Dataset Information

Neuropathic pain clinical trials: factors associated with decreases in estimated drug efficacy.

ABSTRACT: Multiple recent pharmacological clinical trials in neuropathic pain have failed to show beneficial effect of drugs with previously demonstrated efficacy, and estimates of drug efficacy seems to have decreased with accumulation of newer trials. However, this has not been systematically assessed. Here, we analyze time-dependent changes in estimated treatment effect size in pharmacological trials together with factors that may contribute to decreases in estimated effect size. This study is a secondary analysis of data from a previous published NeuPSIG systematic review and meta-analysis, updated to include studies published up till March 2017. We included double-blind, randomized, placebo-controlled trials examining the effect of drugs for which we had made strong or weak recommendations for use in neuropathic pain in the previously published review. As the primary outcome, we used an aggregated number needed to treat for 50% pain reduction (alternatively 30% pain reduction or moderate pain relief). Analyses involved 128 trials. Number needed to treat values increased from around 2 to 4 in trials published between 1982 and 1999 to much higher (less effective) values in studies published from 2010 onwards. Several factors that changed over time, such as larger study size, longer study duration, and more studies reporting 50% or 30% pain reduction, correlated with the decrease in estimated drug effect sizes. This suggests that issues related to the design, outcomes, and reporting have contributed to changes in the estimation of treatment effects. These factors are important to consider in design and interpretation of individual study data and in systematic reviews and meta-analyses.

SUBMITTER: Finnerup NB

PROVIDER: S-EPMC6193835 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Neuropathic pain clinical trials: factors associated with decreases in estimated drug efficacy.

Finnerup Nanna B NB Haroutounian Simon S Baron Ralf R Dworkin Robert H RH Gilron Ian I Haanpaa Maija M Jensen Troels S TS Kamerman Peter R PR McNicol Ewan E Moore Andrew A Raja Srinivasa N SN Andersen Niels T NT Sena Emily S ES Smith Blair H BH Rice Andrew S C ASC Attal Nadine N

Pain 20181101 11

Multiple recent pharmacological clinical trials in neuropathic pain have failed to show beneficial effect of drugs with previously demonstrated efficacy, and estimates of drug efficacy seems to have decreased with accumulation of newer trials. However, this has not been systematically assessed. Here, we analyze time-dependent changes in estimated treatment effect size in pharmacological trials together with factors that may contribute to decreases in estimated effect size. This study is a second ...[more]

PMID: 30015707

Similar Datasets

Project description:BackgroundCharacterizing relationships between pain relief and function can inform patient management decisions. This analysis explored graphically the relationship between pain relief and functional improvement in patients with neuropathic pain associated with spinal cord injury in two clinical trials of pregabalin.MethodsThis was a post hoc analysis of two randomized, double-blind, clinical trials in patients who were treated with pregabalin (n=181) or placebo (n=172) for neuropathic pain associated with spinal cord injury. The bivariate relationship between percent pain relief and absolute change in the functional outcomes with placebo and pregabalin was evaluated graphically using scatter plots, and loess curves illustrated the extent of the relationship between pain and function. Linear trend analysis evaluated the statistical significance of these relationships using Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT)-based thresholds of pain reduction (<15%, 15% <30%, 30% to <50%, and ≥50%). Outcome measures included modified Brief Pain Inventory pain interference with function in one of the studies and the Medical Outcomes Study Sleep Scale (an 11-point Numeric Rating Scale) and the Hospital Anxiety and Depression Scale (HADS) for the pooled studies.ResultsData ellipses showed a shift with pregabalin relative to placebo toward greater improvement with increasing pain relief for all outcome measures except HADS. Loess curves suggested a relationship between increased pain relief and improved function except for HADS, with the clearest relationship observed for sleep. Linear trend analysis showed significant relationships between pain and Medical Outcomes Study Sleep Scale (P<0.0001) and between pain and function on the modified Brief Pain Inventory Interference Index and most individual items (P<0.05).ConclusionGreater functional improvements were generally achieved at higher levels of clinically significant pain reduction. Pregabalin resulted in shifts from placebo toward greater functional improvement with greater pain relief.

Project description:Background and objectiveLow back pain (LBP) is one of the most common chronic pain conditions. This paper reviews the available literature on the role of neuropathic mechanisms in chronic LBP and discusses implications for its clinical management, with a particular focus on pharmacological treatments.Databases and data treatmentLiterature searches were performed in PubMed, key pain congresses and ProQuest Dialog to identify published evidence on neuropathic back pain and its management. All titles were assessed for relevant literature.ResultsChronic LBP comprises both nociceptive and neuropathic components, however, the neuropathic component appears under-recognized and undertreated. Neuropathic pain (NP) is challenging to manage. Many patients with chronic LBP have pain that is refractory to existing treatments. Typically, less than half of patients experience clinically meaningful analgesia with oral pharmacotherapies; these are also associated with risks of adverse effects. Paracetamol and NSAIDs, although widely used for LBP, are unlikely to ameliorate the neuropathic component and data on the use of NP medications such as antidepressants and gabapentin/pregabalin are limited. While there is an unmet need for improved treatment options, recent data have shown tapentadol to have efficacy in the neuropathic component of LBP, and studies suggest that the capsaicin 8% patch and lidocaine 5% medicated plaster, topical analgesics available for the treatment of peripheral NP, may be a valuable additional approach for the management of neuropathic LBP.ConclusionsChronic LBP often has an under-recognized neuropathic component, which can be challenging to manage, and requires improved understanding and better diagnosis and treatment. WHAT DOES THIS REVIEW ADD?: Increased recognition and improved understanding of the neuropathic component of low back pain raises the potential for the development of mechanism-based therapies. Open and retrospective studies suggest that agents like tapentadol and topical analgesics - such as the capsaicin 8% patch and the lidocaine 5% medicated plaster - may be effective options for the treatment of neuropathic low back pain in defined patient groups.

Dataset Information

Neuropathic pain clinical trials: factors associated with decreases in estimated drug efficacy.

Publications

Neuropathic pain clinical trials: factors associated with decreases in estimated drug efficacy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets