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High Outcome-Reporting Bias in Randomized-Controlled Trials of Acupuncture for Cancer Chemotherapy-Induced Nausea and Vomiting: A Systematic Review and Meta-Epidemiological Study
by
, , and
Rachele Penati
1,2,†
,
Riccardo Vecchio
3,†
,
Roberto Gatto
2,
Anna Odone
3 and
Silvia Deandrea
2,3,* 1
Villa Beretta Rehabilitation Center, Valduce Hospital, 23845 Costa Masnaga, Italy
2
Centro Studi So Wen ETS, 20146 Milano, Italy
3
Department of Public Health, Experimental and Forensic Medicine, University of Pavia, 27100 Pavia, Italy
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Curr. Oncol. 2025, 32(8), 462; https://doi.org/10.3390/curroncol32080462
Submission received: 11 June 2025
/
Revised: 8 August 2025
/
Accepted: 13 August 2025
/
Published: 15 August 2025
Simple Summary
Reporting all the results of scientific studies is important to make sure treatments are tested fairly and transparently. We looked at clinical studies that tested acupuncture to reduce nausea and vomiting caused by cancer treatments. We found that many of these studies did not describe their results completely or clearly, and some had not been registered in public databases before starting. Our study shows that more attention should be given to clear, complete, and early reporting of outcomes in clinical research, especially when treatments are based on patient-reported symptoms. Following these good practices can improve future studies and help doctors and patients make better-informed decisions.
Abstract
Selective outcome-reporting bias refers to the selective reporting of a subset of study findings. This methodological limitation may occur in cancer-related acupuncture studies, where valid empirical studies on psychometric performance are still lacking. We assessed the risk of selective outcome reporting bias in studies published in English that were included in a systematic review on acupuncture for preventing cancer chemotherapy-induced nausea and vomiting. For each study, we searched for registry availability and, if present, assessed its validity. We described each study outcome (nausea, vomiting, or both) according to the following seven items: type of outcome, domain, specific measurement, specific metric, type of data, methods of aggregation, and timepoint unit and time. Eleven studies published between 1987 and 2019 in English were evaluated. Only four (36%) had a registry, of which only two were prospective and therefore considered valid. Discrepancies were found in the specific measurement of the outcome in two studies and in the specific metric. In many other cases, discrepancies were not evaluable due to missing information. No study reported complete outcomes as planned in the published protocol. Communication about the importance of prospective trial registration, including outcome details, should be enforced to reduce the risk of selective outcome reporting bias in oncology acupuncture studies.
Keywords:
bias; complementary therapies; nausea; vomiting; chemotherapy; acupuncture therapy
