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.

• Early intervention reduces chronic pain. Those who received early intervention for acute lower back pain, at 3 years after the initial injury, reported fewer days of back pain than those who waited longer for intervention. This would support providing early intervention for patients with acute back pain, since outcomes were better than in those who delayed treatment.
• Chiropractic is beneficial for certain kinds of pain. Chiropractic care was more effective than standard medical care in certain situations: during the first 12 months in patients with chronic lower back pain, and for the treatment of LBP with pain radiating below the knee. The majority of the relief was obtained during the first 3 months of treatment, and was sustained throughout the first 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.

Most studies that look at long-term effects of treatment simply look at self-reported outcomes: level of pain and disability. This study took a different approach. By examining how much care patients sought after the initial study period, they could determine the effect each treatment method had on future health care consumption:

“Care seeking behavior by patients with low back pain is most commonly associated with increased pain and disability, meaning more care is sought when worse symptoms are experienced. The amount of health care utilized may therefore be used as a measure of patient health status, and thus may be compared between groups of patients to determine effectiveness of certain therapies.”

“Proctor et al.² determined that about 25% of patients with chronic, disabling, work-related musculoskeletal disorders pursue new health care services after completing a course of treatment, and among those who sought additional health care from a new provider, a subgroup of <15% accounted for a disproportionate share of lost worker productivity, more surgical procedures, and ongoing financial disputes. They further stated that in patients with chronic, disabling, work-related musculoskeletal disorders, post-treatment utilization of health care from a new provider is an important dimension of outcome…”

The authors started with 191 patients with low back pain. 107 patients received chiropractic care (flexion/distraction treatment, or FD) and 84 patients received active exercise therapy (EP) from physical therapists. All patients received treatment 2 to 4 times per week for four weeks. The study subjects were then followed for one year to assess outcomes. The authors found:

• 38% of the FD patients and 54% of the EP patients sought care for their back pain during the one-year follow-up.
• FD patients had an average of 2.2 visits to a health care provider after the treatment period, while EP patients had an average of 6 visits.

“We hypothesized that there would be no group difference in the average number of visits to any health care provider. The results demonstrated that actually there were significant group differences during the year after trial participation, with a higher number of visits to any health care provider and to a general practitioner in the EP group.”

The authors conclude:

“Based on one-year follow-up data imputed for complete analysis, participants who received physical therapy (exercise program) during a clinical trial attended a higher number of visits to any health care provider and to general practitioners during the year after care when compared to participants who received chiropractic care (flexion distraction) within the trial.”

1. Cambron JA, Gudavalli MR, McGregor M, et al. Amount of health care and self-care following a randomized clinical trial comparing flexion-distraction with exercise program for chronic low back pain. Chiropractic and Osteopathy 2006:14:19.
2. Proctor TJ, Mayer TG, Gatchel RJ, McGreary DD: Unremitting health care utilization outcomes of tertiary rehabilitation of patients with chronic musculoskeletal disorders. Journal of Bone and Joint Surgery 2004, 86A:62-69. 

“One factor explaining these enormous costs is the high rate of recurrence and chronic disability related to low-back disorders…It has been suggested that only 10% of LBP patients generate more than 80% of the total costs related to LBP.”

Because of the enormous costs of treating chronic back pain, prevention is an important goal. This current study set out to examine the role of chiropractic in treating chronic low back pain. The authors studied 30 patients who had back pain for at least six months. All patients were subjected to a one-month control period that consisted of no treatment. This was included so that the researchers could observe the natural course of the back pain symptoms.

After this baseline period, half of the patients (Group 1) received intensive chiropractic treatment consisting of 12 treatments in one month, then no treatments for nine months. The other half of the patients (Group 2) received the same intensive treatment, but also received maintenance chiropractic treatments every 3 weeks for nine months. At the end of the nine-month period, both groups were again examined.

After analyzing the results, the authors found the following:

• Pain levels were reduced in both groups of patients. The intensive month of chiropractic adjustments reduced pain, even without follow-up care.
• Disability levels, however, showed a different response. For the patients with no continuing treatment, the disability levels returned to their pretreatment levels on the Oswestry. The Group 2 patients – who received maintenance care – continued to see improvement in disability scores over the whole nine months.

 The following graph illustrates the differences between the two groups on disability levels:

The authors conclude:

“This study appears to confirm previous reports showing that LBP and disability scores are reduced after spinal manipulation. It also shows the positive effects of preventive chiropractic treatment in maintaining functional capacities and reducing the number and intensity of pain episodes after an acute phase of treatment. Maintenance chiropractic care involving spinal manipulation combined with other treatment modalities (exercises, pain management program) should be investigated. Such combined interventions may have a critical influence on pain, disability, and return to work.”

Descarreaux M, Blouin JS, Drolet M, Papadimitriou S, Teasdale N. Efficacy of preventive spinal manipulation for chronic low-back pain and related disabilities: a preliminary study. Journal of Manipulative and Physiological Therapeutics 2004;27:509-514.