. 2020 Mar 6;20(1):1–165.

Table A5:

Characteristics of Systematic Reviews Included in the Clinical Evidence Review

Author, Year	Objective(s)	Search Date and Databases Used	Inclusion Criteria					Method of Quality Assessment
Author, Year	Objective(s)	Search Date and Databases Used	Study Design	Population	Intervention(s)	Comparator(s)	Outcome(s)	Method of Quality Assessment
University of Alberta, 2011⁴⁷	To systematically review the evidence on middle ear implants for the treatment of hearing loss	Search date Inception to September 2011 Databases searched MEDLINE Embase	All except editorials, comments and case reports	Adults and children with sensorineural, conductive or mixed hearing loss	Middle ear implants (Vibrant Soundbridge, Esteem, Carina)	No treatment Conventional hearing aids Bone-anchored hearing aids Cochlear implants	Functional gains Speech reception Speech recognition Quality of life Adverse events	Levels of evidence from Oxford Centre for Evidence-Based Medicine¹²⁰
		Cochrane library Web of Science CINAHL PsycINFO CRD
		Unpublished and non-peer-reviewed literature was located through internet searches and included manufacturer and association websites.
		Electronic search was supplemented with a manual search of the reference lists from included articles, recent health technology assessments and systematic reviews.
Appachi et al, 2017⁴⁴	To systematically review the current literature to characterize auditory outcomes of hearing rehabilitation options in children with unilateral hearing loss	Search date Inception to January 2016 Databases searched PubMed Cochrane library CINAHL MEDLINE Embase	All except case reports	Children with unilateral hearing loss	Baha Attract Sophono	No treatment	Functional auditory measures Objective auditory measures Word recognition scores	Newcastle-Ottawa scale¹²¹
		References of identified studies were reviewed to identify additional studies.
Australia Medical Services Advisory Committee, 2010³⁴	To systematically review the evidence on the clinical effectiveness of middle ear implants for patients with mild to severe sensorineural, conductive, or mixed hearing loss	Search date Inception to August 2009 Databases searched PubMed Cochrane library Embase Current Contents	All designs except non-systematic reviews, case reports, letters, editorials, and animal, in vitro, and laboratory studies	Adults with mild to severe sensorineural, conductive, or mixed hearing loss	Middle ear implants (Vibrant Soundbridge, Otologics middle ear transducer, Envoy Esteem, Rion device, Soundtec Direct Drive Hearing System)	Bone-anchored hearing aids Cochlear implants	Functional gains Speech perception Quality of life Adverse events	Dimensions of evidence from the National Health and Medical Research Council^a
Bezdjian et al, 2017⁴⁸	To systematically review published papers presenting Sophono implanted patients to delineate the device's functional improvement and perioperative outcomes	Search date 1975 to August 2016 Databases searched PubMed Embase Cross-reference checking was conducted to retrieve studies not identified in the initial search strategy.	All designs except case reports, letters, commentaries, literature reviews, abstracts	Adults and children with single-sided deafness or conductive or mixed hearing loss	Sophono	No treatment	Hearing thresholds Adverse events	Critical appraisal checklist^b
Colquitt et al, 2011⁴⁹	To assess the clinical effectiveness of bone-anchored hearing aids for people who are bilaterally deaf	Search date Inception to November 2009 Databases searched Web of science CENTRAL Cochrane library DARE Embase CRD Health Management Information Consortium MEDLINE Web of knowledge Reference lists of retrieved articles were examined for additional studies. Expert advisory group and manufacturers were contacted for additional references.	RCTs Controlled clinical trials Prospective cohort studies and case series Cross-sectional studies	Adults and children with bilateral hearing loss	Bone-anchored hearing aids	No treatment Conventional hearing aids Bone-conduction hearing aids	Audiometry Speech audiometry Self-reported measures	Quality assessment criteria by Thomas and colleagues¹²²
Danhauer et al, 2010⁵⁰	To determine if the evidence supports the recommendation of bone-anchored hearing aids over unaided conditions in persons with conductive hearing loss	Search date Inception to 2010 Databases searched PubMed ComDisDome CINAHL CDSR	Systematic reviews RCTs Nonrandomized interventional studies	Children with congenital unilateral aural atresia	Bone-anchored hearing aids	No treatment	Audibility Speech perception Sound localization Quality of life	Quality assessment criteria by Chisolm and colleagues¹²³
		Reference lists of retrieved articles were hand-searched for additional relevant studies.
Ernst et al, 2016⁵¹	To systematically review the safety and effectiveness of the Vibrant Soundbridge in treating conductive and mixed hearing loss	Search date January 2006 to April 2014 Databases searched PubMed MEDLINE Embase CRD Cochrane library	Did not specify	Adults and children with conductive or mixed hearing loss	Middle ear implants (Vibrant Soundbridge)	No treatment Bone-conduction hearing implantable devices Middle ear surgery with conventional hearing aids	Hearing thresholds Functional gains Speech recognition Subjective outcomes Adverse events	Levels of evidence from Oxford Centre for Evidence-Based Medicine¹²⁰ Checklist from the Evidence Analysis Library, Academy of Nutrition and Dietetics^c
		The list of study titles was supplemented with potentially relevant publications already known by the research team.
		The bibliographic references of reviews were searched to locate additional relevant materials.
Johnson et al, 2006⁵²	To systematically review the nonacoustic benefits for adult patients receiving bone-anchored hearing aids relative to other forms of amplification	Search date Did not specify Databases searched PubMed ComDisDome	Randomized controlled trials Nonrandomized interventional studies Cohort studies	Adults and children with conductive or mixed hearing loss	Bone-anchored hearing aids	No treatment	Quality of life	Quality assessment criteria by Taylor et al¹²⁴
Kim et al, 2017⁴⁵	To analyze the present capabilities of bone-anchored hearing aids in the context of single-sided deafness and to evaluate their efficacy in improving speech recognition in noisy condition, sound localization, and subjective outcomes	Search date Inception to August 2015 Databases searched Cochrane library MEDLINE Embase Relevant conference proceedings were hand-searched.	RCT Non-RCT Cohort studies Before-and-after studies Case–control studies	Adults and children with single-sided deafness or unilateral hearing loss	Bone-anchored hearing aids	No treatment	Speech discrimination in noise Sound localization Subjective benefits Adverse events	Critical appraisal checklists of the Scottish Intercollegiate Guidelines Network¹²⁵
