To compare health care utilization of duloxetine initiators and pregabalin initiators among fibromyalgia patients in a real-world setting.
A retrospective cohort study was conducted based on a US national commercial health claims database (2006–2009). Fibromyalgia patients who initiated duloxetine or pregabalin in 2008, aged 18–64 years, and who maintained continuous health insurance coverage 1 year before and 1 year after initiation were assigned to duloxetine or pregabalin cohorts on the basis of their initiated agent. Patients who had pill coverage of the agents over the course of 90 days preceding the initiation were excluded. The two comparative cohorts were constructed using propensity score greedy match methods. Descriptive analysis and paired t-test were performed to compare health care utilization rates in the postinitiation year and the changes of these rates from the preinitiation year to the postinitiation year.
Both matched cohorts (n=1,265 pairs) had a similar mean initiation age (49–50 years), percentage of women (87%–88%), and prevalence of baseline comorbid conditions (neuropathic pain other than diabetic peripheral neuropathic pain, low back pain, cardiovascular disease, hypertension, headache or migraine, and osteoarthritis). In the preinitiation year, both cohorts had similar inpatient, outpatient, and medication utilization rates (inpatient, 15.7%–16.1%; outpatient, 100.0%; medication, 97.9%–98.7%). The utilization rates diverged in the postinitiation year, with the pregabalin cohort using more fibromyalgia-related inpatient care (3.2% versus 2.2%; P<0.05), any inpatient care (19.3% versus 16.8%; P<0.05), and fibromyalgia-related outpatient care (62.1% versus 51.8%; P<0.05). From the preinitiation period to the postinitiation period, the duloxetine cohort experienced decreases in certain utilization rates, whereas the pregabalin cohort had increases (percentage of patients with a fibromyalgia-related admission, −1.2% versus 0.4% [ P<0.01]; number of fibromyalgia-related outpatient claims, −1.7 versus 4.7 [ P<0.01]).
Fibromyalgia patients initiating pregabalin tended to consume more fibromyalgia-related inpatient and outpatient care in the first postinitiation year, whereas fibromyalgia patients initiating duloxetine tended to have lower utilization rates of fibromyalgia-related inpatient care in the postinitiation year than in the preinitiation year.