Table 2.

Summary chart of the studies included in the systematic review.

Author and title	Study's objective	Methods/participants	CI information	Questionnaires utilized/aspects assessed	Conclusion
Anmyr L, Olsson M, Larson K, Freijd A. Children with hearing impairment - Living with cochlear implants or hearing aids. International Journal of Pediatric Otorhinolaryngology. 2011;75(6):844-9.	Enhance knowledge on the daily activities of children with CI and ISAD, and their knowledge concerning their hearing and the behavior of others in relation to them.	-Cross-sectional study -Level of evidence ASHA 4 -74 Children (36 with CI and 38 with ISAD) -Participants’ ages: 6 to 15 years -Control group: Yes -The children answered the questionnaires.	Children who received the CI at 3 years and 10 months; Children who received the ISAD at 5 years and 3 months. No information regarding the CI/ISAD use duration.	Questionnaire based on the CIF-CY. Encompassing the following aspects: 1 -Device use and associated factors 2 -Hearing in different day-to-day situations 3 -Children's perception regarding their hearing and the behaviors of others 4 -Choice of type of communication.	Body Functions: Neck and shoulder pains were significantly more common among children with the ISAD than their CI counterparts; Activities: The children with ISAD use their devices less frequently than the children with CI. More children with CI use sign language than children with ISAD; Participation: More children with ISAD had auditory problems than children with CI while participating in sports and outdoor activities. Children from both groups reported situations in which they would like to hear better, in the classroom for instance, during talks with their families and when they needed to hear at distances; Personal and environmental factors: Many children with CI and ISAD did not find their hearing a problem.
Warner-Czyz AD, Loy B, Tobey EA, Nakonezny P, Roland PS. Health-related quality of life in children and adolescents who use cochlear implants. International Journal of Pediatric Otorhinolaryngology, 2011;75(1):95-105.	Checked the impact of chronological age in the self-assessment results of children with CI on the Health-Related Quality of Life questionnaire (HRQL).	-Cross-sectional study -ASHA 4 level of evidence -138 children using CI -Age of the participants: 4 to 16 years -Control group: No -Children who answered the questionnaire.	-Received the CI at a mean age of 3.7 years -Mean time using the CI: 5 years.	Using both questionnaires: 1 -KINDLR (Generic HRQL assessment). Covers the following: Physical well-being; emotional well-being; Self-esteem; Family; Friends; School. 2 -One specific for CI, created by the authors. Covering the following aspects: Satisfaction with the CI; Physical well-being; friends; school; self-esteem; social aspects.	Younger children (4-7 years) and using the CI for less time had a more positive HRQL assessment than older children in the KINDLR questionnaire. In the CI-specific questionnaire, the younger group (4-7 years) had a more positive score than the older children. Chronological age differences showed in the CI module in the items associated with friends, school and self-esteem. The issue about the difficulty in hearing the teacher had the opposite effect, in which the younger children reported the worst score. The group of children between 12-16 years was more regular and reliable in their answers.
Sach TH, Barton GR. Interpreting parental proxy reports of (health-related) quality of life for children with unilateral cochlear implants. International Journal of Pediatric Otorhinolaryngology. 2007;71(3): 435-45.	To study which factors are associated with the EuroQol EQ-5D score in children with CI, and to explore the concepts of the parents on health-related quality of life (HRQL) and Quality of Life (QL).	-Cross-sectional study -ASHA 4 evidence level -216 parents from 222 children with CI (6 parents with two children users of CI) -Mean age of the children: 9.26 years -Control group: No -Parents who answered the questionnaires.	-Age they received the CI: 108 children: < 4 years 114 children: > 4 years -CI time of use: 110 used < 4 years 112 with > 4 years of use.	EQ-5D - Encompasses the following aspects: Mobility; self-care; usual activities; pain; anxiety and depression. Assessment of the health-related quality of life and quality of life, by means of the analogue-visual scale.	They found that the EQ-5D validity construct is variable, although it was capable of discriminating among the children with certain levels of auditory performance, not capable of discriminating among the children who differ in other ways. Moreover, since most of the parents reported that their kid had the same score before and after the implant on a VAS, they inferred that most of the parents rejected the notion that hearing loss was a question of HRQL.
Huber M. Health-related quality of life of Austrian children and adolescents with cochlear implants. International Journal of Pediatric Otorhinolaryngology. 2005;69(8):1089-101.	Aimed at studying the HRQL of school-aged children.	-Cross-sectional study -ASHA 4 level of evidence 4 -29 children with CI and their parents: 18 children: -Age between 8-12 years; 11 adolescents: ages between 13-16 years -Control group: No -Children and parents answered the questionnaires.	-Mean age in which they received the CI: children: 4.3 years; Adolescents: 7.3 years -Mean time using the CI: children: 6.3 years; Adolescents: 6.9 years.	KINDLR (Assessment of the generic HRQL). Encompasses the following aspects: physical well-being, emotional well-being; self-esteem; family; friends; school.	In comparison with the normal-hearing children, CI children (ages between 8 and 12 years) had below-the-average quality of life, often times perceived by their parents. On the other hand, the adolescents (ages between 13 and 16) reported a normal quality of life.
