This study based used a practice-based, observational model to look at the effectiveness of intervention in a selected group of patients with both acute and chronic lower back pain (LBP). It compared the efficacy of chiropractic intervention with standard medical care in both types of LBP.
2780 patients were enrolled in the study over a 2-year period (1994 to 1996) from the practices of 60 DCs (1855 patients) and 111 MDs (925 patients) in 51 chiropractic and 14 general practice clinics. Patient data was obtained at the initial visit through a questionnaire administered in person, and the patients were followed up with 7 mailed questionnaires at regular intervals over a period of 4 years. Mailings were sent at 2 weeks, 1 month, 3 months, 6 months, and 1 year after the initial visit. In phase 2, patients were followed up at 24, 36, and 48 months.
Patients were eligible if LBP was their primary complaint, and was of mechanical origin; they were excluded if manipulation was contraindicated, or the back pain was of nonmechanical origin (such as from organic referred pain). Acute patients were those whose back pain was of less than 7 weeks duration; chronic back pain patients were those whose back pain was of 7 weeks duration or longer.
The physicians in the study delivered a variety of treatment methods. Chiropractic physicians gave care that included spinal manipulation, physical therapy, an exercise plan, and self-care education. Medical physicians gave care that included prescription drugs, an exercise plan, and self-care advice; roughly 25% of these patients were referred for physical therapy.
The primary outcomes measured were present pain severity, and functional disability, which were measured by questionnaires mailed to the patients at the above stated intervals.
The medical patients showed more severe baseline pain and disability when entering treatment, greater prevalence of pain radiating below the knee, and poorer general health status, than in patients treated by chiropractors. These differences were more pronounced in the chronic patients than in the acute patients.
A modest advantage was seen for DC care when compared with MD care in pain relief for the first 12 months. This difference was very small for acute LBP, but was greater for those with chronic LBP during the first year of treatment. There were no differences for patients cared for between 12 and 24 months. Trends in disability were similar to the pain trends, but were of smaller magnitude.
There was an advantage chiropractic care in chronic patients with pain radiating below the knee, and some small advantages were also seen in the acute patient group. Differences were also seen in chronic patients with no leg pain during the first 3 months of care. There were no differences in the 2 groups and the 2 types of medical care for pain radiating above the knee.
All patient groups saw clinically significant improvement in pain and disability over the course of treatment. Acute patients saw greater improvement, with many obtaining near complete relief of their symptoms. Most achieved symptom relief by 3 months, followed by a plateau through 12 months. This was followed by significant, clinical aggravation of pain at 12 to 24 months, with another plateau until 4 years. Little increase in disability was seen between 12 and 48 months.
Of note, at 3 years into the study, 45% to 75% of patients noted at least 30 days of pain during the previous year, even in those who had gained significant pain and disability relief through early intervention. 19% to 27% of chronic LBP patients noted daily pain during the previous year.
Haas M, Goldberg B, Aickin M, Ganger B, Attwood M. A practice-based study of patients with acute and chronic low back pain attending primary care and chiropractic physicians: two-week to 48-month follow-up. Journal of Manipulative and Physiological Therapeutics 2004;27(3):160-169.