Table 1.

Main characteristics of the studies.

Author	Age, Mean (SD), Median	Sample Size	Type of Intervention	Outcome Measures/ Assessment Tools	Results
Nguyen et al. [11]	EG = 7–12, 8.8 (1.59) CG = 7–12, 9.4 (1.93)	N = 49 (9 looses) EG= 20 CG = 20	EG = music on the iPod with headphones CG = headphones with no music	Vital signs. NRS STAIC	EG: pain relief (p < 0.001) during (p < 0.003) and after the interventions EG: reduction of the anxiety (p < 0.001) before and after the LP EG: Changes in HR (p = 0.012) and RR (p = 0.009) before LP an in HR after LP (p = 0.003)
Barry et al. [22]	EG = 6–13, median: 8 CG = 6–13, median: 8	N = 12 (1 loss) EG = 5 CG = 6	EG: creation of a MT CD CG: no MT treatment	Coping strategies Kidcope questionnaire	No significant differences regarding anxiety during RT. No significant differences regarding coping strategies in both groups. Significant differences in relation to social isolation (p = 0.076) which was only present in the CG.
Robb et al. [23]	EG = 9–17 CG = 9–17	N = 8 (1 loss, 1 excluded) EG = 3 CG = 3	EG: 3 active sessions of composition, discussion and songs recording + three passive sessions to avoid fatigue and secondary effects CG: The person participated in one of the following activities of his/her choice: (a) table game, (b) cards game, (c) videogame.	STAIC CDI	All participants in the EG showed lower anxiety levels. The results in the CG were very variable.
Robb et al. [24]	EG = 9–17 CG = 9–17	N = 8 (1 loss, 1 excluded) EG = 3 CG = 3	EG: three active sessions of composition, discussion and songs recording + three passive sessions to avoid fatigue and secondary effects CG: The person participated in one of the following activities of his/her choice: (a) table game, (b) cards game, (c) videogame.	STAIC CDI Likert scale	Four independent readers identifying themes in patient-generated songs, predominant categories for P1’s lyrics included themes related to control or independent coping (19%), hope (14%) and family support (11%); P2′s lyrics included positive physical status (58%), negative physical status (38%), positive mental status (33%), and professional/staff support (19%); P3′s lyrics included family support (75%) and appreciation (38%). Through a Likert scale they evaluated how the condition affected their stay in hospital (5 = very useful, 3 = neutral, 1 = harmful). The results showed that music helped them to use the time for fun (M = 5), and with an average score of 4.5 that “encouraged me to make choices”, “helped me feel good about myself”, “improved my mood”, and “helped me express my thoughts and feelings”.
Robb et al. [25]	EG = 4–7 CG = 4–7 CG = 4–7	N = 83 (1 excluded) EG AME = 27 CG ML 28 CG AB = 28	EG AME: five-part session (greeting, playing and instrument, movement while listening to a song, songs and stories, song to close the session) CG ML: listening to a CD of music CG AB: listening to an audiobook for 10–15 min	Behavioural coding: -Facial expression, -Active participation -Behaviour -Initiation: verbal and gestural	Significant differences on facial expression between the EG and both CG (p < 0.0001). Significant differences between both CG (p < 0.0413). Significant differences in active participation between the EG and both CG (p < 0.0001 both), no significant differences between both CG (p = 0.9527). The CG ML showed the best scores in initiation, followed by EG and CG AB. The difference between the CG ML and the CG AB was significant (p = 0.0019). However, the difference between the EG and the CG ML was not (p = 0.5552).
Cabral-Gallo et al. [29]	EG = 6–18 CG = 6–18	N = 240 (112 patients, 128 carers) EG = 56 CG = 56	EG: music listening CG: no MT treatment	Patients: C-MAS-R Carers: HAS	Mean value of anxiety decreased in the pre-test post-test comparison in the EG (12.71 y 11.95) and the CG (13.89 y 13.21). Both effect sizes were small (0.20 y 0.19). Significant differences in the EG in the physiological anxiety (p = 0.004) and Hyper sensitivity (p = 0.028) dimensions in girls. In the CG there were significant differences in physiological anxiety (0.043). Carers: Statistically significant changes in the EG (p < 0.05) in 12 of the 13 dimensions. Only two dimensions showed significant changes in the CG.
