Dosages of swallowing exercises in stroke rehabilitation: a systematic review

European Archives of Oto-Rhino-Laryngology (2023) 280:1017–1045 https://doi.org/10.1007/s00405-022-07735-7 REVIEW ARTICLE Dosages of swallowing exercises in stroke rehabilitation: a systematic review Jacinda Choy1,2 · Fereshteh Pourkazemi1 · Caitlin Anderson2 · Hans Bogaardt1,3 Received: 22 August 2022 / Accepted: 29 October 2022 / Published online: 6 December 2022 © The Author(s) 2022 Abstract Purpose To investigate the dosages of swallowing exercises reported in intervention studies on post-stroke dysphagia through systematic review. Methods Five electronic databases were searched from inception until February 2022 with reference tracing of included studies. Studies were included, where adults with post-stroke dysphagia received rehabilitative, behavioural swallowing exercises, pre/post outcomes were reported, and intervention dosage was described in detail, including frequency, intensity, time, and type of exercise. Two reviewers independently screened studies and rated quality using ASHA Levels of Evidence tool. Data was tabulated and narratively described. Results 54 studies were included with a total 1501 participants. Studies included 28 randomised controlled trials, 8 nonrandomised controlled trials, 12 pre/post studies, 3 retrospective case controls and 3 case studies. Results showed inconsistent reporting of intervention dosage, with intensity the least consistently reported dosage component. While swallowing intervention was most commonly provided five times per week for four weeks, there was a wide breadth of type, frequency, intensity and duration of swallowing exercises reported. Dosage under-reporting and variation was particularly observed in “standard care” co-interventions or control groups. Study strengths included following PRISMA guidelines, providing a comprehensive review of swallowing exercise methodology and dosages, and including non-English studies. The limitation was lack of meta-analysis due to the heterogeneity of included studies. Conclusions Dosages of swallowing exercises are inconsistently reported and vary significantly in post-stroke dysphagia studies. Results indicate the need for consistent and comprehensive dosage reporting in dysphagia studies, and for further research into evidence-based principles to optimise swallowing exercise dosages. Systematic review registration number 131294 Keywords Deglutition disorders · Stroke · Exercise therapy · Rehabilitation · Speech-language pathology · Systematic review Introduction Dysphagia is a common and significant symptom following stroke. Dysphagia, or swallowing difficulties, affect a third to over two thirds of patients after stroke [1, 2]. Dysphagia * Jacinda Choy 1 Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia 2 HammondCare Braeside Hospital, Sydney, NSW, Australia 3 School of Allied Health Science and Practice, The University of Adelaide, Adelaide, SA, Australia causes medical complications, including increased hospitalisation, morbidity, and risk of aspiration pneumonia [3]. It is associated with poor psychosocial health outcomes, such as reduced nutrition, hydration and quality of life [4]. Patients with dysphagia have longer lengths of hospital stay and higher healthcare costs [5, 6]. Current management of dysphagia involves compensation and rehabilitation. Compensatory techniques—such as chin tuck or modifying diet and fluid consistencies—enable safe swallowing but do not alter long-term function [7]. Rehabilitative exercises, however, can improve swallowing function and resumption of oral intake or normal food and drink [7]. Rehabilitative exercises can be indirect (motor without swallow) or direct (motor with swallow) [8]. Indirect 13 Vol.:(0123456789) 1018 exercises aim to strengthen muscles involved in swallowing, and include the Shaker head-lift and tongue strengthening exercises [9]. Direct exercises involve the action of swallowing and include the Mendelsohn manoeuvre and effortful swallow [9]. Studies have shown the positive effects of rehabilitative exercises on reducing the severity and symptoms of post-stroke dysphagia [10]. However, there is limited understanding of the optimal way to conduct swallowing exercises, particularly, the optimal dosages of swallowing exercises. Dosage is an important factor which can impact on intervention efficacy and efficiency [11]. According to the American College of Sports Medicine’s (ACSM) FITT framework, dosage consists of Frequency (how often), Intensity (how hard), Time (how long) and Type (what kind) of exercise [12]. Altering or increasing these components of dosage can optimise exercise or intervention outcomes, as seen in sports medicine and stroke rehabilitation [13, 14]. However, there is limited knowledge on what dosages to use for swallowing exercises. Previous scoping and literature reviews have highlighted the paucity of data regarding dosage recommendations in dysphagia intervention [9, 15]. This is reflected in surveys of speech pathologists which indicate variability in the exercises and dosages used to treat dysphagia [16]. The aim of this systematic review was to investigate what dosages of swallowing exercises are reported in studies in post-stroke dysphagia. To our knowledge, only one scoping review has specifically examined the dosages of swallowing exercises [15]. Our review was conducted to systematically update the search with new studies. Given that intervention dosage may vary depending on diagnosis, this review focused on one of the most common causes of acquired dysphagia: stroke [17]. This systematic review aimed to investigate dosage reporting in research and describe current swallowing exercise dosages in intervention studies to guide clinicians when considering dosage prescription. The findings can be used to identify areas for future research in optimising dosage of swallowing exercises to facilitate more cost-effective intervention, increased patient engagement and improved outcomes. Methods This systematic review was conducted according to PRISMA guidelines [18]. Prior to conducting the study, a protocol was registered on PROSPERO (https://www.crd.york.ac.uk/ PROSPERO/, registration number: 131294). Eligibility criteria Studies were included if: (i) they included adult participant/s with dysphagia due to stroke, (ii) they examined 13 European Archives of Oto-Rhino-Laryngology (2023) 280:1017–1045 rehabilitative, behavioural swallowing exercises, (iii) they were a published intervention study, where pre/post outcomes were reported, and (iv) they provided a detailed description of the dosage of the rehabilitative exercise. Only full-text published studies accessible through online databases were included in this review. For the purpose of this review, the ACSM FITT framework was used to specify the minimal elements required in a detailed description of dosage [12]. Dosage description needed to include the frequency (or number) of sessions, i (...truncated)