Spontaneous onset of back pain

To assess the frequency with which patients attribute low back pain to spontaneous onset.

A consecutive sample of two distinct groups of patients seeking treatment for back pain: those without need to identify cause (study group, n = 4,689) and those required to report a specific event to qualify for benefits paid for by a third party (compensated group, n = 6,687).

Active exercise-based back pain rehabilitation clinics.

Research on the natural history of back pain has revealed frequent reports of spontaneous recovery, usually within 8-12 weeks after onset. There is little comparable literature pertaining to the report of spontaneous onset.

Data were collected for two groups of consecutive patients who attended for initial assessments of their back pain at 16 Canadian Back Institute locations, between May 1, 1994 and February 28, 1995. Patient responses were collected using a standardized, professionally administered questionnaire.

In the group without need to identify cause, 66.7% of patients could not identify an event producing their symptoms. For those required to report a specific event, only 9.8% of patients failed to attribute cause. Multivariate logistic regression revealed that the required-to-report group was approximately 15 times more likely to report an event (odds ratio = 14.95; 95% confidence interval = 13.44, 16.65) than the study group; those pursuing litigation were more than 2.5 times more likely to report a causative event (odds ratio = 2.68; 95% confidence interval = 2.09, 3.49).

Back pain occurred spontaneously in approximately 67% of patients seeking treatment in the study group. The authors consider spontaneous onset to be part of the natural history of back pain for this group.