Schorr EA, Roth FP, Fox NA. Quality of Life for Children With Cochlear Implants: Perceived Benefits and Problems and the Perception of Single Words and Emotional Sounds. Journal of Speech, Language, and Hearing Research. 2009;52(1):141-52.	To study the subjective perceptions of the children regarding their quality of life with the CI, measured by the report of benefits and problems associated with the device and check to see if the CI at an early age could predict their QL perception with their CI.	-Cross-sectional study -ASHA 4 level of evidence -37 children: 16 boys and 21 girls -Age at the study: 5-14 years (mean of 9 years) -Control group: No -Children who answered the questionnaires.	-Mean age at which they received their CI was 3.2 years -Mean time of use: 5.9 years.	QL questionnaire created for CI children, approaching the following aspects: Frustration; Use of the telephone; Speech understanding; Make new friends; Hear environmental sounds; Academic performance.	The children reported considerable benefits with the CI regarding improvements in their hearing and communication skills and in fields such as social interaction and academic performance. The child has few problems with the CI, especially the conflict with the parents when they do not want to use their CI. Although age at the implant did not predict benefits or problems associated with the CI, the age at which the amplification started predicts the QL score. This implies that early confirmation of the HL and the ISAD use contributes to a positive result in HL.
Loy B, Warner-Czyz AD, Tong L, Tobey EA, Roland PS. The children speak: An examination of the quality of life of pediatric cochlear implant users. Otolaryngology-Head and Neck Surgery. 2010;142(2):247-53.	Checks whether children with CI show, based on their own answers, psychosocial issues similar to those of the hearing counterparts, and if their parents are reliable responders regarding the HRQL of their children.	-Cross-sectional study -ASHA 4 level of evidence -84 children -50 children between 8-11 years of age (mean of 9.1 years); and 33 children with 12-16 years of age (mean of 13.7 years) -Control group: Yes (normal hearing children) -Children and parents who answered the questionnaires.	-CI group mean age 8-11 years: 3.37 years, and use duration of 5.71 years -12-16 years CI group mean age: 5.83 years and use duration of 7.87 years.	KINDLR (Generic HRQL assessment). Covers the aspects: Physical well-being; Emotional well-being; Self-esteem; Family; Friends; School.	In general the QL assessment of the children and adolescents did not differ between the children with CI and normal-hearing children. However, CI children from the 8-11 years group had a more positive score with their families than their normal-hearing counterparts. The 8-11 year-old children had a more positive Q score than the 12-16-year-old group. CI children and parents agreed in the general QL, but the parents of children with CI of 12-16 years overestimated the success of the adolescents at school vis-à-vis the child's self-assessment. The general QL showed a significantly inverse association between the age at implant and a significantly positive correlation with CI use duration in the 12-16 years of age group.
Warner-Czyz AD et al. Parent versus child assessment of quality of life in children using cochlear implants. International Journal of Pediatric Otorhinolaryngology. 2009;73(10):1423-9.	To explore the multidimensional HRQL aspects in 50 CI users between 4 and 7 years of age, by their self-assessment and parents’ assessment.	-High-quality non-randomized controlled trials -ASHA 2b level of evidence -50 children with CI and their parents. -Mean age at the study: 5 years -Control group: yes (normal hearing children) -Parents and children answered the questionnaires.	-Mean age at which they received the CI: 2.52 years -Mean time of CI use: 3.27 years.	KINDLR (Generic HRQL assessment). Covers the following aspects: Physical well-being; Emotional well-being; Self-esteem; Family; Friends; School.	The children had a significantly more positive QL score than their parents. The total QL had an inversely significant association with the duration of CI use and their chronological age during their assessment. There was no significant correlation between total QL and the age at HL identification or age at surgery. The QL assessment did not differ between children with CI and those with normal hearing.
Huttunen K et al. Parents’ views on the quality of life of their children 2-3 years after cochlear implantation. International Journal of Pediatric Otorhinolaryngology. 2009;73(12):1786-94.	The present study aims at exploring the quality of life of Finish children and families after the CI surgery using a validated questionnaire.	-Cross-sectional study -ASHA 4 level of evidence -36 children with CI -Mean age at the study: 5 years -Control group: No -Parents who answered the questionnaires.	-Mean age at CI surgery: 3 years and 5 months -44% used the CI for 2 years and 56% for 3 years.	“Children with cochlear implants: parental perspectives”. Encompasses the following aspects: Communication; General functionality; Self-sufficiency; Well-being and happiness; Social relations; Education.	The CI improved the QL of the children and parents. The parents reported being very much pleased with the quality of life of their children after 2 to 3 years of CI use. The parents’ expectations were better in the following aspects: social relations, communication, general functionality with the CI and child's self-confidence. Speech-intelligibility results were associated with a better development of communication and school performance.
Incesulu A, Vural M, Erkam U. Children With Cochlear Implants: Parental Perspective. Otology & Neurotology. 2003;24(4):605-11.	To assess parents expectations and the progress of child according to the parents.	-Cross-sectional study -ASHA 4 level of evidence -28 children: 19 boys and 9 girls -Age between 2 and 13 years (CI group mean of 5.07 years) -Control group: No -The parents answered the questionnaires.	-Mean age at which they received the CI: no information -CI time of use between 12 and 30 months (mean 19.5 months).	“Children with cochlear implants: parental perspectives”. Encompasses the following aspects: Communication; General functionality; Self-sufficiency; Well-being and happiness; Social relations; Education.	For the parents, to decide on the cochlear implant surgery is one of the most stressful steps in the process. Although speech and language development had been their main concern, the parents reported noteworthy improvements in their child's communication skills, social relations, and self-confidence. All the families were concerned with device failure.