Kiringoda and Lustig, 2013⁵⁶	To summarize available peer-reviewed literature to describe the range and rate of complications related to osseointegrated hearing aids in adult and pediatric patients	Search date Between 2000 and 2011 Databases searched PubMed Embase	All except case reports, general reviews, commentaries, and studies that did not include patient outcomes, that reported outcomes associated with nonstandard implantation, or were of poor study or reporting quality	Adults and children who were implanted with bone-anchored hearing aids	Bone-anchored hearing aids	No treatment	Complications	Sackett levels of evidence¹²⁶
Kitterick et al, 2016⁴¹	To assess the nature and quality of the evidence for the use of hearing instruments in adults with unilateral severe to profound sensorineural hearing loss	Search date Inception to February 2015 Databases searched PubMed Cochrane library CINAHL DARE MEDLINE Embase Other databases were searched using their public-facing websites.	All except published abstracts, articles published in non-peer-reviewed publications and unpublished studies	Adults with unilateral severe to profound sensorineural hearing loss	Cochlear implants Bone-conduction devices	No treatment Contralateral routing of signals	Speech perception Sound localization Quality of life Adverse events	Downs and Black risk of bias checklist¹²⁷
		Reference lists of articles that met the inclusion criteria were searched for potentially eligible articles.
Klein et al, 2012⁵³	To examine the safety and effectiveness of fully implantable middle ear devices in the treatment of hearing loss	Search date Inception to September 2011 Databases searched MEDLINE Embase Cochrane library Web of science CINAHL PsycINFO CRD	All except editorials and comments	Adults and children with sensorineural, conductive or mixed hearing loss	Middle ear implants (Carina, Esteem)	No treatment Conventional hearing aids	Functional gains Speech reception Speech recognition Quality of life Averse events	Levels of evidence from Oxford Centre for Evidence-Based Medicine¹²⁰
		Unpublished and non-peer-reviewed literature was located through Internet searches using Google and scans of websites of manufacturers and professional associations.
		The electronic search was supplemented by a manual search of the references lists from included studies.
Mandavia et al, 2017⁴²	To provide stakeholders with a transparent and pragmatic assessment of the quality of the body of evidence available to inform current UK national policy on bone-conducting hearing devices	Search date Inception to September 2016 Databases searched MEDLINE Embase	All except conference proceedings and letters	Adults and children with single-sided deafness or conductive or mixed hearing loss	Bone-conduction devices	Did not specify	Did not specify	GRADE³⁶
Medical Advisory Secretariat, 2002⁵⁴	To assess the effectiveness and cost-effectiveness of bone-anchored hearing aid in improving the hearing of people with conductive or mixed hearing loss	Search date January 1990 to May 2002 Databases searched Cochrane library MEDLINE Embase CCOHTA reports INAHTA AHRQ	Systematic reviews RCTs Nonrandomized controlled studies Case series	Adults and children with conductive or mixed hearing loss	Bone-anchored hearing aids	No treatment Conventional hearing aids Bone-conduction hearing aids	Hearing thresholds Speech recognition in quiet and noise Patient satisfaction Adverse events	Goodman's hierarchy of levels of evidence¹²⁸
		Websites of Health Canada, Food and Drug Administration, and manufacturers were searched.
Peters et al, 2015⁴⁶	To systematically review the literature on the clinical outcomes of bone-conduction devices and contralateral routing of sound systems for patients with single-sided deafness	Search date Inception to April 2014 Databases searched PubMed Embase Cochrane library CINAHL	All except narrative reviews, case reports, and symposium programs	Adults with single-sided deafness	Bone-conduction devices Contralateral routing of signals	No treatment	Speech perception in noise Sound localization Subjective benefits	Critical appraisal checklist^d
		Cross-reference checking and related article search were performed.
Peters et al, 2016³⁸	To systematically review the literature on cochlear implantation for children with unilateral hearing loss	Search date Inception to June 2015 Databases searched PubMed Cochrane library CINAHL Embase	All except abstracts, non-peer-reviewed articles	Children with unilateral or asymmetrical hearing loss	Cochlear implants	No treatment	Speech perception Sound localization Quality of life Speech and language development	Critical appraisal checklist^d
Sprinzl and Wolf-Magele, 2016⁴³	To assess the safety and effectiveness of the Bonebridge for individuals with conductive or mixed hearing loss and single-sided deafness	Search date Inception to June 2014 Databases searched PubMed Cochrane library MEDLINE Embase	All	Adults and children with conductive or mixed hearing loss and single-sided deafness	Bonebridge	No treatment Conventional hearing aids	Functional gains Speech perception Subjective benefits Patient satisfaction Adverse events	National Health and Medical Research Council levels and grades of evidence^e
		Literature was supplemented by presentations from relevant conferences.
van Zon et al, 2015³⁹	To systematically review the literature to evaluate clinical outcomes of cochlear implantation for patients with single-sided deafness or asymmetrical hearing loss	Search date Inception to December 2013 Databases searched PubMed Cochrane library CINAHL Embase	All except narrative reviews, case reports	Adults with single-sided deafness or asymmetrical hearing loss	Cochlear implants	No treatment	Speech perception Sound localization Quality of life Tinnitus	Critical appraisal checklist^d
		Cross-reference and related article search was performed.
Verhaert et al, 2013⁵⁵	To systematically review the literature on clinical outcomes and safety of acoustic hearing implants in adults with mixed hearing loss	Search date Inception to March 2013 Databases searched MEDLINE Cochrane library Embase	All except case reports, narrative reviews, editorials	Adults with mixed hearing loss	Cochlear implants Bone-anchored hearing aids Middle ear implants	No treatment Conventional hearing aids	Functional gains Speech perception Self-reported outcomes Adverse events	Levels of evidence from Oxford Centre for Evidence-based Medicine¹²⁰ Quality assessment criteria^f
Vlastarako et al, 2014⁴⁰	To critically review the current evidence on the efficacy of cochlear implantation as a treatment modality for single-sided deafness and/or unilateral tinnitus	Search date Inception to May 2013 Databases searched MEDLINE Other available database sources	Did not specify	Adults and children with postlingual single-sided deafness and/or unilateral tinnitus	Cochlear implants	No treatment	Speech perception Sound localization Tinnitus Quality of life	Evidence-based guidelines for the categorization of medical studies¹²⁹
		Reference lists from the retrieved articles were manually search.

