A Systematic Review of Randomized Controlled Trials in the Field of Dysphagia Rehabilitation

Speech Language Pathology interventions in the areas of breathing, chewing, swallowing and speaking: a scoping review

There are several types of approaches that can be used to achieve therapeutic goals in disorders related to the functions of mastication, swallowing, speech, and breathing. However, the literature lacks evidence to support their use in speech-language clinical practice. The objective of this review was to map the syntheses of evidence on speech-language pathology intervention in the areas of breathing, mastication, swallowing and speech in adults and the elderly. Only studies classified by their authors as a systematic review, studies that addressed therapy for orofacial disorders in individuals over 18 years of age were included. The procedures performed included: electronic and manual search; selection of studies; data extraction; evaluation of the quality of studies and data analysis. It was possible to observe different types of interventions mainly aimed at the swallowing function, ranging from traditional therapy to the use of devices. However, due to the limitations of the studies, the data must be interpreted with caution.

Comparing clinical trial population representativeness to real-world populations: an external validity analysis encompassing 43 895 trials and 5 685 738 individuals across 989 unique drugs and 286 conditions in England

BACKGROUND

Randomised controlled trials (RCTs) inform prescription guidelines, but stringent eligibility criteria exclude individuals with vulnerable characteristics, which we define as comorbidities, concomitant medication use, and vulnerabilities due to age. Poor external validity can result in inadequate treatment decision information. Our first aim was to quantify the extent of exclusion of individuals with vulnerable characteristics from RCTs for all prescription drugs. Our second aim was to quantify the prevalence of individuals with vulnerable characteristics from population electronic health records who are actively prescribed such drugs. In tandem, these two aims will allow us to assess the representativeness between RCT and real-world populations and identify vulnerable populations potentially at risk of inadequate treatment decision information. When a vulnerable population is highly excluded from RCTs but has a high prevalence of individuals actively being prescribed the same medication, there is likely to be a gap in treatment decision information. Our third aim was to investigate the use of real-world evidence in contributing towards quantifying missing treatment risk or benefit through an observational study.

METHODS

We extracted RCTs from ClinicalTrials.gov from its inception to April 28, 2021, and primary care records from the Clinical Practice Research Datalink Gold database from Jan 1, 1998, to Dec 31, 2020. We referred to the British National Formulary to classify prescription drugs into drug categories. We conducted descriptive analyses and quantified RCT exclusion and prevalence of individuals with vulnerable characteristics for comparison to identify populations without treatment decision information. Exclusion and prevalence were assessed separately for different age groups, individual clinical specialities, and for quantities of concomitant conditions by clinical specialities, where multimorbidity was defined as having two or more clinical specialties, and medications prescribed, where polypharmacy was defined as having five or more medications prescribed. Population trends of individuals with multimorbidity or polypharmacy were assessed separately by age group. We conducted an observational cohort study to validate the use of real-world evidence in contributing towards quantifying treatment risk or benefit for patients with dementia on anti-dementia drugs with and without a contraindicated clinical speciality. To do so, we identified the clinical specialities that anti-dementia drug RCTs highly excluded yet had corresponding high prevalence in the real-world population, forming the groups with highest risk of having scarce treatment decision information. Cox regression was used to assess if the risk of mortality outcomes differs between both groups.

