OBJECTIVES

To systematically investigate trustworthiness (methodological rigor, transparency, good governance, research integrity, and absence of misconduct) in randomized controlled trials (RCTs) of osteopathic manual therapy.

METHODS

This prospectively registered review (PROSPERO-ID: CRD42023457697) searched MEDLINE, EMBASE, CINAHL, AMED, PEDro, ostmed.dr, and Chiroindex for RCTs evaluating osteopathic treatments (January 2021-June 2024). Risk of bias (RoB) was assessed using Cochrane tool 2, while trustworthiness was assessed with the Cochrane Pregnancy and Childbirth Screening Tool and the REAPPRAISED checklist. Journal trustworthiness, misleading representations in abstracts ("spin"), and results plausibility (via meta-analysis) were also assessed. Findings were synthesized descriptively.

RESULTS

Sixty-one RCTs were included (median sample size 45, interquartile range (IQR) 30-76), largely studying healthy volunteers (29%). Most had high RoB (74%), and only 7% acknowledged potential conflicts from authors' professional ties. No journals appeared on cautionary lists, although 23% of articles were published within 2 months of submission. Only 27% of contactable authors engaged with reviewers. Seven abstracts (12%) were free of spin. Methodological concerns included poor missing data handling (31%), selective analyses (38%), unacknowledged multiple testing (36%), and outcome switching (12%). Meta-analysis found two outliers and five further with very large effects, while 19% provided inadequate data for pooling. Limitations include incomplete reports and lack of validated trustworthiness assessment tools.

CONCLUSION

Adherence to best practices in osteopathic RCTs needs improvement to enhance evidence-based decision-making, reduce research waste, and enhance reproducibility. Further research should explore whether these findings apply to other small, under-resourced fields.

PLAIN LANGUAGE SUMMARY

Clinical trials are studies that test if medical treatments work. Doctors and others use these studies to decide how to care for patients or which treatments should be paid for. For clinical trials to be helpful, they need to follow rules to show they can be trusted. For example, researchers can build trust by sharing their plans before they start, reporting all their results honestly and answering questions about their work. In this project, we looked at 61 clinical trials from a 3.5-year period that tested a hands-on treatment called "osteopathic manual therapy." We checked how well these trials followed the rules for trustworthy research. We found that many trials had problems. For example, important research steps were skipped (such as properly registering the study on appropriate online platforms before starting, following the steps described in the registration documents, and correctly examining the collected data). Often, results were also made to look better than they really are, or it was not clearly explained what happened during the study. Only a few researchers answered questions when we asked them. This shows that some osteopathic trials need to do better so people can trust the results. We also suggest ways researchers can improve trustworthiness in the future.