The relation between pain intensity, disability, and the episodic nature of chronic and recurrent low back pain

Study Design. An observational study on the course of chronic and recurrent low back pain and its relation to disability and medication use performed on the basis of daily diary recording. Objectives. To provide a description of daily pain reporting by individuals with self-reported chronic and recurrent low back pain, to study how the i ntensity and episodic nature of low back pain is related to disability and medication use, and to classify subjects according to Von Korff's categorie s of chronic low back pain. Summary of Background Data. The natural history of low back pain has been d escribed, and some classification schemes have been proposed, but little ha s been reported on pain characteristics and their relation to self-report o f disability. Methods. Daily self-reports of pain intensity, social and work disability, and medication use were collected from 94 participants with self-reported c hronic or recurrent low back pain over a 6-month period. A metric for descr ibing the episodic nature of chronic low back pain was developed. Results. A significant effect of pain intensity on disability was found. Du ring an episode, participants had significantly greater disability and medi cation use. Work-related disability and medication use was significantly gr eater in the latter half of an episode. Conclusions. Pain intensity can affect disability, but the episodic nature of low back pain also affects the ability to function in both work and pers onal life. Intermittent increases in pain can markedly alter disability. Ch ronic low back pain should not be treated as a static phenomenon.