Effectiveness of orthotic treatment for adolescent idiopathic scoliosis: a scoping review protocol of systematic reviews

Abstract

Introduction

Spinal orthosis is a common conservative treatment for adolescent idiopathic scoliosis (AIS), and a large body of compelling evidence from systemic review studies strongly supports the use of spinal orthosis treatment in patients with this condition. To further improve our understanding of the available data, the aim of this study is to develop and propose a protocol for a scoping review of systematic reviews of studies that investigated the effectiveness of orthotic treatment in patients with AIS. Systematic synthesis and understanding of the data will improve the efficacy of spinal orthosis treatment in this patient population.

Method and analysis

Using the scoping review methodological framework proposed by Arksey and O’Malley in 2005, we developed and herewith propose a scoping review protocol to evaluate systematic reviews of studies that investigated the effectiveness of orthotic treatment in AIS. Our proposed scoping review proposal is briefly described, as follows. A search of seven online databases will be conducted to identify systematic reviews published in English language from 1 January 2000 to 31 December 2023, and grey literature and reference lists of included articles will also be searched. A two-stage screening process consisting of a title and abstract screening and a full-text review will be used to determine articles’ eligibility. All eligible articles will be extracted, charted and evaluated using Assessing the MeaSurement Tool to Assess systematic Reviews Version 2 (AMSTAR-2) critical appraisal tool. The charted data will be quantitatively analysed and summarised, and qualitatively analysed using narrative synthesis.

Ethics and dissemination

No primary data will be collected; therefore, ethics approval is not required. Findings will be disseminated through national and international conferences and publication in a peer-reviewed journal.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This scoping review study protocol was rigorously designed following the published methodological scoping review guideline and framework.

• A comprehensive search strategy was developed in consultation with an experienced librarian to achieve a rigorous, comprehensive and sensitive search of relevant literature.

• The methodological quality of included systematic reviews will be evaluated using A MeaSurement Tool to Assess systematic Reviews Version 2 (AMSTAR-2) critical appraisal tool.

• A potentially important limitation of this study is the possibility of missing relevant articles not published in English.

Introduction

Scoliosis is an abnormal deformity of the spine that is defined as a Cobb angle of lateral curvature of greater than 10° with vertebral rotation.^1–10 There are three types of scoliosis, including congenital, idiopathic and neuromuscular scoliosis, and approximately 80% of patients have idiopathic disease.1 3 6 9 The prevalence of idiopathic scoliosis varies according to age group. The age range of 11–18 years (adolescence) is the most frequently observed, and adolescent idiopathic scoliosis (AIS) accounts for approximately 80%–85% of all idiopathic scoliosis cases.^{7 9} This disease affects approximately 2%–4% of adolescents with female predominance, and it can lead to significant physical and psychosocial burden if left untreated.1 3 4 6 9 11 It is important to note that these percentages are approximate and that they can vary according to study population and classification criteria.⁴

Various treatment approaches have been developed to manage AIS, ranging from observation to bracing, exercises and surgery according to the severity of the spinal deformity.4 6 7 9 12 Approximately 10% of diagnosed AIS cases are indicated for conservative treatment to halt or slow curve progression, to prevent or treat respiratory dysfunction and spinal pain syndromes, and to influence postural correction to improve appearance. Approximately 0.1%–0.3% of patients require surgical treatment for spinal deformity correction.^{7 9 12}

Among the available conservative treatments, orthotic treatment is widely used to stop or reduce the progression of spinal curvature and to prevent or minimise the need for surgical intervention.^{4 9 13} The effectiveness of and the factors associated with orthotic management of AIS have been extensively studied in order to optimise treatment strategies.^{14 15} Moreover, many systematic reviews of studies in the orthotic treatment for AIS have been conducted. However, most of those systematic reviews focused on different orthotic designs and the effectiveness of orthotic treatment,^16–24 and only one systematic review evaluated the effectiveness of different bracing concepts in AIS.²⁵ Recent comprehensive systematic reviews also examined compliance of orthotic treatment,²⁶ predictive factors of orthotic treatment outcomes^27–29 and comparison between orthotic treatments and other treatments, including physiotherapy, exercise intervention and surgical treatment.^30–36

