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

A Systematic Review of Clinical Practice Guidelines for Persons With Non-specific Low Back Pain With and Without Radiculopathy: Identification of Best Evidence for Rehabilitation to Develop the WHO's Package of Interventions for Rehabilitation

OBJECTIVE

To Identify evidence-based rehabilitation interventions for persons with non-specific low back pain (LBP) with and without radiculopathy and to develop recommendations from high-quality clinical practice guidelines (CPGs) to inform the World Health Organization's (WHO) Package of Interventions for Rehabilitation (PIR).

DATA SOURCE

We searched MEDLINE, EMBASE, CINAHL, PsycINFO, National Health Services Economic Evaluation Database, Health Technology Assessment Database, PEDro, the Trip Database, the Index to Chiropractic Literature and the gray literature.

STUDY SELECTION

Eligible guidelines were (1) published between 2009 and 2019 in English, French, Italian, or Swedish; (2) included adults or children with non-specific LBP with or without radiculopathy; and (3) assessed the benefits of rehabilitation interventions on functioning. Pairs of independent reviewers assessed the quality of the CPGs using AGREE II.

DATA SYNTHESIS

We identified 4 high-quality CPGs. Recommended interventions included (1) education about recovery expectations, self-management strategies, and maintenance of usual activities; (2) multimodal approaches incorporating education, exercise, and spinal manipulation; (3) nonsteroidal anti-inflammatory drugs combined with education in the acute stage; and (4) intensive interdisciplinary rehabilitation that includes exercise and cognitive/behavioral interventions for persistent pain. We did not identify high-quality CPGs for people younger than 16 years of age.

CONCLUSION

We developed evidence-based recommendations from high-quality CPGs to inform the WHO PIR for people with LBP with and without radiculopathy. These recommendations emphasize the potential benefits of education, exercise, manual therapy, and cognitive/behavioral interventions.

Diclofenac Administration after Physical Training Blunts Adaptations of Peripheral Systems and Leads to Losses in Exercise Performance: In Vivo and In Silico Analyses

Recovery in athletes is hampered by soreness and fatigue. Consequently, nonsteroidal anti-inflammatory drugs are used as an effective strategy to maintain high performance. However, impact of these drugs on adaptations induced by training remains unknown. This study assessed the effects of diclofenac administration (10 mg/kg/day) on rats subjected to an exhaustive test, after six weeks of swimming training. Over the course of 10 days, three repeated swimming bouts were performed, and diclofenac or saline were administered once a day. Trained animals exhibited higher muscle citrate synthase and lower plasma creatinine kinase activities as compared to sedentary animals, wherein diclofenac had no impact. Training increased time to exhaustion, however, diclofenac blunted this effect. It also impaired the increase in plasma and liver interleukin-6 levels. The trained group exhibited augmented catalase, glutathione peroxidase, and glutathione reductase activities, and a higher ratio of reduced-to-oxidized glutathione in the liver. However, diclofenac treatment blunted all these effects. Systems biology analysis revealed a close relationship between diclofenac and liver catalase. These results confirmed that regular exercise induces inflammation and oxidative stress, which are crucial for tissue adaptations. Altogether, diclofenac treatment might be helpful in preventing pain and inflammation, but its use severely affects performance and tissue adaptation.

Interpretation of trial-based economic evaluations of musculoskeletal physical therapy interventions

BACKGROUND

As resources for healthcare are scarce, decision-makers increasingly rely on economic evaluations when making reimbursement decisions about new health technologies, such as drugs, procedures, devices, and equipment. Economic evaluations compare the costs and effects of two or more interventions. Musculoskeletal disorders have a high prevalence and result in high levels of disability and high costs worldwide. Because physical therapy interventions are usually the first line of treatment for musculoskeletal disorders, economic evaluations of such interventions are becoming increasingly important for stakeholders in the field of physical therapy, including physical therapists, decision-makers, and reseachers. However, economic evaluations are relatively difficult to interpret for the majority of stakeholders.

OBJECTIVE

To support physical therapists, decision-makers, and researchers in the field of physical therapy interpreting trial-based economic evaluations and translating the results of such studies to clinical practice.

METHODS

The design, analysis, and interpretation of economic evaluations performed alongside randomized controlled trials are discussed. To further illustrate and explain these concepts, we use a case study assessing the cost-effectiveness of exercise therapy compared to standard advice in patients with musculoskeletal disorders.

