- Kenny Lin, MD, MPH
Although a referral to physical therapy is a standard part of my treatment plan for patients with subacute or chronic low back pain, there is little data on the effectiveness of physical therapy for acute back pain. A 2018 Family Physicians Inquiries Network (FPIN) Clinical Inquiry published in American Family Physician found that physical therapy begun within 24 hours of clinical presentation provides minimal improvements in pain, satisfaction, and mental health at one week that disappear by one month. Physical therapy started within 48 to 72 hours of presentation had no significant effects on pain or disability. A 2002 randomized trial found no differences in pain or activities of daily living in patients with acute low back pain with sciatica who were assigned to bed rest, physical therapy, or a control group. A 2008 study reported that physical therapy added to usual care from a general practitioner improved patients' global perceived effect but had no effects on pain or disability. Another FPIN Clinical Inquiry on treatments for sciatica concluded that nonsteroidal anti-inflammatory drugs, systemic steroids, topiramate, pregabalin, traction, and best rest were all ineffective and had potential adverse effects. The authors did not review physical therapy.
A single-blind randomized controlled trial published today in the Annals of Internal Medicine compared early referral to physical therapy to usual care in 220 adults aged 18 to 60 years with acute back pain with sciatica for less than 90 days. Participants were recruited from primary care practices in two health care systems (Intermountain Healthcare and University of Utah). All participants received an evidence-based patient education booklet about low back pain; patients assigned to the intervention group were scheduled for 6 to 8 exercise and manual therapy sessions over 4 weeks with one of the study physical therapists. The primary outcome was change in the Oswestry Disability Index (OSW) score from baseline after 6 months.
Compared to the usual care group, intervention group participants reported greater improvements in OSW scores at 6 months (5.4 points) and 1 year (4.8 points). They also had lower back pain intensity and were more likely to report treatment success after 1 year (45% vs. 28% for usual care). However, health care use and missed workdays were not significantly different between groups.
Although this study's results appear to support early referral to physical therapy for patients with acute back pain with sciatica, they come with some caveats. The minimal clinically important difference on the OSW for this condition is 6 to 8 points, greater than the mean point estimates of between-group differences seen in this study. Also, since participants were not blinded to their group assignment and the usual care group did not receive sessions with a comparable contact time as the physical therapy sessions, it's possible that the modest improvement had less to do with the therapy than the caring attention that patients received from the therapists. The cost-effectiveness of referring every patient with this condition to a physical therapist is also uncertain.
Nonetheless, given the limited options currently available for patients with acute back pain with sciatica, it seems reasonable for family physicians to offer a referral to a physical therapist rather than prescribing ineffective pharmacotherapy or obtaining unnecessary and potentially harmful imaging studies.