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Interventions for preventing voice disorders in adultsRuotsalainen JH, Sellman J, Lehto L, Jauhiainen M, Verbeek JH
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SummaryInterventions for preventing voice disorders in adultsPeople in occupations where voice use is central, such as teachers, are more at risk of developing voice disorders. The definition of voice disorders and their possible causes as well as the best methods for preventing them are still being debated. There is also no consensus on the best method of evaluating the voice, although many consider auditory voice quality assessment as a gold standard measure. Voice training is used both in treatment and in (secondary) prevention of voice disorders. Voice training usually consists of a combination of direct and indirect treatment techniques. Direct techniques focus on the underlying physiological changes needed to improve an individual's technique in using the vocal system whereas indirect techniques concentrate on contributory and maintenance aspects of the voice disorder (such as lack of knowledge). We conducted a systematic search of the literature on preventing voice disorders in adults. We then appraised the quality of the studies found and combined their results. We found two studies which met our inclusion criteria. One was conducted with teachers and the other with student teachers. We found no evidence that either direct or indirect voice training nor the two combined are effective in improving vocal functioning when compared to no intervention. Both studies were small and of low methodological quality. Given the extent of the problem and the widespread use of training further research is warranted.
This is a Cochrane review abstract and plain language summary, prepared and maintained by The Cochrane Collaboration, currently published in The Cochrane Database of Systematic Reviews 2010 Issue 1, Copyright © 2010 The Cochrane Collaboration. Published by John Wiley and Sons, Ltd.. The full text of the review is available in The Cochrane Library (ISSN 1464-780X).
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October 17. 2007 AbstractBackgroundPoor voice quality due to a voice disorder can lead to a reduced quality of life. In occupations where voice use is substantial it can lead to periods of absence from work. ObjectivesTo evaluate the effectiveness of interventions to prevent voice disorders in adults. Search strategyWe searched MEDLINE (PubMed, 1950 to 2006), EMBASE (1974 to 2006), CENTRAL (The Cochrane Library, Issue 2 2006), CINAHL (1983 to 2006), PsychINFO (1967 to 2006), Science Citation Index (1986 to 2006) and the Occupational Health databases OSH-ROM (to 2006). The date of the last search was 05/04/06. Selection criteriaRandomised controlled clinical trials (RCTs) of interventions evaluating the effectiveness of treatments to prevent voice disorders in adults. For work-directed interventions interrupted time series and prospective cohort studies were also eligible. Data collection and analysisTwo authors independently extracted data and assessed trial quality. Meta-analysis was performed where appropriate. Main resultsWe identified two randomised controlled trials including a total of 53 participants in intervention groups and 43 controls. One study was conducted with teachers and the other with student teachers. Both trials were poor quality. Interventions were grouped into 1) direct voice training, 2) indirect voice training and 3) direct and indirect voice training combined. 1) Direct voice training: One study did not find a significant decrease of the Voice Handicap Index for direct voice training compared to no intervention. 2) Indirect voice training: One study did not find a significant decrease of the Voice Handicap Index for indirect voice training when compared to no intervention. 3) Direct and indirect voice training combined: One study did not find a decrease of the Voice Handicap Index for direct and indirect voice training combined when compared to no intervention. The same study did however find an improvement in maximum phonation time (Mean Difference -3.18 sec; 95 % CI -4.43 to -1.93) for direct and indirect voice training combined when compared to no intervention. No work-directed studies were found. None of the studies found evaluated the effectiveness of prevention in terms of sick leave or number of diagnosed voice disorders. Authors' conclusionsWe found no evidence that either direct or indirect voice training or the two combined are effective in improving self-reported vocal functioning when compared to no intervention. The current practice of giving training to at-risk populations for preventing the development of voice disorders is therefore not supported by definitive evidence of effectiveness. Larger and methodologically better trials are needed with outcome measures that better reflect the aims of interventions. |