Our initial and informal review of systematic reviews of studies that have investigated orthotic treatment in AIS revealed some overlap across studies; however, the standalone studies and the systematic reviews of those studies may not yield overarching essential insights into the use, mechanisms, effectiveness and long-term outcomes of orthotic treatment in AIS. Moreover, they may not yield new and important information. A scoping review of previously conducted systematic reviews is, therefore, needed to add a new level of data synthesis to more effectively mine as much information about orthotic treatment in AIS from existing data as is reasonably possible using the currently available data management and analysis tools. Accordingly, the aim of this study is to develop and propose a protocol for a scoping review of systematic reviews of studies that investigated the effectiveness of orthotic treatment in patients with AIS. Specifically, our proposed scoping review protocol sets forth to (1) map the range of systematic reviews conducted to evaluate the orthotic treatments used to treat AIS; (2) to identify associations between orthotic treatments and patient/treatment outcomes for the purpose of refining AIS management; and (3) to identify gaps in the research specific to orthotic treatment in AIS that warrant future study.

The findings of this scoping review will contribute to bridging the gap between research and practice and guiding healthcare professionals in their clinical decision-making regarding orthotic treatment for AIS. Additionally, it will identify areas requiring further research and inform future research directions, ultimately leading to improve patient outcomes and enhance quality of care for individuals with AIS. Overall, the importance of this study lies in its potential to provide a synthesised overview of the current evidence on orthotic treatment effectiveness, helping shape clinical practices and advance knowledge in the field of AIS management.

Methods and analysis

Protocol

A scoping review designed to comprehensively evaluate the existing literature and to identify the areas in which research might be necessary in the future was developed using a predefined protocol format following the methodological framework of Arksey and O'Malley,³⁷ and with recommendations by Levac et al.³⁸ The scoping review protocol comprises both a framework for the study procedures and a description of the study process. This scoping review framework consists of six stages, including (1) identifying the research question, (2) identifying relevant studies, (3) selecting studies, (4) charting the data, (5) collating, summarising and reporting the results and (6) consultation. The scoping review process is an iterative review, particularly during the study selection phase. The conduct and reporting of the scoping review will be consistent with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist.³⁹

Stage 1: identifying the research question

The specific questions guiding this scoping review are:

1. What is the range of systematic reviews conducted to evaluate orthotic treatments used to treat AIS?

2. What are the associations between orthotic treatments and patient/treatment outcomes for the purpose of improving AIS management?

3. What are the gaps in the research specific to orthotic treatments in AIS that warrant future study?

Stage 2: identifying relevant studies

The proposed search process will comprise the following two phases: (1) electronic bibliographic databases searches and (2) grey literature search.

Electronic bibliographic databases

The comprehensive and systematic search strategy, designed to maximise comprehensiveness and sensitivity in the initial search followed by increased specificity in the later screening stage,⁴⁰ was developed and tested by the authors (WS, KP and SS) using an iterative process in consultation with an expert medical librarian.

The proposed search strategy is to search the following online databases: MEDLINE (Ovid), MEDLINE in process (Ovid), EMBASE (Ovid), PsycINFO (Ovid), Scopus, CINAHL (EbscoHost) and Cochrane Library (Wiley). All sources will be searched from 1 January 2000 to 31 December 2023, and only studies published in English language will be eligible for inclusion. The English-only studies was influenced by resource restrictions (eg, lack of funds for language translation). The year 2000 was selected based on the finding of a preliminary search that showed that systematic reviews related to this topic were almost exclusively published from this year onwards. The proposed search keywords will include ‘adolescent idiopathic scoliosis’, ‘orthotic device/orthosis’, ‘brace’ and ‘systematic review’. An example of the proposed search strategy of the MEDLINE database is shown in table 1. The proposed search strategy to be used in all databases is presented in online supplemental document 1. In addition, hand searching of the reference lists of the included publications will be performed consecutively throughout the search process.

Table 1.

A search query of the MEDLINE database that was performed on 15 June 2023

Query	Records retrieved
(((‘adolescen*’[All Fields] OR ‘adolescen*’[MeSH Terms]) AND ((‘idiopathic*’[All Fields] OR ‘idiopathic*’[MeSH Terms]) AND (‘scolios*’[MeSH Terms] OR ‘scolios*’[All Fields])) AND (‘brace*’[All Fields] OR ‘brace*’[MeSH Terms] OR (‘orthotic devices’[MeSH Terms] OR ‘orthotic devices’[All Fields] OR ‘orthos*’[All Fields]))) AND (systematicreview[Filter])	34

MeSH, medical subject headings.

