Causality and Speech, Language and Hearing Sciences: epidemiological approach

To review the Speech-Language Pathology literature studies from the epidemiology and causality perspective.

A national and international literature survey was carried out with searches from PubMed, SciELO and gray literature bases, conducted according to the instructions of the Cochrane Collaboration and published until January 9th, 2019. The review guiding question asks if Speech-Language Pathology uses methods in their evidence to infer causality.

All studies that presented a causal epidemiological approach in speech therapy were included, as well as excluded those that did not present an appropriate methodological approach for cause and effect analysis.

Two authors of this study independently reviewed all citations. A priori determined form was used to extract the following data: author, year of publication, country of origin, theoretical conception, application or not of the study and central discussion addressed in the article.

From the search performed 3842 articles were found. However, none of them investigated their outcomes from the causality point of view, not allowing cause and effect inference.

There is a shortage of studies that evidence causality in Speech-Language Pathology, which may alter the effectiveness and reliable handling of diagnosis and speech-language therapy, since it is still based on association and not on cause and effect based on studies designed to that.