CRD summary

This review found no evidence of positive results from the pharmacological treatment of stuttering. The review had methodological and reporting limitations but, overall, the authors’ conclusions are in line with the evidence presented and seem appropriate.

Authors' objectives

To review the effectiveness of pharmacological treatments for stuttering.

Searching

MEDLINE, Web of Science, PsycINFO and ComDisDome were searched from 1970 to 2005 for articles published in English; the search terms used were reported (see Other Publications of Related Interest). Articles were also identified through personal libraries, previously compiled reference lists and handsearches of four specialist journals.

Study selection

Assessment of study quality

Studies were evaluated against five methodological criteria covering study design, blinded data collection, data from before and after treatment, data from beyond-clinic conditions, and data about speech rate, speech naturalness and observer agreement if claims were made about stuttering frequency or severity. Studies were also assessed using the Oxford Centre for Evidence-Based Medicine’s levels of evidence and grades of recommendation, and Chambless and Hollon’s criteria for identifying empirically supported therapies.

The authors did not state how many reviewers performed the validity assessment.

Data extraction

Two independent reviewers extracted the data, with any disagreements resolved by consensus.

Methods of synthesis

Results of the review

Thirty-five ‘units of analysis’ (an evaluation of one drug or combination represented a unit of analysis) reported in 31 publications were included. The total number of participants was not provided.

Of the 35 units of analysis, 5 met none of the methodological quality criteria, 11 met one, 6 met two and 13 met three. One study found that stuttering frequency was reduced to below 5% by risperidone. Haloperidol (2 studies), propanolol [sic] and sertraline were reported to have reduced stuttering by at least half. Botulinum toxin injections (1 study), clomipramine and desipramine (2 studies each) and carbamazepine (1 study) were reported to be associated with improvements in SEC variables. However, some of these positive results came from studies that met fewer than three methodological quality criteria and the others were considered to be compromised by other factors (e.g. unusually good outcome in placebo group, contradiction by other studies of the same drug, or lack of an untreated control group).

Authors' conclusions

None of the included studies met basic methodological criteria. The best available studies showed few, if any, uncomplicated reports of positive results from the pharmacological treatment of stuttering.

CRD commentary

This review addressed a clear question and had clear inclusion criteria for the participants and interventions. Inclusion criteria for the outcomes were broad and it appears that all types of study design were eligible. The authors searched a range of relevant sources, although the search was restricted to English language material and hence some relevant studies could have been missed. Unpublished studies were not sought and publication bias was not assessed, so the review could be at risk of publication bias. Study quality was assessed and the results were used in the synthesis. It appears that appropriate methods were used to minimise errors and bias during the review process. However, details of the included studies (other than the drug used) were not systematically reported; this makes it difficult to comment on the strength of the evidence and generalisability of the review findings.

A narrative synthesis was presented, which appears appropriate in view of the variety of included interventions and study designs. In spite of the reporting limitations of the review, the authors’ conclusions are in line with the evidence presented and seem appropriate.

Implications of the review for practice and research

Practice: The authors stated that none of the pharmacological agents tested can be recommended to clinicians or patients.

Research: The authors stated that issues such as participant selection and attrition should be considered in future trials, and that well-designed comparisons between pharmacological approaches and other speech therapy approaches may be necessary.

Funding

National Institutes of Health, grant number R01-004638.

Bibliographic details

Bothe A K, Davidow J H, Bramlett R E, Franic D M, Ingham R J. Stuttering treatment research 1970-2005 - II: systematic review incorporating trial quality assessment of pharmacological approaches. American Journal of Speech-Language Pathology 2006; 15(4): 342-352. [PubMed: 17102145]

Other publications of related interest

Bothe AK, Davidow JH, Bramlett RE, Franic DM, Ingham RJ. Stuttering treatment research 1970-2005: I. Systematic review incorporating trial quality assessment of behavioural, cognitive and related approaches. Am J Speech Lang Pathol 2006;15:321-41.

Indexing Status

Subject indexing assigned by NLM

MeSH

Anticonvulsants /therapeutic use; Antidepressive Agents /therapeutic use; Antipsychotic Agents /therapeutic use; Cardiovascular Agents /therapeutic use; Clinical Trials as Topic /standards; Dopamine Antagonists /therapeutic use; Evidence-Based Medicine; Humans; Research; Research Design /standards; Stuttering /drug therapy; Treatment Outcome

AccessionNumber

12007005255

Database entry date

09/08/2008

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.