Comorbid insomnia in patients with chronic pain: a study based on the Swedish quality registry for pain rehabilitation (SQRP)

Purpose: This study investigates the prevalence of insomnia and its relationship to other symptoms and health aspects in patients with chronic pain. Methods: Patients with chronic pain conditions (n = 845) referred to a multidisciplinary pain centre completed surveys provided by the Swedish quality registry for pain rehabilitation (SQRP). The SQRP collects data on sociodemographics, health status, symptoms of pain, mood and insomnia and life satisfaction. Results: The majority of patients (65.3%) had clinical insomnia according to the insomnia severity index (ISI). Insomnia correlated significantly but weakly with pain, depression, anxiety and coping; the strongest multivariate correlations were found with depression and anxiety followed by pain interference and pain severity. Pain intensity, depression and anxiety correlated stronger than ISI with respect to the two investigated aspects of health. Conclusions: The prevalence of insomnia is high in patients with chronic pain conditions, but the level of importance in relation to other symptoms for health aspects is low, and the associations with other important symptoms are relatively weak. One way to increase the effects of multimodal rehabilitation programs may be to provide interventions directed specifically at insomnia rather than focusing only on interventions that address pain, depression and anxiety.