Swallowing therapy for dysphagia in acute and subacute stroke

Dysphagia (swallowing problems), which is common after stroke, is associated with increased risk of death or dependency, occurrence of pneumonia, poor quality of life, and longer hospital stay. Treatments provided to improve dysphagia are aimed at accelerating recovery of swallowing function and reducing these risks. This is an update of the review first published in 1999 and updated in 2012.

To assess the effects of swallowing therapy on death or dependency among stroke survivors with dysphagia within six months of stroke onset.

We searched the Cochrane Stroke Group Trials Register (26 June 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 6) in the Cochrane Library (searched 26 June 2018), MEDLINE (26 June 2018), Embase (26 June 2018), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (26 June 2018), Web of Science Core Collection (26 June 2018), SpeechBITE (28 June 2016), ClinicalTrials.Gov (26 June 2018), and the World Health Organization International Clinical Trials Registry Platform (26 June 2018). We also searched Google Scholar (7 June 2018) and the reference lists of relevant trials and review articles.

We sought to include randomised controlled trials (RCTs) of interventions for people with dysphagia and recent stroke (within six months).

Two review authors independently applied the inclusion criteria, extracted data, assessed risk of bias, used the GRADE approach to assess the quality of evidence, and resolved disagreements through discussion with the third review author (PB). We used random-effects models to calculate odds ratios (ORs), mean differences (MDs), and standardised mean differences (SMDs), and provided 95% confidence intervals (CIs) for each.The primary outcome was functional outcome, defined as death or dependency (or death or disability), at the end of the trial. Secondary outcomes were case fatality at the end of the trial, length of inpatient stay, proportion of participants with dysphagia at the end of the trial, swallowing ability, penetration aspiration score, or pneumonia, pharyngeal transit time, institutionalisation, and nutrition.

We added 27 new studies (1777 participants) to this update to include a total of 41 trials (2660 participants).We assessed the efficacy of swallowing therapy overall and in subgroups by type of intervention: acupuncture (11 studies), behavioural interventions (nine studies), drug therapy (three studies), neuromuscular electrical stimulation (NMES; six studies), pharyngeal electrical stimulation (PES; four studies), physical stimulation (three studies), transcranial direct current stimulation (tDCS; two studies), and transcranial magnetic stimulation (TMS; nine studies).Swallowing therapy had no effect on the primary outcome (death or dependency/disability at the end of the trial) based on data from one trial (two data sets) (OR 1.05, 95% CI 0.63 to 1.75; 306 participants; 2 studies; I² = 0%; P = 0.86; moderate-quality evidence). Swallowing therapy had no effect on case fatality at the end of the trial (OR 1.00, 95% CI 0.66 to 1.52; 766 participants; 14 studies; I² = 6%; P = 0.99; moderate-quality evidence). Swallowing therapy probably reduced length of inpatient stay (MD -2.9, 95% CI -5.65 to -0.15; 577 participants; 8 studies; I² = 11%; P = 0.04; moderate-quality evidence). Researchers found no evidence of a subgroup effect based on testing for subgroup differences (P = 0.54). Swallowing therapy may have reduced the proportion of participants with dysphagia at the end of the trial (OR 0.42, 95% CI 0.32 to 0.55; 1487 participants; 23 studies; I² = 0%; P = 0.00001; low-quality evidence). Trial results show no evidence of a subgroup effect based on testing for subgroup differences (P = 0.91). Swallowing therapy may improve swallowing ability (SMD -0.66, 95% CI -1.01 to -0.32; 1173 participants; 26 studies; I² = 86%; P = 0.0002; very low-quality evidence). We found no evidence of a subgroup effect based on testing for subgroup differences (P = 0.09). We noted moderate to substantial heterogeneity between trials for these interventions. Swallowing therapy did not reduce the penetration aspiration score (i.e. it did not reduce radiological aspiration) (SMD -0.37, 95% CI -0.74 to -0.00; 303 participants; 11 studies; I² = 46%; P = 0.05; low-quality evidence). Swallowing therapy may reduce the incidence of chest infection or pneumonia (OR 0.36, 95% CI 0.16 to 0.78; 618 participants; 9 studies; I² = 59%; P = 0.009; very low-quality evidence).

Moderate- and low-quality evidence suggests that swallowing therapy did not have a significant effect on the outcomes of death or dependency/disability, case fatality at the end of the trial, or penetration aspiration score. However, swallowing therapy may have reduced length of hospital stay, dysphagia, and chest infections, and may have improved swallowing ability. However, these results are based on evidence of variable quality, involving a variety of interventions. Further high-quality trials are needed to test whether specific interventions are effective.