Meta-analysis comparing placebo responses in clinical trials of painful HIV-associated sensory neuropathy and diabetic polyneuropathy
File(s)PlaceboHIV_CleanResptoRev_v2.docx (355.19 KB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Background and aims The placebo response has been identified as one factor responsible for the lack of therapeutic trials with positive outcomes in neuropathic pain. Reviews have suggested that certain neuropathic pain conditions, including HIV-associated sensory neuropathy (HIV-SN), exhibit a greater placebo response than other neuropathic aetiologies. If true, such a finding could substantially affect clinical trial design and therapeutic developments for these conditions. This study aimed to identify any difference in placebo response between trials of systemic pharmacological intervention in HIV-SN and a comparable neuropathic condition, diabetic polyneuropathy (DPN) and to identify factors influencing the placebo response. Methods A systematic review search to identify randomised, double-blind studies of systemic pharmacological interventions for painful HIV-SN and DPN published between January 1966 and June 2019 was performed. A meta-analysis of the magnitude of placebo response and the proportion of placebo responders was conducted and compared between the two disease conditions. A meta-regression was used to assess for any study and participant characteristics that were associated with the placebo response. Only studies meeting a methodological quality threshold were included. Results Seventy-five trials were identified. There was no statistically significant difference in the proportion of placebo responders (HIV-SN = 0.35; versus DPN = 0.27, p = 0.129). The difference observed in the magnitude of the placebo response [pain reduction of 1.68 (1.47-1.88) DPN; 2.38 (1.87-2.98) in HIV-SN] was based on only 2 trials of HIV-SN and 35 of DPN. Potential factors influencing the placebo response such as psychological measures, were reported inconsistently. Conclusions We found no statistically significant difference in the placebo response rate between painful HIV-SN and DPN. Too few studies were available that reported the necessary information to clarify potential differences in the magnitude of placebo response or to elucidate parameters that could be contributing such differences. Implications The placebo response is one factor that may contribute to a lack of positive trials in neuropathic pain; some etiologies may display larger responses than others. This meta-analysis found no significant difference in placebo response between trials of HIV-associated sensory neuropathy and painful diabetic polyneuropathy, although limited data were available.
Date Issued
2020-07-01
Date Acceptance
2020-01-15
Citation
Scandinavian Journal of Pain, 2020, 20 (3), pp.439-449
ISSN
1877-8860
Publisher
Elsevier
Start Page
439
End Page
449
Journal / Book Title
Scandinavian Journal of Pain
Volume
20
Issue
3
Copyright Statement
© 2020 Scandinavian Association for the Study of Pain. Published by Walter de Gruyter GmbH, Berlin/Boston. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/32106088
PII: /j/sjpain.ahead-of-print/sjpain-2019-0152/sjpain-2019-0152.xml
Subjects
HIV
neuropathic pain
neuropathy, painful
painful diabetic neuropathy
placebo
Publication Status
Published
Coverage Spatial
Germany
Date Publish Online
2020-02-27