Recurrence of an Episode of Low Back Pain: An Inception Cohort Study in Emergency Departments.

OBJECTIVES

To (1) determine the 1-year estimate of recurrence of low back pain (LBP) in a cohort of people presenting to emergency departments who have recently recovered from an episode of acute LBP in a middle-income country, (2) estimate a recurrence of LBP stratified by the STarT Back Screening Tool (SBST), and (3) determine prognostic factors for the recurrence of LBP.

DESIGN

Prospective inception cohort study.

METHODS

We included 238 patients who presented to emergency departments with recent-onset nonspecific LBP in São Paulo, Brazil. The outcome was the recurrence of an episode of LBP, assessed using 2 definitions: (1) 12-month recall alone and (2) pain measurements at follow-up. Prognostic factors were determined by logistic regression.

RESULTS

Within 1 year, the estimated recurrence of an episode of LBP ranged from 35% (79/225 events) (first definition) to 44% (100/226 events) (second definition). When patients were stratified by the SBST, the estimate of recurrence ranged from 29% to 37% (21-27/73 events) for low-risk patients, from 33% to 39% (24-28/72 events) for medium-risk patients, and from 43% to 56% (34-45/80 events) for high-risk patients. Age, perceived risk of persistent LBP, and disability were independent prognostic factors associated with LBP recurrence within 1 year.

CONCLUSION

After recovering from a previous episode of acute LBP, 4 in every 10 patients experienced a recurrence within 1 year. This estimate varied depending on the classification used in the SBST. Within 1 year, age, perceived risk of persistent LBP, and baseline disability were predictors of recurrence. .