Clinical course and prognostic factors in acute low back pain: patients consulting primary care for the first time.

STUDY DESIGN: Inception cohort study.

OBJECTIVES: To examine the clinical course of acute low back pain and to evaluate prognostic factors for nonrecovery.

SUMMARY OF BACKGROUND DATA: Few studies have explored clinical course and prognostic factors in patients who consult primary care for their first time because of an episode of low back pain of <3 weeks duration.

METHODS: A total of 123 patients with acute low back pain <3 weeks consulting primary care for the first time were included, and 120 completed 3 months follow-up. Baseline assessments included sociodemographic characteristics, back pain history and current status, psychological questionnaires and clinical examination. Main outcome measures were pain intensity, disability by Roland Morris Disability Questionnaire, and recovery of disability. Potential prognostic factors for recovery or not were analyzed by multivariate logistic regression.

RESULTS: At 4 weeks and 3 months 76% of the patients had recovered. Mean pain intensity and mean disability scores dropped 58% and 68%, respectively, of initial levels during the 3 months. The proportion with sickness absence was 8% at 4 weeks and 6% at 3 months. Several sociodemographic, clinical, and psychological factors were of prognostic value. Compared with their respective reference categories, age above 45 years (odds ratio 4.4, 95% confidence interval 1.4-14.0), smoking (3.0, 1.1-8.5), two or more neurological signs (4.6, 1.4-14.9), a score of >or=90 on the psychosocial screening (3.1, 1.0-9.4), and high levels of distress (4.1, 1.3-12.8) were the best prognostic factors of nonrecovery at 3 months.

CONCLUSION: During a period of 3 months, 24% of the patients had not recovered. Psychological factors and neurological signs were strongly associated with nonrecovery at 3 months. In addition to the traditional examination of neurological symptoms and signs, psychological factors should be considered already at the initial visit of an episode of low back pain.