» Articles » PMID: 36877823

Standing on the Shoulders of Bias: Lack of Transparency and Reporting of Critical Rigor Characteristics in Pain Research

Abstract

Rigorous experimental design with transparent reporting in biomedical science reduces risk of bias and allows for scientists to judge the quality of the research. Basic factors of rigor such as blinding, randomization, power analysis, and inclusion of both sexes impact the reproducibility by reducing experimental bias. We designed a systematic study to analyze basic factors of rigor, inclusion of sex, and whether data were analyzed or disaggregated by sex over the past 10 years in the journal PAIN . Studies that included humans reported randomization in 81%, blinding in 48%, and the use of a power analysis calculation in 27% over the past 10 years. Studies that included mice reported randomization in 35%, blinding in 70%, and the use of a power analysis in 9%. Studies that included rats reported randomization in 38%, blinding in 63%, and the use of power analysis in 12%. This study also found that human studies consistently included both sexes over the past decade, but less than 20% of data were disaggregated or analyzed for sex differences. Although mouse and rat studies predominately used males only, there has been a slight increase in inclusion of both sexes over the past few years. Justification for single-sex studies was below 50% in both human and rodent data. In both human and animal studies, transparency in reporting of experimental design and inclusion of both sexes should be considered standard practice and will result in improved quality and reproducibility of published research.

Citing Articles

The influence of sex on activity in voluntary wheel running, forced treadmill running, and open field testing in mice.

Janowski A, Berardi G, Hayashi K, Plumb A, Lesnak J, Khataei T Physiol Rep. 2025; 13(4):e70246.

PMID: 39985141 PMC: 11845322. DOI: 10.14814/phy2.70246.


Pregabalin produces analgesia in males but not females in an animal model of chronic widespread muscle pain.

Plumb A, Hayashi K, Janowski A, Smith A, Rasmussen L, Sluka K Pain Rep. 2024; 9(6):e1207.

PMID: 39574484 PMC: 11581757. DOI: 10.1097/PR9.0000000000001207.


Brain-derived neurotrophic factor contributes to activity-induced muscle pain in male but not female mice.

Hayashi K, Lesnak J, Plumb A, Janowski A, Smith A, Hill J bioRxiv. 2023; .

PMID: 37961342 PMC: 10635076. DOI: 10.1101/2023.10.31.565022.


Neuroimmune Mechanisms Underlying Post-acute Sequelae of SARS-CoV-2 (PASC) Pain, Predictions from a Ligand-Receptor Interactome.

Lesnak J, Mazhar K, Price T Curr Rheumatol Rep. 2023; 25(9):169-181.

PMID: 37300737 PMC: 10256978. DOI: 10.1007/s11926-023-01107-8.


Influence of routine exercise on the peripheral immune system to prevent and alleviate pain.

Lesnak J, Berardi G, Sluka K Neurobiol Pain. 2023; 13:100126.

PMID: 37179769 PMC: 10173010. DOI: 10.1016/j.ynpai.2023.100126.

References
1.
Johnson J, Sharman Z, Vissandjee B, Stewart D . Does a change in health research funding policy related to the integration of sex and gender have an impact?. PLoS One. 2014; 9(6):e99900. PMC: 4070905. DOI: 10.1371/journal.pone.0099900. View

2.
Macleod M, van der Worp H, Sena E, Howells D, Dirnagl U, Donnan G . Evidence for the efficacy of NXY-059 in experimental focal cerebral ischaemia is confounded by study quality. Stroke. 2008; 39(10):2824-9. DOI: 10.1161/STROKEAHA.108.515957. View

3.
Mogil J . Sex differences in pain and pain inhibition: multiple explanations of a controversial phenomenon. Nat Rev Neurosci. 2012; 13(12):859-66. DOI: 10.1038/nrn3360. View

4.
Lesnak J, Inoue S, Lima L, Rasmussen L, Sluka K . Testosterone protects against the development of widespread muscle pain in mice. Pain. 2020; 161(12):2898-2908. PMC: 7669728. DOI: 10.1097/j.pain.0000000000001985. View

5.
Johnson J, Beaudet A . Sex and gender reporting in health research: why Canada should be a leader. Can J Public Health. 2013; 104(1):e80-1. PMC: 6973991. View