Caffeine and chronic back pain.

Abstract

Tobacco use and other behavioral factors are associated with chronic back pain. Anecdotes suggest excess caffeine use may also be associated with chronic back pain. We compared caffeine consumption by chronic back pain patients with caffeine consumption by controls. Retrospective case-control study. A multispecialty outpatient facility. Sixty new, consecutive patients with chronic back pain compared to 60 new, consecutive patients without chronic back pain. Patients were prospectively asked to complete an intake questionnaire. Daily caffeine consumption was estimated by analyzing the intake questionnaire. Differences between groups were analyzed by both normal and nonparametric statistics. Consumption of caffeine by patients with chronic back pain averaged 392.4 mg/day. Controls consumed 149.8 mg/ day, a significant difference (p = .0001). Men consumed 86% more caffeine per day than women (p = .02). Age and caffeine consumption showed little correlation (r = .126). Patients with chronic back pain consume over twice as much caffeine as patients without chronic back pain. Confounding variables and possible mechanisms associating caffeine with chronic back pain are discussed.