ArticlePain2020
Are there really only 2 kinds of people in the world? Evaluating the distribution of change from baseline in pain clinical trials.
Article in Pain, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
2 citing papers in PubMed, 1 synthesis or guideline pooled it, 6 citations in OpenAlex.
- Topical clonidine for neuropathic pain in adults.The Cochrane database of systematic reviews · 2022Pooled it
- Cutoff criteria for the placebo response: a cluster and machine learning analysis of placebo analgesia.Scientific reports · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 1 country.
Funding
Abstract
It is often assumed that there are 2 types of pain patients: those who respond well to efficacious pain therapies and those who do not respond at all, with few people in the middle. This assumption is based on research that claims that changes in pain intensity have a bimodal distribution. The claim of bimodality has led to calls for a change in how pain clinical trials are designed and analyzed, eg, performing "responder" analyses instead of comparing group mean values to evaluate the treatment effect. We analyzed data from 4 clinical trials, 2 each of duloxetine and pregabalin, for chronic musculoskeletal and neuropathic pain conditions to critically examine the claim of bimodality of the distribution of change in pain intensity. We found that the improper construction of histograms, using unequal bin widths, was the principal flaw leading to the bimodality claim, along with the use of the oft-criticized baseline observation carried forward method for imputing missing data also serving as a contributing factor. Properly constructed histograms of absolute change in pain intensity using equal bin widths, combined with more principled methods for handling missing data, resulted in distributions that had a more unimodal appearance. Although our findings neither support nor refute the hypothesis that distinct populations of "responders" and "nonresponders" to pain interventions exist, the analyses presented in earlier work do not provide support for this hypothesis, nor for the recommendation that pain clinical trials prioritize "responder" analyses, a less efficient analysis strategy.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.