FINDINGS

43 895 RCTs from ClinicalTrials.gov and 5 685 738 million individuals from primary care records were used. We considered 989 unique drugs and 286 conditions across 13 drug-category cohorts. For the descriptive analyses, the median RCT exclusion proportion across 13 drug categories was 81·5% (IQR 76·7-85·5) for adolescents (aged <18 years), 26·3% (IQR 21·0-29·5) for individuals older than 60 years, 40·5% (IQR 33·7-43·0) for individuals older than 70 years, and 52·9% (IQR 47·1-56·0) for individuals older than 80 years. Multimorbidity had a median exclusion proportion of 91·1% (IQR 88·9-91·8) and median prevalence of 41·0% (IQR 34·9-46·0). Concomitant medication use had a median exclusion proportion of 52·5% (IQR 50·0-53·7) and a median prevalence of 94·3% (IQR 84·3-97·2), and polypharmacy had a median prevalence of 47·7% (IQR 38·0-56·1). Population trends show increasing multimorbidity with age and consistently high polypharmacy across age groups. Populations with cardiovascular or otorhinolaryngological comorbidities had the highest risk of having scarce treatment decision information. For the observational study, populations with cardiovascular or psychiatric comorbidities had highest risk of having scarce treatment decision information. Patients with dementia with an anti-dementia prescription and contraindicated cardiovascular condition had a higher risk of mortality (hazard ratio [HR] 1·20 [95% CI 1·13-1·28 ; p<0·0001]) compared with patients with dementia without a contraindicated cardiovascular condition. Patients with dementia with comorbid delirium (HR 1·25 [95% CI 1·06-1·48]; p<0·0088), intellectual disability (HR 2·72 [95% CI 1·53-4·81]; p=0·0006), and schizophrenia and schizotypal delusional disorders (HR 1·36 [95% CI 1·02-1·82]; p=0·036) had a higher risk of mortality compared with patients with dementia without these conditions.

INTERPRETATION

Overly stringent RCT exclusion criteria do not appropriately account for the heterogeneity of vulnerable characteristics observed in real-world populations. Treatment decision information is scarce for such individuals, which might affect health outcomes. We discuss the challenges facing the inclusivity of such individuals and highlight the strength of real-world evidence as an integrative solution in complementing RCTs and increasing the completeness of evidence-based medicine assessments in evaluating the effectiveness of treatment decisions.

FUNDING

Wellcome Trust, National Institute for Health Research (NIHR) University College London Hospitals Biomedical Research Centre, NIHR Great Ormond Street Hospital Biomedical Research Centre, Academy of Medical Sciences, and the University College London Overseas Research Scholarship.

Does Etiology Matter? Comparative Analysis of a Singing-Enhanced Swallowing Protocol for Patients with Neurological Impairment versus Head and Neck Cancer

Swallowing difficulties are a common complaint among patients with a variety of diseases. To address these concerns, a singing-enhanced swallowing protocol was constructed, and its differential benefits for two patient populations were investigated. Two patients with Parkinson’s disease (PD) and two patients with head and neck cancer (HNC) participated in this study. Each patient participated in 30-min individual sessions of a singing-enhanced swallowing protocol two times per week for 12 weeks. Following the intervention, laryngeal diadochokinesis and quality-of-life measurements were found to be higher in all four patients. However, the Videofluoroscopic Dysphagia Scale showed this improvement was associated with different swallowing tasks for each patient group. In addition, the maximum phonation time decreased for patients with HNC, while it increased for patients with PD. The findings support the use of a singing-enhanced swallowing protocol for patients whose swallowing difficulties are due to neurological or structural impairment. In addition, the study results suggest that different intervention components should be considered depending on the etiology of the patient’s swallowing difficulties.

Transcutaneous Electrical Stimulation and Dysphagia Rehabilitation: A Narrative Review

Transcutaneous electrical stimulation (TES) was introduced as a modality for dysphagia rehabilitation more than a decade ago. The underlying premise of this modality is improving the structural movements and enhancing neural activation based on stimulation-induced muscle contractions. However, divisive evidence exists regarding the effectiveness of this treatment modality. This manuscript reviews current evidence regarding the effects of transcutaneous electrical stimulation (TES) on clinical and physiological aspects of swallowing function. Furthermore, this narrative review delineates the knowledge gap in this area and recommends future research roadmap. This review gives a comprehensive picture regarding current knowledge of TES to practicing speech and language pathologists and interested researchers. It highlights the need for more robust studies in this area. It also encourages researchers to focus more on the physiologic studies to understand the physiologic underpinning behind this treatment modality.

Exercise-based swallowing intervention (McNeill Dysphagia Therapy) with adjunctive NMES to treat dysphagia post-stroke: A double-blind placebo-controlled trial

BACKGROUND

Dysphagia following stroke is prevalent; however, dysphagia treatment is often applied haphazardly and outcomes unclear. Neuromuscular electrical stimulation (NMES) has received increased attention as a treatment for post-stroke dysphagia; but application data remain conflicted.

OBJECTIVE

This study investigated effectiveness and safety of an exercise-based swallowing therapy (McNeill Dysphagia Therapy: MDTP) +NMES for dysphagia rehabilitation following stroke.