Abbreviations: AHRQ, Agency for Healthcare Research and Quality; CCOHTA, Canadian Coordinating Office for Health Technology Assessment; CDR, Cochrane Database of Systematic Reviews; CENTRAL, Cochrane Central Register of Controlled Trials; CINAHL, Cumulative Index to Nursing and Allied Health Literature; CRD, Centre for Reviews and Dissemination; DARE, Database of Abstracts and Reviews of Effects; GRADE, Grading of Recommendations Assessment, Development and Evaluation; INAHTA, International Network of Agencies for Health Technology Assessment; RCT, randomized controlled trial.

Methodological quality was assessed in 3 domains: strength of the evidence, size of the effect, and relevance of the evidence.

Directness of evidence was assessed using 6 criteria: indication for surgery (clearly reported diagnosis), demographic data (including age at surgery, gender, implant laterality), description of surgical technique, complications, audiological improvement (in dB), and follow-up time (in months). Risk of bias was assessed using 5 criteria: loss to follow-up, standardization of treatment, standardization of complication (according to the Holgers classification), missing data and standardization of audiological tests (audiological performance assessed according to a protocol and by an individual other than the surgeon).

Quality assessment criteria included conflict of interest, power analysis, confounding factors considered, appropriate statistical analysis, sufficient follow-up, outcomes clearly defined, extra/unplanned treatment described, interventions specified, withdrawals/excluded or lost to follow-up, sample characteristics described, inclusion/exclusion criteria defined, research question clearly specified, prospective study.

Risk of bias was assessed by blinding, randomization, allocation concealment, standardization of interventions, standardization of outcome measures, and completeness of outcome data for primary outcome. Directness of evidence assessed outcome measurements with respect to patient population, treatment intervention, and outcome measurements.

Quality of evidence was assessed by evidence base (number of studies, level of evidence and risk of bias), consistency, clinical impact, generalizability, and applicability.

Quality of studies was assessed based on ethical approval, prospective study, eligibility criteria specified, power calculation made, appropriate controls and outcome measures used, confounding factors reported and controlled for, appropriate analysis made, and any missing data accounted for.