Direct medical costs and medication compliance among fibromyalgia patients: duloxetine initiators vs. pregabalin initiators.

OBJECTIVES: To assess and compare direct medical costs and medication compliance between patients with fibromyalgia who initiated duloxetine and patients with fibromyalgia who initiated pregabalin in 2008. METHODS: A retrospective cohort study design was used based on a large US national commercial claims database (2006 to 2009). Patients with fibromyalgia aged 18 to 64 who initiated duloxetine or pregabalin in 2008 and who had continuous health insurance 1 year preceding and 1 year following the initiation were selected into duloxetine cohort or pregabalin cohort based on their initiated agent. Medication compliance was measured by total supply days, medication possession ratio (MPR), and proportion of patients with MPR ≥ 0.8. Direct medical costs were measured by annual costs per patient and compared between the cohorts in the year following the initiation. Propensity score stratification and bootstrapping methods were used to adjust for distribution bias, as well as cross-cohort differences in demographic, clinical and economic characteristics, and medication history prior to the initiation. RESULTS: Both the duloxetine (n = 3,033) and pregabalin (n = 4,838) cohorts had a mean initiation age around 49 years, 89% were women. During the postindex year, compared to the pregabalin cohort, the duloxetine cohort had higher totally annual supply days (273.5 vs. 176.6, P < 0.05), higher MPR (0.7 vs. 0.5, P < 0.05), and more patients with MPR ≥ 0.8 (45.1% vs. 29.4%, P < 0.05). Further, relative to pregabalin cohort, duloxetine cohort had lower inpatient costs ($2,994.9 vs. $4,949.6, P < 0.05), lower outpatient costs ($8,259.6 vs. $10,312.2, P < 0.05), similar medication costs ($5,214.6 vs. $5,290.8, P > 0.05), and lower total medical costs ($16,469.1 vs. $20,552.6, P < 0.05) in the postinitiation year. CONCLUSIONS: In a real-world setting, patients with fibromyalgia who initiated duloxetine in 2008 had better medication compliance and consumed less inpatient, outpatient, and total medical costs than those who initiated pregabalin.

The cost-effectiveness of duloxetine in chronic low back pain: a US private payer perspective.

OBJECTIVE: To assess the cost-effectiveness of duloxetine in the treatment of chronic low back pain (CLBP) from a US private payer perspective. METHODS: A cost-utility analysis was undertaken for duloxetine and seven oral post-first-line comparators, including nonsteroidal anti-inflammatory drugs (NSAIDs), weak and strong opioids, and an anticonvulsant. We created a Markov model on the basis of the National Institute for Health and Clinical Excellence model documented in its 2008 osteoarthritis clinical guidelines. Health states included treatment, death, and 12 states associated with serious adverse events (AEs). We estimated treatment-specific utilities by carrying out a meta-analysis of pain scores from CLBP clinical trials and developing a transfer-to-utility equation using duloxetine CLBP patient-level data. Probabilities of AEs were taken from the National Institute for Health and Clinical Excellence model or estimated from osteoarthritis clinical trials by using a novel maximum-likelihood simulation technique. Costs were gathered from Red Book, Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project database, the literature, and, for a limited number of inputs, expert opinion. The model performed one-way and probabilistic sensitivity analyses and generated incremental cost-effectiveness ratios (ICERs) and cost acceptability curves. RESULTS: The model estimated an ICER of $59,473 for duloxetine over naproxen. ICERs under $30,000 were estimated for duloxetine over non-NSAIDs, with duloxetine dominating all strong opioids. In subpopulations at a higher risk of NSAID-related AEs, the ICER over naproxen was $33,105 or lower. CONCLUSIONS: Duloxetine appears to be a cost-effective post-first-line treatment for CLBP compared with all but generic NSAIDs. In subpopulations at risk of NSAID-related AEs, it is particularly cost-effective.

Using daily interactive voice response assessments: to measure onset of symptom improvement with duloxetine.

Most clinical trials measure patient responses weekly, requiring patients to accurately recall and report their symptoms from the previous six days. More frequent assessments would be less susceptible to recall errors and recency effects as weekly assessments, but increased office visits burden clinicians and patients and can lead to higher attrition or non compliance. Interactive voice response (IVR) technology permits data collection at greater frequencies with minimal reporting burdens. An ancillary study within a randomized clinical trial evaluated the use of IVR to gather measures of patients' ratings of emotional and painful symptoms of depression on a daily basis. Unmedicated patients randomized to a starting dose of duloxetine of 30 mg QD (n=67) or 60 mg QD (n=70) called an IVR system daily to complete Verbal Numeric Scales for pain and Patient Global Impression of Improvement for both physical and emotional changes. Patients' compliance with daily IVR assessments was examined, and the IVR data obtained showed that patients started at 60 mg reported less pain and greater physical and emotional improvements than patients started at 30 mg. Dose related differences were evident as early as one day after the start treatment. This study provides new data about the usefulness of daily IVR assessments in clinical research and supports other studies regarding early symptom improvement with duloxetine.