Camprubí [30]	EG = 5–16 CG = 5–16	N = 30 EG = 15 CG = 15	EG: 45 minutes MT session (live music, simple melody expressive songs, dancing, free drawing, musical games with any family member) CG: 45 minutes of a leisure activity adapted to the age of the patient (avoiding music)	Immunoglobulin A in saliva Likert scale	EG: increase of 7 mg/L compared to the pre-test, although the changes were not significant. No significant differences (p > 0.05) in state of mind in the EG (pre-test post-test difference of 0.6) and the CG (increase of 0.4 between the pre-test and the post-test). The difference between the EG and the CG was not significant (p > 0.05).
Uggla et al. [31]	EG = 7.1 (0.5–17) CG = 6.2 (0.2–16)	N = 71 (35 excluded, 7 losses) EG = 14 CG = 15	EG: 45 minutes’ sessions, twice a week during hospitalisation (4–6 weeks). The children were invited to sing, play musical instruments and listen to music. CG: No MT treatment.	PedsQL Performance scale in the game of Lansky	After discharge, the EG showed a significant difference (p = 0.0079) in the physical function domain of the PedsQL as compared with the CG. In addition, the EG had less treatment concerns and anxiety (p = 0.41 y p = 0.17; respectively). The state of mind in the EG improved significantly after music therapy (p = 0.000) in comparison with the CG. Pain decreased in the EG after the intervention but the changes were not statistically significant as compared to the CG.
Uggla et al. [32]	EG = 6 (0.9–16) CG = 6 (0.2–14)	N = 40 (16 declined, 3 losses) EG = 12 CG = 9	EG: 45 minutes’ sessions, twice a week during hospitalisation (4–6 weeks), according to the Nordoff-Robbins Creative Music Therapy and Juliette Alvin’s Free Improvisation Therapy. The child is active and is invited to sing, play various musical instruments and listen to music with the therapist CG: no MT treatment.	Vital signs. Performance scale in the game of Lansky	Significant differences between the evening and morning heart rate of the EG with respect to the GC (p <0.001) were found. Significant difference in saturation, with lower EG scores, with respect to CG (p = 0.06) were observed. However, the night the scores are similar. No significant differences in blood pressure were observed between the groups (p = 0.46)
Giordano et al. [33]	EG = 2–13 CG = 2–13	N = 48 EG = 29 CG = 19	EG: one MT session of 15 to 20 minutes (playing musical instruments, improvisation, singing, musical creation, selection and play of music playlists). CG: entertainment with leisure activities	m-YPAS Likert scale	The EG had significant less anxiety levels after the intervention in comparison to the CG. 66.7% of the interviewed answered“very much“, 30.3% "a lot“ and 3% “sufficiently“ in the question related to the ability to distract the patients.
Saghaeee-Shahriari et al. [34]	EG = adolescents, ages not specified. CG = adolescents, ages not specified.	N = 30 EG = 15 CG = 15	14 sessions of music therapy lasting 90 minutes	ASI General self-efficiency scale	Significant difference in the EG in anxiety sensitivity (p < 0.001) and self-efficiency (p < 0.001) in comparison to the CG.

SD: Standard deviation. EG: Experimental Group. CG: Control Group. LP: lumbar puncture. MT: Music Therapy. CD: Compact disc. P: Participant. NRS: Numeric Rating Scale for pain assessment. HR: Heart rate. RR: Respiratory rate. RT: Radiotherapy. STAIC: State-Trait Anxiety Inventory for Children. CDI: Children depression inventory. P: Participant. AME: Active music engagement. ML: music listening. AB: Audiobook. M: Media. C-MAS-R: Children’s Manifest Anxiety scale revised. HAS: Hamilton Anxiety Scale. PedsQL: Paediatric Quality of Life Inventory. m-YPAS: modified Yale Preoperative Anxiety Scale. CES-DC: Centre for Epidemiological Studies Depression Scale for Children and Adolescents (Chinese version). ASI: Anxiety Sensitivity Index.