Objective: Duloxetine is indicated for treatment of major depressive disorders in the UK. While clinical trials have documented its clinical effectiveness, little is known regarding the relationship between duloxetine use and healthcare utilization in community practice. This study quantifies the impact of treatment with duloxetine on healthcare utilization among patients with depression and those with depression and co-existing pain.
Methods: Depressed adults initiating duloxetine during 1/1/2006-9/30/2007 were identified from the General Practice Research Database (GPRD). All-cause hospitalization, accident/emergency visits, specialist referrals, and analgesic use in the 12 months before (pre-period) and after (post-period) duloxetine initiation were compared. Generalized Estimating Equation models evaluated the pre-post change in the odds of hospitalization.
Results: Nine hundred and nine patients were identified, 413 had pre-period unexplained pain (UPain). Rates of hospitalization declined from the pre- to the post-period. Fewer UPain patients received analgesics post-duloxetine initiation. Multivariate analyses confirmed that the odds of hospitalization were lower after duloxetine initiation. UPain patients with pre-period anticonvulsant use had lower odds of hospitalization in the post-period and the reduction in odds was significantly larger than that of patients without pre-period anticonvulsants. While patients with pre-period anxiolytic use, alcohol/drug dependence, or sleep disorders did not show statistically significant pre-post change in the odds of hospitalization, these changes were significantly different from patients without these conditions.
Limitations: The study did not include a comparison group of patients who were non-users of duloxetine. Prevalence of chronic conditions might be under-estimated due to coding in the GPRD. Medications were assumed to be taken as prescribed. Study results are not generalizable beyond the population covered by the UK's primary care system.
Conclusions: All-cause hospitalization rates lowered among depressed patients and fewer UPain patients received analgesics post-duloxetine initiation. The reduction in the odds of hospitalization was most pronounced among UPain patients receiving pre-period anticonvulsants.