Grey literature

Subsequently to the search in electronic bibliographic databases, OpenGrey and Google Scholar⁴¹ will be accessed to search for grey literature. The search in Google search engine will be conducted by searching each set of search terms in the first 10 pages for the search hits. In addition, key authors known to publish in this area will be contacted for any additional published or unpublished work.

Stage 3: selecting studies

Prior to the study selection, the search results from all included databases will be merged, and duplication of studies will be removed by using reference management software (EndNote X9). The eligibility criteria will be defined using the Population, Intervention, Comparison, Outcome and Study (PICOS) design format to determine the studies to be included in this scoping review protocol (table 2).

Table 2.

Eligibility criteria using the PICOS (Population, Intervention, Comparison, Outcome and Study) design format to determine the studies to be included in this proposed scoping review protocol

Eligibility criteria	Description/characteristics
Population	Participants of all ages with idiopathic scoliosis are considered for inclusion in this scoping review. However, studies focusing on participants with other type of scoliosis are excluded.
Interventions	Orthotic treatments are included in this scoping review.
Comparators	No specific comparators are required for inclusion in the scoping review.
Outcomes	No specific outcomes are required for inclusion in the scoping review, as the purpose of the review is to determine the scope of the available evidence on orthotic treatments for individuals with idiopathic scoliosis.
Study design	Systematic reviews of experimental studies (eg, RCTs, pseudo-RCTs and pre–post studies) and meta-analyses are eligible for inclusion in the review. Systematic reviews that included experimental studies with observational or qualitative data collection and analysis are also eligible for inclusion in this scoping review.

RCTs, randomised control trials.

Before the screening process begins, all reviewers (WS, KP and SS) will be fully trained in how to properly screen studies according to the inclusion criteria. Reviewer agreement for screening will be calculated on a random sample of 20 publications using the κ statistic,⁴² and the agreement is defined as a statistic higher than 0.80. If agreement is <80%, the reviewers will discuss, clarify and refine eligibility criteria, as needed. The reviewer agreement testing process will continue until reviewer agreement reaches the minimum value (>0.80). The title, abstract and keywords of all identified papers will be initially assessed by two independent reviewers (WS and KP), with potentially eligible papers proceeded to full-text screening.

During full-text screening, the inclusion and exclusion criteria will be refined to enhance clarity and to improve specificity according to the reviewer’s objectives after discussion among the members of the research team. Two independent reviewers (WS and SS) will screen the full text of these papers, and reasons for exclusion will be recorded. Disagreements during full-text screening will be resolved via consensus, or by a third reviewer (KP). In the absence of full text for any article of interest for any reason, the authors will email the corresponding author to request for the full-text article. The process of article search and selection will be summarised using a PRISMA flow diagram.

Stage 4: Charting the data

All data will be collected electronically in a form developed using Microsoft Excel software (Microsoft Corporation, Redmond, Washington, USA) (table 3). The data extraction form will be developed and pilot tested by the reviewers (WS, KP and SS) prior to implementation, after which the form will be further refined to enhance accuracy, consistency and efficiency. Double data extraction will be conducted for the first 10 articles by two reviewers (WS and SS). Among the three members of the research team, the iterative process will again be employed to improve and finalise the data extraction form.

Table 3.

Study details and characteristics extraction

Domain/subdomain	Description
General document details
1.1 Publication year	Year of publication
1.2 Country and location	Country of publication
Study references
2.1 Research objective	What were the research objectives?
2.2 Research questions	What were research questions in the systematic review?
2.3 Context/setting	What was the context/setting of this study?
2.4 Orthotic treatment	What were orthotic designs/treatments?
2.5 Outcome	What were the main outcomes of interest?
2.6 Important results	What were the main results of the study? Were there any important subgroup analysis?
2.7 Limitations	What were the limitations of this study?
Grey literature references
3.1 Target audience	Was there a target audience for the specified grey literature?
3.2 Context/setting	What was the context/setting of the specified grey literature?
3.3 Orthotic treatment	What were orthotic designs/treatments?
3.4 Outcome	What were the main outcomes of interest?
3.5 Important results	What were the main results of the study? Were there any important subgroup analysis?

