Spinal manipulation and home exercise with advice for subacute and chronic back-related leg pain: a trial with adaptive allocation.
Context Few studies evaluate the comparative effectiveness of conservative treatments for back-related leg pain. Contribution This randomized trial, involving 192 adults with subacute or chronic back-related leg pain, compared 12 weeks of home exercise and advice with spinal manipulative therapy plus home exercise and advice. Spinal manipulative therapy with home exercise and advice improved self-reported pain and function outcomes more than exercise and advice alone at 12 weeks, but differences between groups were not present at 52 weeks except for some secondary outcomes. Caution The intervention was not blinded. Implication Spinal manipulative therapy combined with home exercise and advice can improve short-term outcomes in patients with back-related leg pain. The Editors Back-related leg pain (BRLP) is an important symptom commonly associated with pervasive low back pain (LBP) conditions and, despite its socioeconomic effect, has been generally understudied. With poorer prognosis and quality of life, persons with BRLP have greater pain severity and incur more work loss, medication use, surgery, and health-related costs than those with uncomplicated LBP (16). Most patients with BRLP are treated with prescription medications and injections, although little to no evidence supports their use (7, 8). Surgical approaches are also commonly applied, although there is only some evidence for short-term effectiveness compared with less invasive treatments (9). Concerns are mounting about the overuse, costs, and safety of these conventional medical treatments (1018), warranting identification of more conservative treatment options. Spinal manipulative therapy (SMT), exercise, and education promoting self-management are increasingly recommended as low-risk strategies for BRLP (19). Although limited, evidence shows that these conservative approaches can be effective (2026). A recent systematic review by our group showed that SMT is superior to sham SMT for acute BRLP in the short and long term; however, the evidence for subacute and chronic BRLP is inconclusive, and high-quality research is needed to inform clinical and health policy decisions (20). The underlying mechanisms of SMT seem to be multifactorial, including improvement in spinal stiffness, muscle recruitment, and synaptic efficacy of central neurons (27, 28). The purpose of this study was to test the hypothesis that the addition of SMT to home exercise and advice (HEA) would be more effective than HEA alone for patients with subacute and chronic BRLP. Methods Design Overview This pragmatic trial used a parallel design with allocation by minimization and has been described previously (29). Patients were recruited between 2007 and 2010, and follow-up was completed in 2011. Institutional review boards approved the study protocol, and all patients provided written consent. The primary outcomes and most secondary outcomes were self-reported; objective measures were obtained by blinded examiners. There were no important changes to methods after trial commencement. Settings and Patients The trial was conducted at institution-affiliated research clinics at Northwestern Health Sciences University (Minneapolis, Minnesota) and Palmer College of Chiropractic (Davenport, Iowa). Patients were recruited through newspaper advertisements, direct mail, and community posters. Interested patients were initially screened by telephone interviews, followed by 2 in-person baseline evaluation visits. Inclusion criteria were age 21 years or older; BRLP based on Quebec Task Force on Spinal Disorders classifications 2, 3, 4, or 6 (radiating pain into the proximal or distal part of the lower extremity, with or without neurologic signs) (30); BRLP severity of 3 or greater (scale of 0 to 10); a current episode of 4 weeks or more; and a stable prescription medication plan in the previous month. Exclusion criteria were Quebec Task Force on Spinal Disorders classifications of 1, 5, 7, 8, 9, 10, and 11 (pain without radiation into the lower extremities, progressive neurologic deficits, the cauda equina syndrome, spinal fracture, spinal stenosis, surgical lumbar spine fusion, several incidents of lumbar spine surgery, chronic pain syndrome, visceral diseases, compression fractures or metastases, blood clotting disorders, severe osteoporosis, and inflammatory or destructive tissue changes of the spine). Patients could not be receiving ongoing treatment of leg pain or LBP; be pregnant or nursing; have current or pending litigation for worker's compensation, disability, or personal injury; be unable to read or comprehend English; or have evidence of substance abuse. Allocation A Web-based program assigned patients to treatment after the second baseline visit using a minimization algorithm based on the Taves method (31), balancing on 7 baseline characteristics previously shown to influence outcomes (3234). Baseline characteristics