Core Outcome Measures in Effectiveness Trials

Identification of a core outcome set for reporting outcomes of surgery for velopharyngeal dysfunction

General Information

The velopharyngeal sphincter is critically important during speech because it airflow into the nasal part of the vocal tract. Velopharyngeal speech disorder (VPD) refers to inadequate closure of the velopharyngeal sphincter during speech, resulting in hypernasal resonance, inappropriate nasal emission of air (either inaudible or audible as nasal friction or turbulence) and decreased intraoral pressure for oral pressure consonants. The overall result is decreased intelligibility of speech and significant functional and social impairment.

The velopharyngeal sphincter may fail for structural reasons such as overt or submucous cleft palate or a repaired cleft palate that remains short or immobile due to surgical scarring or abnormally positioned palatal muscles. VPD is present in 5-20% of patients following cleft palate repair. While speech therapy may help to correct articulation placement errors secondary to VPD, correction of a structurally or neuromuscularly incompetent velopharyngeal port requires a physical intervention, most commonly surgery.

The aim of surgical intervention in VPD is to create a functional seal between the nasopharynx and the oropharynx during speech, whilst avoiding nasal airway obstruction. Surgical interventions can be divided into three broad categories – palate muscle repositioning, pharyngoplasty procedures and posterior pharyngeal wall augmentation

We recently carried out a systematic review of the literature and found that while the surgical options in the management of VPD are numerous, the literature lacks prospective comparative series. The most consistently reported outcomes across the studies included in our review were various speech assessment measures, the presence of postoperative obstructive sleep apnoea (OSA) and the need for further surgery. Perceptual speech assessment scales varied widely between studies, with the minority using previously published, validated perceptual speech assessment scales. Reporting of OSA also varied widely across the included studies. . Furthermore, and indeed most crucially, none of the studies included a formal patient reported outcome measure in their results. Finally it was noted that there was a significant heterogeneity in the selection of patients included in the studies.

In summary, it appears that researchers have traditionally reported outcomes using diverse parameters, particularly with regard to perceptual speech assessment. Given that randomized controlled trials of surgical interventions are fraught with difficulty, research in to VPD surgery is likely to continue to comprise of cohort studies and retrospective case series. The aim of the current study is to engage the multidisciplinary VPD community and to develop a universally applicable, standardized minimum dataset to record postoperative speech, sleep apnea and patient reported outcomes. Such an instrument would reduce both outcome reporting bias and heterogeneity between studies, thus allowing meaningful collation of results across multiple institutions.

David Orr, Consultant Plastic Surgeon, Dublin Cleft Centre, Our Lady's Children's Hospital Crumlin, Trinity College Dublin Ireland (Principle Investigator, Project Supervisor)

Catherine de Blacam, Plastic Surgery Registrar, Dublin Cleft Centre, Our Lady's Children's Hospital Crumlin

Adriane Baylis, Speech and Language Pathologist, Nationwide Children's Hospital, Columbus Ohio, USA

Richard Kirchner, Attending Plastic Surgeon, Nationwide Children's Hospital, Columbus Ohio, USA

Further Study Information

Current Stage:
September 2018 - September 2020
Funding source(s):

Health Area

Disease Category
Child health

Disease Name
Velopharyngeal speech disorder

Target Population

Age Range


Nature / type of Intervention


Consensus meeting
Delphi process
Focus group(s)
Nominal group technique (NGT)
Semi structured discussion
Systematic review

In brief, an expert panel will be convened to identify a list of potential core outcomes on the basis of a previously published systematic review of the literature pertaining to the topic. Input will be sought from the wider community of clinicians who provide care for patients with VPD via a Delphi survey process. Public and patient involvement will be facilitated by focus group discussions and interviews. The expert panel will reconvene at a consensus meeting to agree the final COS.

Stakeholders Involved

Clinical experts
Conference participants
Consumers (caregivers)
Consumers (patients)
Patient/ support group representatives
Service providers
Service users

Study Type

COS for clinical trials or clinical research
COS for practice

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