Meta-analysis of Stuttering Prevalence and Incidence

Objectives: Stuttering prevalence and incidence can be measured in very diverse ways and such differences in methodologies may contribute to variability of the results. Moreover stuttering prevalence and incidence can be different according to factors such as gender and age. The current study tried to provide a comprehensive view on stuttering prevalence and incidence through meta-analysis of the research results. We also tried to determine whether stuttering prevalence and incidence would be different according to gender, age, and region. Methods: A total of four databases (two Korean and two English databases) were used in the current study for article search. A total of 27 articles (26 English, 1 Korean) met the inclusion/exclusion criteria and were analyzed in the current study. Results: Overall stuttering prevalence was about 1.5% and overall stuttering incidence was about 3.9%. There was a statistically significant difference in stuttering prevalence according to gender and age. Stuttering prevalence for males and preschoolers was almost twice as much as that of females and other age groups. However there was no significant difference in prevalence according to regions. Furthermore there was no significant difference in stuttering incidence according to gender. Conclusion: The meta-analysis results of the current study showed very similar, but still somewhat different stuttering prevalence and incidence compared to the commonly held belief. Such differences may be due to the typical characteristics of the studies analyzed in the current study. There may be future studies on more diverse factors that influence stuttering prevalence and incidence.