CONCLUSIONS

Economic evaluations are increasingly being used in healthcare decision-making. Therefore, it is of utmost importance that their design, conduct, and analysis are state-of-the-art and that their interpretation is adequate. This masterclass will help physical therapists, decision-makers, and researchers in the field of physical therapy to critically appraise the quality and results of trial-based economic evaluations and to apply the results of such studies to their own clinical practice and setting.

The effect of oral magnesium supplementation on acute non-specific low back pain: Prospective randomized clinical trial

OBJECTIVE

We aimed to investigate the effect of oral magnesium supplementation for acute low back pain.

METHODS

This is a three-arm, prospective randomized open label clinical trial, which included two hundred and forty patients. We based our sample size calculation assumptions on a recently published clinical trial, thus we enrolled 80 patients for each group. NSAID alone group included (400 mg etodolac twice a day), NSAID + mg group included NSAID - magnesium combination treatment (400 mg etodolac twice a day with 365 mg oral magnesium supplementation) and NSAID + paracetamol group included NSAID - paracetamol combination treatment (400 mg etodolac twice a day with 500 mg paracetamol twice a day). Follow-up visits after initiation of relevant treatment were performed at 4th and 10th days and outcome measures included pain (Visual analogue scale - VAS), mobility of lumbar spine and functional outcome (RMDQ).

RESULTS

Thirty-one patients were considered lost to follow-up or excluded due to use of other medications and final analysis was performed with 209 participants in three groups (71 patients in NSAID alone group, 68 patients in NSAID + mg group and 70 patients in NSAID + paracetamol group). NSAID + mg showed a significantly higher improvement in RMDQ and VAS scores at acute stage (at 4th day visit) compared to two other study groups However, there was no significant difference between three groups in terms of mean improvement of RMDQ, VAS scores and lumbar mobility between initial visit and 10-day.

CONCLUSION

Results of this study suggest that addition of magnesium to acute low-back pain treatment does not significantly improve final clinical outcomes.

LEVEL OF EVIDENCE

Level I, prospective randomized controlled study.

Paracetamol for low back pain: the state of the research field

INTRODUCTION

Paracetamol is one of the most frequently used analgesics for people with low back pain, but despite its frequent use there is still debate regarding its efficacy and safety for this indication.

AREAS COVERED

We describe the origin of paracetamol and its proposed mechanisms of action. We focus in on low back pain and describe the evidence it has on the efficacy of paracetamol (taken by patients orally) and current insights on its side-effects. When searching for relevant publications we focused mainly on recent Cochrane reviews and published RCTs. We found that there is increasing evidence that shows paracetamol is not more effective than placebo in patients with acute low back pain. Concerning patients with subacute and chronic back pain, the evidence for or against the efficacy of paracetamol vs placebo is lacking and would need more research.

EXPERT OPINION

We argue that we still need better evidence on the efficacy of paracetamol for acute and chronic back pain. Until that evidence becomes available paracetamol should still be considered as an option for patients with back pain. However, we suggest that a strategy focusing on non-pharmacological management as the first treatment option in low back pain may be equally effective with less side effects.

Non-steroidal anti-inflammatory drugs for acute low back pain

BACKGROUND

Acute low back pain (LBP) is a common health problem. Non-steroidal anti-inflammatory drugs (NSAIDs) are often used in the treatment of LBP, particularly in people with acute LBP. In 2008, a Cochrane Review was published about the efficacy of NSAIDs for LBP (acute, chronic, and sciatica), identifying a small but significant effect in favour of NSAIDs compared to placebo for short-term pain reduction and global improvement in participants with acute LBP. This is an update of the previous review, focusing on acute LBP.

OBJECTIVES

To assess the effects of NSAIDs compared to placebo and other comparison treatments for acute LBP.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed, and two trials registers for randomised controlled trials (RCT) to 7 January 2020. We also screened the reference lists from relevant reviews and included studies.

SELECTION CRITERIA

We included RCTs that assessed the use of one or more types of NSAIDs compared to placebo (the main comparison) or alternative treatments for acute LBP in adults (≥ 18 years); conducted in both primary and secondary care settings. We assessed the effects of treatment on pain reduction, disability, global improvement, adverse events, and return to work.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials to be included in this review, evaluated the risk of bias, and extracted the data. If appropriate, we performed a meta-analysis, using a random-effects model throughout, due to expected variability between studies. We assessed the quality of the evidence using the GRADE approach. We used standard methodological procedures recommended by Cochrane.

