Effectiveness of paracetamol, diclofenac, and placebo for acute low back pain: Results of PACE Study

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Effectiveness of paracetamol, diclofenac, and placebo for acute low back pain: Results of PACE Study

Low back pain (LBP) is a musculoskeletal pain in the lower back region which currently has become a universal burdensome condition across the world. About 80 percent of the people suffer from LBP at some point in their life. Some guidelines are advising the management approaches like advice to stay active, avoid bed rest and use of analgesics like paracetamol, etc. as first-line treatment for LBP.

A PACE (Pacing, graded Activity, and Cognitive behaviour therapy) trial was conducted to estimate the efficacy of paracetamol that showed no difference in clinical outcomes between paracetamol and placebo used in patients with acute LBP. Unpredictability persists relative to the benefit of paracetamol and diclofenac and further impact of pain medication compared with advice only in patients with acute LBP.

Another PACE Plus trial was conducted which was a four-arm, multi-center, placebo-blinded, superiority randomized controlled trial. In this, a double-dummy technique in general practice in primary care was used, with a follow-up of 12 weeks. This trial determined the effectiveness of paracetamol, diclofenac, and placebo for acute LBP for 4 weeks. Furthermore, this trial checked the additional effect of paracetamol, diclofenac, and placebo compared with advice only for acute LBP over a period of 4 weeks.

The study included patients 1) aged between 18 and 60 years and LBP (< 6 weeks’ duration) 2) primary complaint of pain between the 12th rib and buttock crease region, with or without radiating leg pain, 3) Suffering a new episode of LBP, preceded by a period of at least 1 month without LBP; 5) severe enough LBP (≥4 on 0–10 numerical rating scale (NRS)).

Patients were randomized into four groups: 1) Advice only (clinical guideline of the Dutch College of General Practitioners); 2) Advice and paracetamol; 3) Advice and diclofenac; 4) Advice and placebo.

The primary outcome measured the intensity of LBP for 4 weeks’ period, using numerical rating scale (0–10). Secondary outcomes were measured at 1 week, 2 weeks, 4 weeks and 12 weeks of follow-up and include compliance to treatment, disability, perceived recovery, costs, adverse reactions, satisfaction, sleep quality, co-interventions and adequacy of blinding.

Between-group differences for LBP, intensity would be evaluated using a repeated measurement analysis with linear effects models. An economic evaluation would be estimated through cost-effective analysis with LBP intensity and a cost-utility analysis with the quality of life. Explorative analyses would be done to evaluate the effect modification by predefined variables. The outcomes might influence the clinical guideline recommendations with regards to first analgesic treatment options in acute LBP in general practice.

Recruitment of patients according to inclusion criteria is currently ongoing. Any considerable protocol amendments would be conveyed to participants, cooperating general physicians and pharmacists, Medical Research and Ethics Committee (MREC), the Dutch Trial Registry, ZonMw and the journal publishing this protocol. Results of this trial would be published in a peer-reviewed journal. Trial results would be informed to participating patients and general physicians after its publication, and the final results are expected in 2020.


BMC Musculoskeletal Disorders

Link to the source


Original title of article:

Efficacy of paracetamol, diclofenac and advice for acute low back pain in general practice: design of a randomized controlled trial (PACE Plus)


Marie-Hélène Drouineau, Elise Guenegoa et al. 

Therapeutic, Paracetamol, Diclofenac, Low Back Pain (LBP), Spine, Analgesic, NSAIDs, Multi-center, Placebo-blinded, Randomized Controlled Trial, Efficacy, NRS
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