Non-Interventional Factors Influencing Velopharyngeal Function For Speech In Initial Cleft Palate Repair: A Systematic Review Protocol

BACKGROUND: This systematic review aims to inform the development of a screening tool which pre-operatively predicts which children are likely to develop velopharyngeal insufficiency, one of the causes of poor speech outcomes, following cleft palate repair. This would be highly beneficial as it would inform pre-operative counselling of parents, allow targeted speech and language therapy, and enable meaningful comparison of outcomes between surgeons, techniques, and institutions. Currently, it is unclear which factors influence speech outcomes. A systematic review investigating the non-interventional factors which potentially influence speech outcomes following cleft palate repair is warranted. This may be illuminating in itself or provide foundations for future studies. METHODS: A systematic review will be carried out according to Cochrane methodology and reported according to PRISMA guidelines (PLoS Med 6: e1000097, 2009). Systematic review software will be used to facilitate three-stage screening by two independent reviewers experienced in cleft lip and palate. Thereafter, data extraction and GRADE assessment will be performed in duplicate by five independent reviewers experienced in cleft lip and palate. Studies reporting the proportion of patients who were recommended or underwent secondary speech surgery for velopharyngeal insufficiency following primary surgery for cleft palate will be included. The study findings will be tabulated and summarised. The primary outcome measure will be further speech surgery (either recommended or performed). The secondary outcome measure will be perceptual speech assessment for the presence of velopharyngeal insufficiency. A meta-analysis is planned. However, if this is not possible, due to the anticipated marked heterogeneity of study characteristics, pre-operative assessment, and the recorded outcome measures, a narrative synthesis will be undertaken. DISCUSSION: This systematic review may provide sufficient data to inform the development of a screening tool to predict the risk of velopharyngeal insufficiency prior to cleft palate repair. However, it is anticipated that these findings will provide the foundation for future studies in this area. SYSTEMATIC REVIEW REGISTRATION: Registered on 19 December 2016 with PROSPERO CRD42017051624