MAIN RESULTS

We included 32 trials, with a total of 5356 participants (age range 16 to 78 years). Follow-up ranged from one day to six months. Studies were conducted across the globe, the majority taking place in Europe and North-America. Africa and the Eastern Mediterranean region were not represented. We considered seven studies at low risk of bias. Performance and attrition were the most common biases. There was often a lack of information on randomisation procedures and allocation concealment (selection bias); studies were prone to selective reporting bias, since most studies did not register their trials. Almost half of the studies were industry-funded. There is moderate quality evidence that NSAIDs are slightly more effective in short-term (≤ 3 weeks) reduction of pain intensity (visual analogue scale (VAS), 0 to 100) than placebo (mean difference (MD) -7.29 (95% confidence interval (CI) -10.98 to -3.61; 4 RCTs, N = 815). There is high quality evidence that NSAIDs are slightly more effective for short-term improvement in disability (Roland Morris Disability Questionnaire (RMDQ), 0 to 24) than placebo (MD -2.02, 95% CI -2.89 to -1.15; 2 RCTs, N = 471). The magnitude of these effects is small and probably not clinically relevant. There is low quality evidence that NSAIDs are slightly more effective for short-term global improvement than placebo (risk ratio (RR) 1.40, 95% CI 1.12 to 1.75; 5 RCTs, N = 1201), but there was substantial heterogeneity (I² 52%) between studies. There is very low quality evidence of no clear difference in the proportion of participants experiencing adverse events when using NSAIDs compared to placebo (RR 0.86, 95% CI 0.63 to 1.18; 6 RCTs, N = 1394). There is very low quality evidence of no clear difference between the proportion of participants who could return to work after seven days between those who used NSAIDs and those who used placebo (RR 1.48, 95% CI 0.98 to 2.23; 1 RCT, N = 266). There is low quality evidence of no clear difference in short-term reduction of pain intensity between those who took selective COX-2 inhibitor NSAIDs compared to non-selective NSAIDs (mean change from baseline -2.60, 95% CI -9.23 to 4.03; 2 RCTs, N = 437). There is moderate quality evidence of conflicting results for short-term disability improvement between groups (2 RCTs, N = 437). Low quality evidence from one trial (N = 333) reported no clear difference between groups in the proportion of participants experiencing global improvement. There is very low quality evidence of no clear difference in the proportion of participants experiencing adverse events between those who took COX-2 inhibitors and non-selective NSAIDs (RR 0.97, 95% CI 0.63 to 1.50; 2 RCTs, N = 444). No data were reported for return to work.

AUTHORS' CONCLUSIONS

This updated Cochrane Review included 32 trials to evaluate the efficacy of NSAIDs in people with acute LBP. The quality of the evidence ranged from high to very low, thus further research is (very) likely to have an important impact on our confidence in the estimates of effect, and may change the estimates. NSAIDs seemed slightly more effective than placebo for short-term pain reduction (moderate certainty), disability (high certainty), and global improvement (low certainty), but the magnitude of the effects is small and probably not clinically relevant. There was no clear difference in short-term pain reduction (low certainty) when comparing selective COX-2 inhibitors to non-selective NSAIDs. We found very low evidence of no clear difference in the proportion of participants experiencing adverse events in both the comparison of NSAIDs versus placebo and selective COX-2 inhibitors versus non-selective NSAIDs. We were unable to draw conclusions about adverse events and the safety of NSAIDs for longer-term use, since we only included RCTs with a primary focus on short-term use of NSAIDs and a short follow-up. These are not optimal for answering questions about longer-term or rare adverse events.

Inferential reproduction analysis demonstrated that "paracetamol for acute low back pain" trial conclusions were reproducible

OBJECTIVES

The aim of this study was to reanalyze and reinterpret data obtained in Paracetamol in Acute Low Back Pain (PACE), the first large randomized controlled trial evaluating the efficacy of paracetamol in acute low back pain, to assess the inferential reproducibility of the original conclusions.

