PO:38:285 | Cross-sectional analysis: interpretation of nonstatistically significant results in randomised controlled clinical trials in rehabilitation

Caterina Mugnai¹, Luca Falsiroli Maistrello^2|3|4, Giacomo Fiacca³, Michele Perrucchini³, Noemi Corbetta³, Federico Amateis³, Stefano Salvioli³ | ¹University of Ferrara; ²ULSS 9 Scaligera, Department of Physical Medicine and Rehabilitation, G. Fracastoro Hospital, San Bonifacio ^VR; ³Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa; ⁴School of Physiotherapy, Department of Neuroscience, Biomedicine and Movement, University of Verona, Italy

Objectives: to assess the prevalence of misinterpretation of non-statistically significant results, both in the abstract and in the article conclusions, in a sample of randomised controlled trials with nonstatistically significant primary outcomes published in rehabilitation journals and reporting of primary outcomes according to CONSORT guidelines.

Methods: a cross-sectional analysis of all randomised controlled trials with non- statistically significant primary outcomes in 5 general rehabilitation journals with the highest Impact Factor published between 2019 and 2023 to determine the prevalence of trials in which non-significance was interpreted as absence of evidence, evidence of absence, or advice to use the intervention in clinical practice in the abstract and article conclusions, and the prevalence of trials that adhered to CONSORT guidelines for reporting the primary outcome.

Results: at the end of the selection process, 31 trials were included. The most common interpretation of non-statistically significant results is the evidence of absence, both in the abstract (74.2%) and in the article (58.1%). Only 4 (12.9%) studies in the abstract and 5 (16.1%) in the article conclusions suggest the correct interpretation as absence of evidence. Adherence to CONSORT guidelines for reporting primary outcomes was moderate, with only 61.3% of trials reporting summaries of results for each arm, effect size and confidence interval.

Conclusions: There is the need for increased rigor in reporting and interpreting non statistically significant results in rehabilitation trials. Evidence misinterpretations can adversely impact clinical decision-making and future research directions. Efforts should be made to promote accurate interpretation of statistical results, emphasize the importance of reporting and analysing effect sizes and confidence intervals, and develop educational interventions to improve statistical literacy.