Table 1 Summary of included articles

Ahlberg

2011 [14]

Nonselective, longitudinal, prospective cohort study

Alternate RT center

Experimental n=190

Control n=184

Yes

Negative

Equivalent

Ajmani

2018 [38]

Retrospective cohort study

Patients seen prior to initiation of swallowing rehabilitation program

Experimental n=119

Control n=135

Yes

Positive

Baudelet

2020 [32]

Study protocol for a randomized controlled trial

Service delivery method

Proposed 1:1:1 recruitment

App supported n=50

Therapist supported n=50

Patient directed n=50

Yes

N/A

Carmignani

2018 [30]

Part 1: retrospective

Part 2: prospective two-arm case–control analysis

Usual care

Experimental n=6

Control n=6

Yes

Positive

Carnaby-Mann

2012 [15]

Randomized Control Trial

Sham exercises

Usual care

Experimental n=20

Sham n=18

Usual Care n=20

Yes

Positive

Equivalent

Carroll

2008 [35]

Retrospective case control

Post cancer treatment exercise only

Experimental n=9

Control n=9

No

Positive

Equivalent

Cnossen

2014 [22]

Feasibility study

Mode of program delivery

Leaflet n=11

Booklet + DVD n=11

Online n=11

No

N/A

Cnossen

2017 [24]

Prospective clinical cohort study

None

n=50

Yes

N/A

Duarte

2013 [36]

Case series with chart review

Noncompliant group

Experimental n=57

Control n=28

Yes

Positive

Equivalent

Govender

2020 [33]

Two-arm parallel group non-blinded randomized feasibility trial

Usual care

Experimental n=16

Control n=16

Yes

N/A

Guillen-Sola

2019 [26]

Protocol for a single-blind randomized clinical trial

Late intervention (immediately after CRT completion)

Proposed 1:1 recruitment

Yes

N/A

Hajdu

2019 [27]

Randomized Control Trial

None (reports on adherence within the experimental group of a randomized control trial)

n=45

N/A

N/A

Hutcheson

2013 [42]

Retrospective observational study

Non-adherent group

Experimental n=286

Control n=211

No

Positive

Kotz

2012 [16]

Randomized controlled trial

Usual care

Experimental n=13

Control n=13

Yes

Positive

Kraaijenga

2015 [23]

Randomized controlled trial

Repeated Measures

Baseline n=55

2 year n=29

6 year n=22

Yes

Positive

Kulbersh

2006 [17]

Prospective cohort study and cross-sectional QOL analysis

Post treatment exercise (first visit after the initiation of their treatment).

Experimental n=25

Control n=12

No

Positive

Equivalent

Mashhour

2018 [28]

Comparative study

Not defined

Experimental n=30 Control n=30

Yes

Positive

Equivalent

Messing

2017 [25]

Randomized controlled trial

Usual care

Experimental n=30

Control n=30

Yes

Positive

Equivalent

Mortensen

2015 [18]

Randomized controlled trial

Usual care

Experimental n=22

Control n=22

Yes

Equivalent with positive trends

Ohba

2016 [37]

Retrospective case-control design

Exercise provided when dysphagia developed

Experimental n=21

Control n=30

Yes

Positive

Peng

2015 [40]

Retrospective case series

Prior to initiation of Swallowing Preservation Protocol (SPP) and those not enrolled once SPP was initiated

Experimental n=41

Control n=66

Yes

Positive

Retel

2011 [41]

Retrospective cost-effectiveness analysis

Usual Care

Experimental n=37

Control n=53

No

Positive

Shinn

2013 [39]

Retrospective

None

n=109

No

N/A

Starmer

2018 [34]

Feasibility trial

None

n=36

No

N/A

Tang

2011 [19]

Randomized controlled trial

Usual Care

Experimental n=22

Control n=21

Yes

Positive

van der Molen

2011 [20]

Randomized controlled trial

Usual Care

Experimental n=27

Control n=22

Yes

Positive

Virani

2015 [21]

Prospective alternate assignment and characteristic matching

Repetitive swallows

Experimental n=26

Control n=24

Yes

Positive

Equivalent

Wall

2020 [31]

Three-arm prospective stratified parallel group study with 1:1:1 random allocation.

Repeated Measures Service delivery mode

Technology n=25

Clinician directed n=25

Patient directed n=27

Yes

N/A

Wells

2016 [29]

Feasibility study using quantitative and qualitative research methods within a quasi-experimental design

Usual Care

Proposed:

Experimental n=40

Control n=30

Yes

N/A