Prevalence and Characterization of Breakthrough Pain Associated with Chronic Low Back Pain in the South of Spain: A Cross-Sectional, Multicenter, Observational Study.

Chronic low back pain (CLBP) is highly prevalent in industrialized countries, where it is one of the main causes of disability. Patients with CLBP in treatment with opioids often experience episodes of breakthrough pain (BTP), but data on prevalence and treatment preferences are scarce. The objectives of this study were, first, the evaluation of the prevalence of BTP in patients with CLBP in the South of Spain (N = 1,868) and, second, the characterization of BTP in these patients (N = 295). Data was collected on presence of BTP, type and location of pain, treatment, compliance, and patient satisfaction. We found a prevalence of BTP in patients with CLBP of 37.5% (95% CI: 35.3%-39.7%), similar in men and women. 75% of the patients were older than 50 years. The preferred drug of patients who control BTP with opioids is fentanyl (78.3%) and its most common form of administration is nasal (53.2%). Therapeutic compliance was high and 46.3% of patients considered the control of their BTP very satisfactory. Our study showed that BTP is common in patients with CLBP and that current treatments seem adequate.