Swallowingtherapyfordysphagiainacuteandsubacute stroke ...Main results We added 27 new studies (1777 participants) to this update to include a total of 41 trials (2660 participants).

D I S C U S S I O N

Summary of main results

We included 41 studies in this updated review of swallowing ther-

apy in people with stroke We identified 22 additional studies that

are ongoing (Characteristics of ongoing studies) along with 86

studies that are awaiting classification (Characteristics of studies

awaiting classification)

Researchers assessed eight types of stimulatory techniques -

acupuncture behavioural therapy drug therapy neuromuscular

electrical stimulation (NMES) pharyngeal electrical stimulation

(PES) physical stimulation transcranial direct current stimula-

tion (tDCS) and transcranial magnetic stimulation (TMS) Swal-

lowing therapy had no effect on functional outcomes (death or de-

pendency or death or disability) although only one trial reported

this outcome (two data sets) Swallowing therapy also had no ef-

fect on case fatality at end of trial nor on penetration aspiration

score However swallowing therapy probably reduced length of

inpatient stay the proportion of participants with dysphagia at end

of trial and the incidence of chest infection or pneumonia (with

one study reporting significant effects for drug therapy) Swallow-

ing therapy also probably improved swallowing ability In the ab-

sence of significant effects on the primary outcome statistically

significant findings in secondary and explanatory outcomes are

hypothesis-generating and might reflect chance for example due

to multiple-comparison testing Hence further trials are needed

to test these observations

Overall completeness and applicability ofevidence

Results of this review are incomplete at this time because of the

significant number of ongoing studies and those awaiting classi-

fication identified by review authors Nevertheless the addition

of new studies to this version of the review has tightened con-

fidence intervals although the overall conclusion that dysphagia

treatment does not alter functional outcome has not changed

Quality of the evidence

The quality of evidence ranged from very low and low through

moderate to high as presented in Summary of findings for the

main comparison The most common reasons for reduced quality

of evidence were lack of blinding moderate to considerable het-

erogeneity between trials and lack of precision (ie inclusion of

multiple different interventions)

Potential biases in the review process

Results of the present analysis are subject to several caveats First

we combined different interventions together for analysis to assess

whether trial results show any effect of swallowing therapy as a

whole as opposed to no intervention or usual care This means that

decisions on which specific types of interventions are effective can-

not be made upon analysis of these data Future reviews will focus

on assessing effects of specific interventions on main outcomes

Second we excluded 80 studies from the analysis One common

reason for exclusion is that studies compared two active treatments

without including a control or placebo group We also excluded

trials due to lack of uniformity in usage of outcome measures and

lack of data on clinical outcomes such as dependency mortality

institutionalisation and chest infection or pneumonia Further

included trials used various swallowing assessment techniques cor-

tical excitability techniques and videofluoroscopic measurements

So trialists are encouraged to design future trials that include a

control or placebo group and to incorporate standard outcome

measures Third a further 86 studies are awaiting assessment sub-

ject to the availability of full-text articles such omission of multi-

ple studies will inevitably bias review results Fourth with regard to

acupuncture data from three studies may have been confounded

due to use of rsquoroutinersquo acupuncture or a different type of acupunc-

ture as control variation in delivery of therapy and risk of lan-

guage bias in that some of the acupuncture literature is available

in full only in Chinese language journals Similarly we included

data from an NMES study (Park 2012) which considered sensory

stimulation as a control therefore we cannot be certain that this

trial is not confounded Last the present analysis included only

studies up to six months from stroke onset and the effects of later

treatments for post-stroke dysphagia remain unclear

It is important to note that many trials are ongoing and should

add substantially to the existing data once complete

Agreements and disagreements with otherstudies or reviews

This is the largest most inclusive and most up-to-date review on

this topic It combines all current interventions for dysphagia in the

acute and subacute phases of stroke A number of separate system-

atic reviews exploring individual interventions for stroke survivors

have been published including some examining acupuncture in

stroke (Xie 2008 Long 2012 Wong 2012) behavioural interven-

tions in neurogenic dysphagia (Ashford 2009) TMS in stroke and

acquired brain injury (Yang 2015 Liao 2016 Momosaki 2016

Pisegna 2016) tDCS in stroke and acquired brain injury (Yang

2015 Momosaki 2016 Pisegna 2016) NMES in stroke and neu-

rological impairment (Chen 2016 Ding 2016) and PES in stroke

(Scutt 2015) However these reviews have examined the efficacy

of individual interventions whereas the current review has exam-

ined the efficacy of swallowing therapy overall hence direct com-

17Swallowing therapy for dysphagia in acute and subacute stroke (Review)

Copyright copy 2018 The Cochrane Collaboration Published by John Wiley amp Sons Ltd