Predicting who develops chronic low back pain in primary care: a prospective study

To quantify the relative contribution of premorbid and episode specific factors in determining the long term persistence of disabling symptoms of low back pain.

Prospective cohort study.

Two general practices in the south Manchester area.

180 patients, who previously participated in a cross sectional population survey, who consulted because of low back pain during the study period. They were followed at 1 week and 3 and 12 months after consultation.

Persistent disabling low back pain in the 12 months after the consultation.

Disabling low back pain persisted in one third of participants after consultation and was more common with increasing age, among those with a history of low back pain, and in women. Persistence of symptoms was associated with "premorbid" factors (high levels of psychological distress (odds ratio 3.3; 95% confidence interval 1.5 to 7.2), poor self rated health (3.6; 1.9 to 6.8), low levels of physical activity (2.8; 1.4 to 5.6), smoking (2. 1; 1.0 to 4.3), dissatisfaction with employment (2.4; 1.3 to 4.5)) and factors related to the episode of low back pain (duration of symptoms, pain radiating to the leg (2.6; 1.3 to 5.1), widespread pain (6.4; 2.7 to 15), and restriction in spinal mobility). A multivariate model based on six factors identified groups whose likelihood of persistent symptoms ranged from 6% to 70%.

The presence of persistent low back pain is determined not only by clinical factors associated with pain but also by the premorbid state.