METHODS

Stroke patients (n = 53, x̅ age: 66 [13.2], 47.2% male) with dysphagia admitted to sub-acute rehabilitation hospital were randomised to MDTP + NMES [NMES], MDTP + sham NMES [MDTP] or usual care [UC] swallowing therapy groups. Patients were treated for 1 hour per day for 3 weeks and monitored to 3 months by a blinded evaluator. Outcomes included clinical swallowing ability, oral intake, weight, patient perception of swallow and occurrence of dysphagia-related complications.

RESULTS

Post-treatment dysphagia severity and treatment response were significantly different between groups (P ≤ .0001). MDTP demonstrated greater positive change than either NMES or UC arms, including increase in oral intake (χ²  = 5, P ≤ .022) and improved functional outcome by 3 months post-stroke (RR = 1.72, 1.04-2.84). Exploratory Cox regression revealed the MDTP group conferred the greatest benefit in time to "return to pre-stroke diet" of 4.317 [95% CI: 1.08- 17.2, P< .03].

CONCLUSION

Greater benefit (eg reduction in dysphagia severity, improved oral intake and earlier return to pre-stroke diet) resulted from a programme of MDTP alone vs NMES or UC.

Use of modified diets to prevent aspiration in oropharyngeal dysphagia: is current practice justified?

BACKGROUND

Although modifying diets, by thickening liquids and modifying the texture of foods, to reduce the risk of aspiration has become central to the current management of dysphagia, the effectiveness of this intervention has been questioned. This narrative review examines, and discusses possible reasons for, the apparent discrepancy between the widespread use of modified diets in current clinical practice and the limited evidence base regarding the benefits and risks of this approach.

DISCUSSION

There is no good evidence to date that thickening liquids reduces pneumonia in dysphagia and this intervention may be associated with reduced fluid intake. Texture-modified foods may contribute to undernutrition in those with dysphagia. Modified diets worsen the quality of life of those with dysphagia, and non-compliance is common. There is substantial variability in terminology and standards for modified diets, in the recommendations of individual therapists, and in the consistency of diets prepared by healthcare staff for consumption. Although use of modified diets might appear to have a rational pathophysiological basis in dysphagia, the relationship between aspiration and pneumonia is not clear-cut. Clinical experience may be a more important determinant of everyday practice than research evidence and patient preferences. There are situations in the management of dysphagia where common sense and the necessity of intervention will clearly outweigh any lack of evidence or when application of evidence-based principles can enable good decision making despite the absence of robust evidence. Nevertheless, there is a significant discrepancy between the paucity of the evidence base supporting use of modified diets and the beliefs and practices of practitioners.

CONCLUSION

The disconnect between the limited evidence base and the widespread use of modified diets suggests the need for more careful consideration as to when modified diets might be recommended to patients. Patients (or their representatives) have a choice whether or not to accept a modified diet and must receive adequate information, about the potential risks and impact on quality of life as well as the possible benefits, to make that choice. There is an urgent need for better quality evidence regarding this intervention.

Behaviour change technique taxonomy: a method of describing head and neck cancer dysphagia intervention delivery

PURPOSE OF REVIEW

The purpose of the review is to examine the current state of the art of dysphagia intervention delivery description and to propose use of a new tool to facilitate this: the behaviour change technique taxonomy version 1 (BCTTv1).

RECENT FINDINGS

Describing intervention delivery is difficult, and published research in the field of speech and language therapy (SLT) does not include detail on this key aspect of research protocols. Interventions themselves are often poorly delineated, and a way is needed of classifying how these interventions are delivered in practice.

SUMMARY

Use of the BCTTv1 would facilitate clarity and transparency in intervention delivery description and have positive implications for research, clinical practice and undergraduate teaching if employed by the SLT profession.

Swallowing interventions for the treatment of dysphagia after head and neck cancer: a systematic review of behavioural strategies used to promote patient adherence to swallowing exercises

BACKGROUND

Dysphagia is a significant side-effect following treatment for head and neck cancers, yet poor adherence to swallowing exercises is frequently reported in intervention studies. Behaviour change techniques (BCTs) can be used to improve adherence, but no review to date has described the techniques or indicated which may be more associated with improved swallowing outcomes.