STUDY DESIGN AND SETTING

Mixed effects models were used to reanalyze pain intensity (primary outcome; 11-point Numeric Rating Scale) and physical functioning, health-related quality of life, sleep quality, and time until recovery (as secondary outcomes), according to the intention-to-treat principle. The original authors of the PACE study were not involved in the development of the methods for this reanalysis.

RESULTS

The reproduction analyses indicated no effect of treatment on pain intensity and confidence intervals excluded clinically worthwhile effects (adjusted main effect for regular paracetamol vs. placebo 0.00 [-0.02, 0.01; P = 0.85]; adjusted main effect for paracetamol as-needed vs. placebo 0.00 [-0.02, 0.01; P = 0.92]). Similar results were obtained for all secondary outcomes.

CONCLUSION

This study indicates that the conclusions of the PACE trial are inferentially reproducible, even when using a different analytical approach. This reinforces the notion that the management of acute low back pain should focus on providing patients advice and reassurance without the addition of paracetamol.

Diclofenac attenuates inflammation through TLR4 pathway and improves exercise performance after exhaustive swimming

BACKGROUND

The use of NSAIDs has become a common practice to counteract the pro-inflammatory acute effects of exercise, in order to improve sports performance. The liver, due to its central role in energy metabolism, may be involved primarily in the process of ROS generation and consequently inflammation after exhaustive exercise.

OBJECTIVE

To analyze the influence of diclofenac on the liver TLR4 pathway and time to exhaustion in rats submitted to repeated exhaustive swimming.

METHODS

An exhaustive test was performed in order to mimic athletes' routine, and inflammatory status and oxidative stress markers were evaluated in the liver. Animals were divided into sedentary and exhaustion groups, with this last performing three exhaustive swimming bouts. At the same time, diclofenac or saline was pre-administered once a day for nine days.

RESULTS

Data showed significantly increased COX-2, TLR4, and MyD88 protein content in the liver after exhaustive swimming bouts. The levels of pro-inflammatory cytokines also increased after exhaustive exercise, while these effects were attenuated in the group treated with diclofenac plus exhaustive swimming bouts. The anti-inflammatory modulation provoked by diclofenac treatment was associated with an increased time to exhaustion in the exercise bouts. The exhaustive exercise increased TBARS formation, but diclofenac treatment blunted this elevation, while GSH/GSSG ratios in both exhaustion-saline and exhaustion-diclofenac-treated groups were lower than in the sedentary-saline group.

CONCLUSIONS

Our findings suggest that diclofenac may improve exercise performance and represent an effective tool to ameliorate the pro-inflammatory status in liver when associated with exhaustive exercise, and the liver may be a possible therapeutic target.

Discontinuation of the PACE Plus trial: problems in patient recruitment in general practice

BACKGROUND

The PACE Plus trial was a multi-center, double-blinded, superiority randomized controlled trial (RCT) conducted in patients from Dutch general practice to investigate the efficacy of paracetamol and NSAIDs in acute non-specific low back pain (LBP). Because insufficient numbers of patients could be recruited (only four out of the required 800 patients could be recruited over a period of 6 months), the trial was prematurely terminated in February 2017, 6 months after the start of recruitment. This article aims to transparently communicate the discontinuation of PACE Plus and to make recommendations for future studies.

METHODS

General Practitioners (GPs) from 36 participating practices received a one-question survey in which they were asked to give the three most important factors that in their opinion contributed to failure of patient recruitment.

RESULTS

GPs of 33 out of 36 (92%) participating practices sent a response. A total of 81 factors were reported. These have been categorized into patient factors (26 out of 81 comments, 32%), GP factors (39 out of 81 comments, 48%) and research factors (16 out of 81 comments, 20%).

DISCUSSION

Patient recruitment in the PACE Plus trial may have failed due to inefficient medication distribution, recruitment of incident rather than prevalent cases, a design that was too complicated, adequate self-management of LBP, patient expectations different from the trial's scope and lack of time of participating GPs. Substantial differences in design may explain why the preceding PACE trial did manage to successfully complete patient recruitment.

CONCLUSION

Although the PACE Plus trial was terminated as a result of insufficient patient inclusion, the research questions addressed in this trial remain relevant but unanswered. We hope that lessons learned from the discontinuation of PACE Plus and corresponding recommendations may be helpful in the design of upcoming research projects in LBP in general practice.

TRIAL REGISTRATION

Dutch Trial Registration NTR6089, registered September 14th 2016.