included age, BRLP duration, neurologic signs, distress, positive straight leg raise, time spent driving a vehicle, and pain aggravation with coughing or sneezing. Patients were assigned in a 1:1 ratio, stratified by site. The allocation algorithm was prepared by the study statistician before enrollment, and its administration was concealed from study personnel. Interventions The intervention protocols were developed and tested in previous pilot studies (32, 33). Both interventions were intended to be pragmatic in nature (for example, modified to patient presentation and needs) and were informed by commonly recommended clinical practices, patient preferences, and promising research evidence (19, 3538). Eleven chiropractors with a minimum of 5 years of practice experience delivered SMT in the SMT plus HEA group. Thirteen providers (7 chiropractors, 5 exercise therapists, and 1 personal trainer) delivered the HEA intervention. When possible, patients worked with the same providers during the 12-week course of care; however, to accommodate patient and provider schedules during the intervention period, providers were trained to comanage patients. Treatment fidelity was facilitated through standardized training, manuals of operation, and clinical documentation forms that were monitored weekly by research staff. SMT Plus HEA Group As many as 20 SMT visits were allowed, each lasting 10 to 20 minutes, including a brief history and examination. Patients assigned to SMT plus HEA also attended 4 HEA visits, as described in the HEA Group section. For SMT visits, the primary focus of treatment was on manual techniques (including high-velocity, low amplitude thrust procedures or low-velocity, variable amplitude mobilization maneuvers to the lumbar vertebral or sacroiliac joints). The specific spinal level treated and the number and frequency of SMT visits were determined by the clinician on the basis of patient-reported symptoms, palpation, and pain provocation tests (39). Adjunct therapies to facilitate SMT were used as needed and included light soft-tissue techniques (that is, active and passive muscle stretching and ischemic compression of tender points) and hot or cold packs. To facilitate adherence to HEA, chiropractors asked about patients adherence, reaffirmed main HEA messages, and answered questions as needed. HEA Group Home exercise and advice were delivered in four 1-hour, one-on-one visits during the 12-week intervention. The main program goals were to provide patients with the tools to manage existing pain, prevent pain recurrences, and facilitate engagement in daily activities. Instruction and practice were provided for positioning and stabilization exercises to enhance mobility and increase trunk endurance. These were individualized to patients lifestyles, clinical characteristics (including positional sensitivities), and fitness levels. Positioning exercises included extension and flexion motion cycles (patients were encouraged to perform 25 repetitions 3 times per day in the lying, standing, or seated position) (33, 40). Stabilization exercises included pelvic tilt, quadruped, bridging, abdominal curl-ups, and side bridging with positional variations appropriate to patients tolerance and abilities (41). Patients were instructed to do 8 to 12 repetitions of each stabilization exercise every other day. Patients were also instructed in methods for developing spine posture awareness related to their activities of daily living, such as lifting, pushing and pulling, sitting, and getting out of bed (42). Information about simple pain-management techniques, including cold, heat, and movement, was also provided. Printed materials were distributed to take home and review. They included instructions of exercises with photos and a modification of the Back in Action book (43), emphasizing movement and restoration of normal function and fitness (35, 44). To facilitate adherence to HEA, providers called or e-mailed patients 3 times (at 1, 4, and 9 weeks) to reaffirm main messages and answer exercise-related questions. Outcomes and Measurements Patients demographic and clinical characteristics were collected at their first baseline visit through self-report questionnaires, histories, and physical examinations. Self-reported outcomes were collected at the baseline visit and at 3, 12, 26, and 52 weeks via questionnaires independent of study personnel influence. Patients were queried in each questionnaire about attempts to influence their responses. The primary outcome measure was patient-rated typical level of leg pain during the past week using an 11-point numerical rating scale, a reliable, valid, and important patient-centered outcome (36, 4547). The primary end points were 12 weeks, which was the end of the intervention phase, and the 52-week follow-up. A complete description of all secondary outcome measures is provided elsewhere (29). The measures reported in this article include LBP, disability measured with the modified RolandMorris Disability Questionnaire (4850), physical and