4. Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach

Munn, Z., Peters, M.D.J., Stern, C. et al. Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Med Res Methodol 18, 143 (2018). https://doi.org/10.1186/s12874-018-0611-x

Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach - BMC Me

건강, 의학 관련 연구에서는 review연구의 필요성이 높기에 각 synthesis reviews 종류가 다양하고 구체적이고 각 목적에 맞는 연구가 요청되는 것 같아. 하지만, 우리 분야에서 철학적 논의나 경험적 연구를 포함하는 경우가 많아 review 연구의 종류를 엄격하게 구분하거나 선도하지는 않는 것 같아. 그럼에도 모든 연구의 기초 과정인 literature review를 조금 더 체계적으로 할 수 있으니 꼭 필요한 과정인 것 같아.

언제 scoping review를 써야할까?
결국 Scoping review는 그 분야에 어떤 증거들이 있는지 확인하고/ 개념적 정의를 분명히 하거나 / 어떻게 연구가 진행되었는지 조사하고 / 개념에 관련된 특징을 확인하거나 / systemic review의 사전 연구로 하거나 / knowledge gaps를 확인하기 위해 진행됨. 그리고 아래 Table1에서 구분하고 있는 것처럼 서로 다른 기준을 가지고 있어.

Background
- Scoping reviews are now seen as a valid approach in those circumstances where systematic reviews are unable to meet the necessary objectives or requirements of knowledge users.
- The purpose of this article is to provide practical guidance for reviewers on when to perform a systematic review or a scoping review, supported with some key examples.

Indications for systematic reviews
1. Uncover the international evidence
2. Confirm current practice/ address any variation/identify new practices
3. Identify and inform areas for future research
4. Identify and investigate conflicting results
5. Produce statements to guide decision-making

Indications for scoping reviews
1. To identify the types of available evidence in a given field
2. To clarify key concepts/ definitions in the literature
3. To examine how research is conducted on a certain topic or field
4. To identify key characteristics or factors related to a concept
5. As a precursor to a systematic review
6. To identify and analyse knowledge gaps

Deciding between a systematic review and a scoping review approach
- If the authors have a question addressing the feasibility, appropriateness, meaningfulness or effectiveness of a certain treatment or practice, then a systematic review is likely the most valid approach
- A scoping review aims to provide an overview or map of the evidence. Due to this, an assessment of methodological limitations or risk of bias of the evidence included within a scoping review is generally not performed.
(방법적 한계 또는 증거의 bias 위험은 일반적으로 수행되지 않음. practice의 함의를 주는 것이 필요하지 않을 수 있음. 이러한 함의는 치료 또는 정책 결정의 관점에서 공고한 가이던스를 준다는 점에서 한계가 있을 수 있음. ) 
- When we compare this to systematic reviews, the provision of implications for practice is a key feature of systematic reviews and is recommended in reporting guidelines for systematic reviews.
(The provision of implications for practice라는 부분이 차이점! Systemic review는 주는게 목적이고 scoping review는 안주는 거. 근데, knowledge gap을 찾는 과정이랑은 다른걸까? 특정한 질문의 답을 안한다는 점에서 그렇고 전반적인 리뷰를 통해서 어디가 잘 안됐구나를 파악하는 거니까)

Exemplars for different scoping review indications
- To identify the types of available evidence in a given field
- To clarify key concepts/definitions in the literature
- To examine how research is conducted on a certain topic
- To identify key characteristics or factors related to a concept
- As a precursor to a systematic review
- To identify and analyze gaps in the knowledge base

Discussion
- A key difference between scoping reviews and systematic reviews is that in terms of a review question, a scoping review will have a broader “scope” than traditional systematic reviews with correspondingly more expansive inclusion criteria. In addition, scoping reviews differ from systematic reviews in their overriding purpose.

- Traditional literature review:
    : reviews. Traditional literature reviews have been used as a means to summarise various publications or research on a particular topic for many years.
    : These types of reviews can be considered subjective, due to their substantial reliance on the author’s pre-exiting knowledge and experience and as they do not normally present an unbiased, exhaustive and systematic summary of a topic.
     : If traditional literature reviews are contrasted with scoping reviews, the latter:
       
Are informed by an a priori protocol
       
Are systematic and often include exhaustive searching for information
       
Aim to be transparent and reproducible
       
Include steps to reduce error and increase reliability (such as the inclusion of multiple reviewers)
       
Ensure data is extracted and presented in a structured way

- Concept Analysis
- the production of evidence maps
- Rapid reviews

이러려고 하지 말아라
- in order to avoid the critical appraisal stage of the review and expedite the process, thinking that a scoping review may be easier than a systematic review to conduct.
- in order to ‘map’ the literature when there is no obvious need for ‘mapping’ in this particular subject area.
- with very broad questions as an alternative to investing the time and effort required to craft the necessary specific questions required for undertaking a systematic review.

 

Abstract

Background: Scoping reviews are a relatively new approach to evidence synthesis and currently there exists little
guidance regarding the decision to choose between a systematic review or scoping review approach when
synthesising evidence. The purpose of this article is to clearly describe the differences in indications between
scoping reviews and systematic reviews and to provide guidance for when a scoping review is (and is not)
appropriate.

Results: Researchers may conduct scoping reviews instead of systematic reviews where the purpose of the
review is to identify knowledge gaps, scope a body of literature, clarify concepts or to investigate research
conduct. While useful in their own right, scoping reviews may also be helpful precursors to systematic reviews
and can be used to confirm the relevance of inclusion criteria and potential questions.

Conclusions: Scoping reviews are a useful tool in the ever increasing arsenal of evidence synthesis approaches.
Although conducted for different purposes compared to systematic reviews, scoping reviews still require rigorous
and transparent methods in their conduct to ensure that the results are trustworthy. Our hope is that with clear
guidance available regarding whether to conduct a scoping review or a systematic review, there will be less scoping
reviews being performed for inappropriate indications better served by a systematic review, and vice-versa.