The Chiropractic Hospital-based Interventions Research Outcomes (CHIRO) study: a randomized controlled trial on the effectiveness of clinical practice guidelines in the medical and chiropractic management of patients with acute mechanical low back pain

Background context: Evidence-based clinical practice guidelines (CPGs) for the management of patients with acute mechanical low back pain (AM-LBP) have been defined on an international scale. Multicenter clinical trials have demonstrated that most AM-LBP patients do not receive CPG-based treatments. To date, the value of implementing full and exclusively CPG-based treatment remains unclear.

Purpose: To determine if full CPGs-based study care (SC) results in greater improvement in functional outcomes than family physician-directed usual care (UC) in the treatment of AM-LBP.

Study design/setting: A two-arm, parallel design, prospective, randomized controlled clinical trial using blinded outcome assessment. Treatment was administered in a hospital-based spine program outpatient clinic.

Patient sample: Inclusion criteria included patients aged 19 to 59 years with Quebec Task Force Categories 1 and 2 AM-LBP of 2 to 4 weeks' duration. Exclusion criteria included "red flag" conditions and comorbidities contraindicating chiropractic spinal manipulative therapy (CSMT).

Primary outcome: improvement from baseline in Roland-Morris Disability Questionnaire (RDQ) scores at 16 weeks.

Secondary outcomes: improvements in RDQ scores at 8 and 24 weeks; and in Short Form-36 (SF-36) bodily pain (BP) and physical functioning (PF) scale scores at 8, 16, and 24 weeks.

Methods: Patients were assessed by a spine physician, then randomized to SC (reassurance and avoidance of passive treatments, acetaminophen, 4 weeks of lumbar CSMT, and return to work within 8 weeks), or family physician-directed UC, the components of which were recorded.

Results: Ninety-two patients were recruited, with 36 SC and 35 UC patients completing all follow-up visits. Baseline prognostic variables were evenly distributed between groups. The primary outcome, the unadjusted mean improvement in RDQ scores, was significantly greater in the SC group than in the UC group (p=.003). Regarding unadjusted mean changes in secondary outcomes, improvements in RDQ scores were also greater in the SC group at other time points, particularly at 24 weeks (p=.004). Similarly, improvements in SF-36 PF scores favored the SC group at all time points; however, these differences were not statistically significant. Improvements in SF-36 BP scores were similar between groups. In repeated-measures analyses, global adjusted mean improvement was significantly greater in the SC group in terms of RDQ (p=.0002), nearly significantly greater in terms of SF-36 PF (p=.08), but similar between groups in terms of SF-36 BP (p=.27).

Conclusions: This is the first reported randomized controlled trial comparing full CPG-based treatment, including spinal manipulative therapy administered by chiropractors, to family physician-directed UC in the treatment of patients with AM-LBP. Compared to family physician-directed UC, full CPG-based treatment including CSMT is associated with significantly greater improvement in condition-specific functioning.