Meta-analysis of the effects of stuttering treatment.

Despite the many reports of stuttering treatment, there is little consensus either on the long term effectiveness of treatment or on which treatments are the most effective. The literature was searched for treatment outcome studies that reported sufficient data to allow a meta-analysis to be conducted. Forty-two studies covering the treatment of a total of 756 stutterers were located. In these studies the typical client was a 25-year-old severe stutterer who received 80 hours of symptom reduction treatment. Most studies used reliable measures of both stuttering and attitude to assess improvement some six months after treatment had ended. Treatment effects were calculated from 116 pre- and posttreatment pairs of measures. Average effect size was 1.3, which indicates that after treatment the groups of stutterers experienced a 1.3 standard deviation improvement in their pretreatment scores. Clearly, stuttering treatments can be beneficial, and the benefits appear comparable to other treatments in the health sciences. Prolonged speech and gentle onset techniques evidenced better gains in the short term and long term than either attitude or airflow techniques. These four seem preferable to any of the other reported treatments and were certainly better than no treatment.