There will be a training session to trial and to ensure the common understanding of the data extraction process. Two independent reviewers (WS, SS) will complete the data extraction process for all eligible studies, and a third independent reviewer (KP) will subsequently check for any omitted data. Disagreements will be resolved by consensus and consultation with a third reviewer (KP) if necessary and as needed.

Since the objective of this scoping review is to determine the overall extent of conducted systematic reviews and the range of research undertaken, the following data will be extracted:

1. Systematic review characteristics (ie, publication year, objective of the study, search strategy and type of included studies).

2. Participant inclusion criteria (ie, age, gender/sex, condition, region/country, ethnicity and socioeconomic status).

3. Intervention/comparators inclusion criteria (ie, spinal orthotic treatment (orthotic design, materials, wearing time), other conservative treatments included (all types, or a subset)).

4. Outcome inclusion criteria (ie, Cobb angle, pain, function, quality of life, surgical rate, cost of treatment).

5. Systematic review findings (ie, number of included studies and presentation of findings, type of included study).

Critical appraisal

The methodological quality of included systematic reviews will be evaluated using the Assessing the MeaSurement Tool to Assess systematic Reviews Version 2 (AMSTAR-2)⁴³ critical appraisal tool by one reviewer (SS). In this scoping review, the 16-item AMSTAR-2 tool will be applied with seven critical domains and nine non-critical domains (table 4). The AMSTAR-2 tool provides an overall rating that reflects the weaknesses in critical domains. Reviews were rated as high (defined as no critical flaws with 0 or 1 non-critical flaw), moderate (no critical flaws with ≥1 non-critical flaw), low (one critical flaw with/without non-critical weakness) or critically low (>1 critical flaw with/without non-critical weakness).

Table 4.

Critical and non-critical items according to the AMSTAR-2 critical appraisal tool

Critical items

Non-critical items

Protocol registered before commencement of review Adequacy of the literature search Justification for excluding individual studies Risk of bias from individual studies being included in the review Appropriateness of meta-analytical methods Consideration of risk of bias when interpreting the results of the review Assessment of presence and likely impact of publication bias

PICO used for research question/inclusion criteria Justification of study design inclusion Study selection completed in duplicate Data extraction completed in duplicate Adequate description of included studies Sources of funding of included studies Impact of risk of bias on meta-analysis or other evidence synthesis assessed Satisfactory explanation and discussion of heterogeneity of results Conflicts of interest of authors declared

AMSTAR-2, Assessing the MeaSurement Tool to Assess systematic Reviews Version 2; PICO, population, intervention, control group and outcome.

Stage 5: collating, summarising and reporting the data

A quantitative analysis will be undertaken to report the number of studies for each of the data extraction categories: systematic review characteristics, participant inclusion criteria, intervention/comparator inclusion criteria, outcome inclusion criteria and review findings. In addition, the results will be presented according to the determined methodological quality (high/moderate, low and critically low) as assessed by the AMSTAR-2 critical appraisal tool.

Direct content analytic approach⁴⁴ with an initial deductive framework⁴⁵ will be used for evidence synthesis, which will allow flexibility for inductive analysis if refinement or development of new categorisation is needed.

In instances were reviews contain a mix of narrative and quantitative data, results from meta-analyses will be prioritised over count data or study-by-study data. The extraction and reporting of data results will be performed according to the data extraction form and will not involve an in-depth evaluation, which is appropriate for a scoping review. Review authors’ conclusions and/or recommendations will be extracted and reported narratively. The PRISMA-ScR guidelines will be followed in the preparation of the final report.³⁹

Stage 6: consultation

Experts who specialise in orthotic management for scoliosis will be consulted during preparation of the scoping review protocol to help determine the inclusion criteria and to identify grey literature. Findings will also be discussed.

Patient and public involvement

None.

Ethics and dissemination

Ethical approval and written informed consent were not obtained for this scoping review protocol proposal due to the fact that no patient data were collected, analysed or published. The results of this study will improve our ability to analyse previously published data specific to AIS, which will improve orthotic management of patients with AIS. The final report will be presented at relevant conferences and submitted to a peer-reviewed journal for publication.

Ethics statements

Patient consent for publication

Not applicable.