Author (Year)	Country	Fatigue
Akbar et al (2016)[@147110]	Canada	Mean (SD) PedsQL™ multidimensional fatigue score (patients with MS ≤18 y vs non-MS self-reported healthy individuals): 30.4 (13.3) vs 22.6 (9.01)
Akbar et al (2016)[@147111]	Canada	Mean (SD) PedsQL™ multidimensional fatigue score (patients with MS <18 y vs healthy controls): 30.8 (14.1) vs 21.9 (7.1)
Akbar et al (2016)[@147112]	Canada	Mean (SD) PedsQL™ multidimensional fatigue score (patients with MS ≤18 y vs age- and sex-matched healthy controls): 30.0 (13.4) vs 23.3 (8.8)
Fuentes et al (2012)[@147091]	Canada	23% patients with RRMS <19 y experienced fatigue
Grover et al (2016)[@147096]	Canada	Median (IQR, % moderate-to-severe) fatigue (Varni Pediatric QOL Inventory Multidimensional Fatigue) (patients with MS vs healthy controls)     General: 7.0 (6.0, 15) vs 7.0 (3.0, 14)     Cognitive: 7.0 (6.0, 19) vs 7.0 (7.0, 11)     Mean (SD, % moderate-to-severe) fatigue     Sleep/rest: 7.8 (4.8, 22) vs 9.3 (3.5, 22)     Total: 21.3 (12.5; 15) vs 23.1 (8.2, 11)
Stephens et al (2019)[@147100]	Canada	Baseline mean (SD) fatigue (PedsQL™) among patients with MS <18 y     Total: 69.5 (16.5)     General: 71.77 (18.9)     Sleep/rest: 64.66 (19.88)     Cognitive: 72.1 (21.0) Fatigue scores over time estimate (SE)     Total: -2.84 (1.03)     General: -3.68 (1.18)     Sleep/rest: -2.62 (1.05)     Cognitive: -1.59 (1.32) T values and P values also included
Till et al (2012)[@147093]	Canada	Experienced chronic fatigue: 43.8% patients with RRMS <18 y vs 0% age- and sex-matched healthy controls
Florea et al (2020)[@147076]	France	43% moderate or severe fatigue on FSS
Storm van’s Gravesande et al (2019)[@147078]	Germany, Austria	Mean (SD) self-reported fatigue scale scores (PedsQL™) (MS children, age-matched healthy controls)     General: 63.15 (25.73), 77.64 (17.83)     Sleep/rest: 55.46 (21.69), 63.15 (19.16)     Cognitive: 65.99 (26.36), 74.52 (20.76)
Storm van’s Gravesande et al (2019)[@147079]	Germany, Austria	Mean (SD) self-reported fatigue scale scores (PedsQL™) (patients with RRMS 12-18 y vs age-matched healthy controls)     General: 63.15 (25.73) vs 77.64 (17.83)     Sleep/rest: 55.46 (21.69) vs 63.15 (19.16)     Cognitive: 65.99 (26.36) vs 74.52 (20.76)     Total: 61.57 (20.78) vs 71.78 (15.58) Classification of total fatigue (%) (patients with MS vs age-matched healthy controls)     None: 59.4 vs 82.8     Mild: 20.8 vs 14.4     Severe: 19.8 vs 2.9 Classification of general, sleep/rest, and cognitive fatigue also included
Kapanci et al (2019)[@147094]	Germany	Mean (SD) fatigue per Modified Fatigue Impact Scale (patients with MS vs age-and sex-matched healthy controls): 32.52 (17.22) vs 23.10 (12.75)
Amato et al (2014)[@147113]	Italy	20% of patients with MS <18 y with fatigue on the FSS
Amato et al (2010)[@147114]	Italy	21% with fatigue on the FSS
De Meo et al (2017)[@147088]	Italy	Mean (SD) FSS among patients with MS 7-18 y: 27.1 (12.1)
Goretti et al (2012)[@147082]	Italy	Mean (SD) of self-reported fatigue (PedsQL™) (patients with MS ≤18 y vs demographically matched healthy controls)     General: 78.5 (18.9) vs 74.2 (14.1)     Sleep: 79.2 (14.3) vs 74.3 (14.5)     Cognitive: 83.0 (15.0) vs 77.5 (17.9)
Pastò et al (2016)[@147085]	Italy	Mean (SD) FSS for patients with RRMS <18 y with cognitive performance that is:     Deteriorating: 3.3 (1.9)     Stable/improving: 2.5 (1.8)
Rocca et al (2016)[@147087]	Italy	Mean (SD) FSS     All patients with RRMS 8-18 y: 27.2 (12.3)     CP patients: 27.6 (11.8)     CI patients: 26 (14.2)
Toussaint-Duyster et al (2018)[@147077]	Netherlands	<1 SD below the mean on PedsQL™ fatigue scores among patients with MS 4-17 y     Total: 36     General: 36     Sleep-rest: 27     Cognitive: 32
Sandvig et al (2015)[@147092]	Norway	61.1% patients with RRMS <16 y reported fatigability
Carroll et al (2016)[@147090]	UK	Five themes emerged from interviews with patients with MS 6-18 y: (1) emotional reactions to fatigue and its impact, (2) the lived experience of fatigue and impact on daily activities, (3) uncontrollability and unpredictability of fatigue (uncontrollability, uncertainty, and lack of knowledge), (4) finding a balance (concern about well-being, future), (5) social support and disclosure
Parrish et al (2013)[@147115]	US, Canada	Mean (SD, % moderate-to-severe elevation) fatigue (n = 24) (Varni Pediatric QOL Inventory Multidimensional Fatigue) (patients with MS 10-18 years vs healthy controls)     Total: 30.04 (18.48, 29.17) vs 20.03 (10.58, 8.62)     General: 9.42 (6.42, 33.33) vs 4.91 (3.68, 3.45)     Cognitive: 10.75 (7.26, 41.67) vs 7.05 (5.12, 20.69)     Sleep/rest: 9.46 (6.37, 37.5) vs 8.05 (4.57, 20.69)
Charvet et al (2016)[@147089]	US	Mean (SD, range) FSS among patients with MS 5-18 y: 30.06 (14.37, 9-53) (n = 46)
Holland et al (2014)[@147116]	US	Mean (SD, range) PedsQL™ Multidimensional Fatigue Scale among patients with MS 7-18 y     Cognitive: 61.80 (23.20, 17-106)     Sleep/rest: 62.12 (22.50, 17-100)     General: 66.88 (19.53, 25-100)     Total: 63.08 (18.06, 25-100)
Zafar et al (2012)[@147117]	US	Mean (SD) total scores (patients with MS 13-18 y vs healthy children in a historical control group)     PedsQL™ Multidimensional Fatigue Scale: 61.53 (19.27) vs 61.06 (17.16)     Adolescent Sleep-Wake Scale: 4.11 (0.89) vs 5.07 (0.77)     Adolescent Sleep Hygiene Scale: 4.48 (0.64) vs 4.35 (0.56)     Modified Epworth Sleepiness Scale: 7.00 (3.36) vs 9.44 (4.14)