Can stuttering improve while someone waits for treatment, making treatment appear more effective than it is?

Details

Before-and-after treatment evaluation designs are common in stuttering research. Their validity depends on the assumption that spontaneous remission is unlikely.

The abstract describes six published studies in which people who stutter were assessed twice, some months apart. All six showed a trend toward less stuttering at the second assessment, but none found a statistically significant difference between the scores.

In the present repeated-assessment observational study, 132 people awaiting stuttering treatment were assessed when first seen and again at the start of treatment, 1–23 months later. There was a small but statistically significant improvement between assessments. Its size was comparable to the improvements reported in the six published studies. This spontaneous improvement occurred mainly in the three months after the first assessment, with little change thereafter.

The authors concluded that before-and-after treatment studies of people who had waited more than three months for treatment are valid, and that the improvement observed in those studies can be due solely to treatment effects. Studies measuring improvement from the time people are first seen should account for spontaneous remission to determine the improvement attributable to treatment.