METHODS

A systematic review was conducted to identify behavioural strategies in swallowing interventions, and to explore any relationships between these strategies and intervention effects. Randomised and quasi-randomised studies of head and neck cancer patients were included. Behavioural interventions to improve swallowing were eligible provided a valid measure of swallowing function was reported. A validated and comprehensive list of 93 discrete BCTs was used to code interventions. Analysis was conducted via a structured synthesis approach.

RESULTS

Fifteen studies (8 randomised) were included, and 20 different BCTs were each identified in at least one intervention. The BCTs identified in almost all interventions were: instruction on how to perform the behavior, setting behavioural goals and action planning. The BCTs that occurred more frequently in effective interventions, were: practical social support, behavioural practice, self-monitoring of behaviour and credible source for example a skilled clinician delivering the intervention. The presence of identical BCTs in comparator groups may diminish effects.

CONCLUSIONS

Swallowing interventions feature multiple components that may potentially impact outcomes. This review maps the behavioural components of reported interventions and provides a method to consistently describe these components going forward. Future work may seek to test the most effective BCTs, to inform optimisation of swallowing interventions.

Therapeutic intervention in oropharyngeal dysphagia

Oropharyngeal dysphagia is a frequent consequence of several medical aetiologies, and even considered part of the normal ageing process. Early and accurate identification provides the opportunity for early implementation of dysphagia treatments. This Review describes the current state of the evidence related to dysphagia therapies - focusing on treatments most clinically utilized and of current interest to researchers. Despite successes in select studies, the level of evidence to support the efficacy of these treatments remains limited. Heterogeneity exists across studies in both how interventions are administered and how their therapeutic value is assessed, thereby making it difficult to establish external validation. Future work needs to address these caveats. Also, to be most efficacious, dysphagia therapies need to account for influences from pre-morbid patient characteristics as these factors have potential to increase the risk of dysphagia and the resulting complications of aspiration, malnutrition and psychological burden. Dysphagia therapies therefore need to incorporate the medical aetiology that is at its root, the resulting swallow physiology captured from comprehensive clinical and/or instrumental assessments, and the existing needs and supports of patients.

Identification of behaviour change components in swallowing interventions for head and neck cancer patients: protocol for a systematic review

BACKGROUND

Dysphagia (difficulty in swallowing) is a predictable consequence of head and neck cancer and its treatment. Loss of the ability to eat and drink normally has a devastating impact on quality of life for survivors of this type of cancer. Most rehabilitation programmes involve behavioural interventions that include swallowing exercises to help improve swallowing function. Such interventions are complex; consisting of multiple components that may influence outcomes. These interventions usually require patient adherence to recommended behaviour change advice. To date, reviews of this literature have explored whether variation in effectiveness can be attributed to the type of swallowing exercise, the use of devices to facilitate use of swallowing muscles, and the timing (before, during or after cancer treatment). This systematic review will use a behavioural science lens to examine the content of previous interventions in this field. It aims to identify (a) which behaviour change components are present, and (b) the frequency with which they occur in interventions deemed to be effective and non-effective.

METHODS/DESIGN

Clinical trials of behavioural interventions to improve swallowing outcomes in patients with head and neck cancers will be identified via a systematic and comprehensive search of relevant electronic health databases, trial registers, systematic review databases and Web of Science. To ascertain behaviour change intervention components, we will code the content for its theory basis, intervention functions and specific behaviour change techniques, using validated tools: the Theory Coding Scheme, Behaviour Change Wheel and Behaviour Change Technique Taxonomy v1. Study quality will be assessed for descriptive purposes only. Given the specialisation and focus of this review, a small yield of studies with heterogeneous outcome measures is anticipated. Therefore, narrative synthesis is considered more appropriate than meta-analysis. We will also compare the frequency of behavioural components in effective versus non-effective interventions, where effectiveness is indicated by statistically significant changes in swallowing outcomes.

DISCUSSION

This review will provide a synthesis of the behaviour change components in studies that currently represent best evidence for behavioural swallowing interventions for head and neck cancer patients. Results will provide some guidance on the choice of optimal behavioural strategies for the development of future interventions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015017048.