine-treated patients had significantly lower total ($18 623 vs. 30 602, p < 0.05) and outpatient costs ($7371 vs. 15 343, p < 0.05).

Due to the use of a retrospective administrative claims database, limitations of this study include the potential for selection bias between study cohorts, and inability to measure unobservable confounding and disease severity and/or duration.

Conclusions:

Among commercially-insured DPNP patients, duloxetine-treated patients had delayed and reduced opioid use and lower healthcare costs than SOC-treated patients.

Key words::

• Diabetic peripheral neuropathic pain
• Duloxetine
• Healthcare costs
• Opioid utilization

Transparency

Declaration of funding

Funding of this project was provided by Eli Lilly and Company. The statements contained in this paper are solely those of the authors, and no endorsement by Lilly should be inferred.

Declaration of financial/other relationships

Y.Z. has disclosed that she is employed by, and owns stock in, Lilly. S.C., N.W., K.F. and L.B. have disclosed that they are employed by United BioSource Corporation. No financial conflicts are declared.

Acknowledgments

No assistance in the preparation of this article is declared.