Beyond the good prognosis. Examination of an inception cohort of patients with chronic low back pain

Abstract

Study design: A 22-month prospective cohort study.

Objectives: To describe the course of an inception cohort of patients with chronic low back pain.

Summary of background data: Chronic low back pain is a debilitating condition with great medical and social cost.

Methods: A cohort of 1246 patients with acute low back pain who sought treatment from 208 North Carolina providers was observed. Patients who developed chronic low back pain were identified. Entry criteria were back pain of less than 10 weeks' duration, no previous care for this episode of low back pain, no previous spine surgery, not pregnant, no nonskin malignancy, and access to a telephone. The providers were of four types: primary care medical doctors, doctors of Chiropractic, orthopedic surgeons, and health maintenance organization-based primary care providers. Patients were contacted by telephone shortly after enrollment and at 2, 4, 8, 12, and 24 weeks, with a final interview at 22 months. Patient functional status, care-seeking, and satisfaction were evaluated.

Results: Ninety-six patients had chronic, continuous symptoms for 3 months, forming the inception cohort of chronic low back pain. A valid, reliable measure of back-specific functional disability also was used. Predictors of the development of chronicity were poor baseline functional status and sciatica. A more powerful predictor of chronicity was poor functional status at 4 weeks. Two thirds of patients with chronic low back pain at 3 months had functionally disabling symptoms at 22 months, and a majority of these were employed. Satisfaction with care was low. Forty-six patients (2.6% of the entire cohort) underwent surgery, with no statistically significant difference in surgical rates among initial provider strata. Patients who underwent surgery after 3 months had a Roland disability score at 22 months of 10 (7.7, 12.3). Forty-one percent of patients with chronic low back pain see an orthopedic or neurologic surgeon. Chronic low back pain occurs in 7.7% of patients who seek care for acute low back pain, with unremitting pain for 22 months in 4.7%.

Conclusion: Once established, chronic low back pain is persistent. Most patients with chronic low back pain seek little care, and a majority are employed. Future research should emphasize maintenance of employment and function.