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5MinuteConsult Journal Club

Early Physical Therapy for Acute Low Back Pain and Sciatica


Cheng CW, Wu TX, Shang HC, et al; CONSORT-CHM Formulas 2017 Group. CONSORT Extension for Chinese Herbal Medicine Formulas 2017: Recommendations, Explanation, and Elaboration (Traditional Chinese Version).Ann Intern Med 2017 Jul 18;167(2):W7-W20. doi: 10.7326/IsTranslatedFrom_M17-2977_1. Epub 2017 Jun 27. PMID: 28654988.

Study Summary

Randomized controlled trial of 220 adults (18-60) with acute low back pain with sciatica were treated with usual care (one visit with medications and imaging as needed) vs. usual care plus referral for 4 weeks of physical therapy that included exercise and manual therapy. The PT group had improved outcomes at 4 weeks, 6 months and 1 year after randomization on the Oswestry Disability Index and other secondary measures. At one year, 45% of the PT group reported treatment success compared to 28% in the usual care group (NNT = 6). There were no adverse events in the treatment group. 


For adult patients with acute low back pain and sciatica, 4 weeks of physical therapy using exercises and manual therapy resulted in improved short- and long-term outcomes with a greater chance of treatment success at one year. 

Stats Refresher

The number needed to treat (NNT) is a measure to give providers and patients an idea of how useful an intervention is at treating a problem. The lower the NNT, the more likely the patient will receive a benefit from that intervention. 

It is calculated by taking the inverse of the absolute risk reduction. In this case, that would be 100/(45-28) = 100/17 ~ 6. To explain this to a patient, you would say “I would need to treat 6 patients like you with physical therapy for one additional patient to have a benefit.” 

Another measure, the number needed to harm (NNH), is calculated in the same manner (100/absolute risk increase of an adverse outcome) with the higher the NNH, the better, implying a lower risk of an adverse event. 

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Contributed by Frank J. Domino, MD,