Spin in randomized clinical trials evaluating quality of life after third molar extraction: a meta-research study

The aim of this study was to evaluate the prevalence of spin and associated factors in randomized controlled trials (RCTs) assessing quality of life after third molar extraction. This meta-research followed meta-epidemiological guidelines and included RCTs reporting quality of life outcomes after third molar surgery, regardless of statistical significance. Searches were conducted in 11 databases up to March 2025. Spin was assessed in abstracts, main texts, and conclusions, and categorized as low (<25%), moderate (25-75%), or high (>75%). Of 4093 citations, 42 articles met inclusion criteria. Most reported statistically significant results. Overall, spin was infrequent, occurring in 9.5% of abstracts and full texts. The omission of adverse events was the most common pattern, observed in 85.7% of abstracts and 47.6% of full texts, potentially leading readers to overestimate the benefits of treatment and underestimate associated risks. This underreporting, particularly in abstracts, may misinform clinical decision-making and patient counselling. Spin was highly prevalent in the results sections of abstracts (88.1%). No significant associations were found between spin, CONSORT adherence, or study and journal characteristics (P ≥ 0.05). Spin was uncommon in RCTs evaluating quality of life after third molar extraction, especially in conclusions. However, when present, it was often substantial, highlighting the need for improved transparency in scientific reporting.