A study of respiratory sinus arrhythmia and stuttering persistence.

The persisting group contained only 10 children, so the study had low statistical power for detecting differences in that group. The paper reports 66 children meeting group criteria but also says 17 additional participants were excluded because of ECG recording issues, and the final number analysed for each condition is not clear from the text. The text lists several exclusion and attrition reasons, including a 28.6% attrition rate among children who qualified but did not complete the study. Two children in the persisting group and six in the recovered group received stuttering treatment during the study, and the treatment type was not reported, so the contribution of treatment cannot be separated from natural recovery or persistence. The sample was restricted to children with no known speech or language disorder other than stuttering and typical hearing, neurological, intellectual, and social development, so findings may not apply to children with co-occurring conditions. RSA was measured only at the initial time point, and the study did not test whether individual stuttering moments were associated with RSA changes. The effect of talking duration on respiration and RSA remains unclear, which may affect interpretation of RSA during speaking tasks.

The supplied text lists research support from NIH extramural and non-U.S. government sources. It does not include an author conflict-of-interest declaration.

Do not conclude that breathing-linked heart-rate variability predicts which children will continue to stutter. Baseline RSA did not differ between the persisting, recovered, and non-stuttering groups, and the task-specific differences came from a small sample with 10 persisting children.