Insomnia Increases Symptom Severity and Health Care Utilization in Patients with Fibromyalgia: A Population-based Study

Objective:This study aimed to determine whether comorbid insomnia is associated with increased use of fibromyalgia-related medications and health resources in fibromyalgia (FM) patients.Materials and Methods:We analyzed data retrieved from the Longitudinal Health Insurance Database 2010, which contains claims data of 1 million beneficiaries randomly selected from Taiwan's National Health Insurance program. Patients treated for FM (n=17,920) on 2 separate visits between 2000 and 2001 were selected and subsequently divided into 2 groups: patients with and without comorbid insomnia (n=5466 and 12,454, respectively). Insomnia was identified through diagnosis on 2 separate visits after the index FM date. FM-related pharmacotherapies and ambulatory care visits were tracked from the index date to the end of 2013.Results:Insomnia was associated with increased likelihood of future use of antidepressants (adjusted odds ratio [OR]=3.84, P<0.001), gabapentin (adjusted OR=1.67, P<0.001), pregabalin (adjusted OR=1.79, P=0.046), muscle relaxants (adjusted OR=3.05, P<0.001), and opioids and tramadol (adjusted OR=1.59, P<0.001) among FM patients compared with FM patients without insomnia. In addition, a diagnosis of insomnia was associated with an increased frequency of visits to ambulatory care services for both FM (β=1.79; 95% confidence interval, 1.57-2.02; P<0.001) and other conditions (β=108.51; 95% confidence interval, 103.14-113.89; P<0.001).Discussion:This study demonstrates the substantial burden of comorbid insomnia in patients with FM.