Types of scientific literature reviews

Why is reviewing the scientific literature important?

Today, scientific knowledge is progressing at an accelerated pace and is constantly being updated. This translates into a rapid increase in the number of publications, making it increasingly difficult to access up-to-date, clear, and unified knowledge on a given topic. But how can we keep on top of this information?

Read this entry to find out!

What is a scientific literature review?

A literature review is a type of study that allows us to analyse, synthesise, and understand the existing evidence on a specific topic. Literature reviews are fundamental to building a solid foundation for new research as well as for clinical practice, as they help identify the most relevant advances and knowledge gaps in a specific area. It is a form of secondary research — that is, it draws on data that have already been published.

As an occupational therapist, what can a literature review offer me from a clinical and research perspective?

From a clinical perspective

Reviews allow us to stay up to date on a topic, facilitating decision-making and enabling us to offer treatments that are current and evidence-based, in support of better clinical practice.

From a research perspective

They allow us to identify knowledge gaps and relevant aspects of a topic in order to propose new or improved areas of research. They also provide information on the methodology used in each area of study, including the assessment tools employed and the most appropriate methods of analysis.

Most common types of review

Most common types of review

A brief overview of the types of quantitative review is provided below. At the end of this entry you will find bibliographic references for further reading on each type, as well as on the different classification systems for literature reviews depending on the author, such as Paré et al. (2015) or Amog et al. (2022).

Narrative review

This type of review aims to provide a summary of the literature on a broad topic. Unlike systematic reviews, it does not necessarily require an explicitly stated research question, inclusion and exclusion criteria, or a documented search strategy. Furthermore, since the process by which articles are selected is not specified, it is subject to the author’s own judgement. For this reason, narrative reviews should ideally be conducted by experts in the subject area.

scoping review

This type of review aims to provide a broad overview of a topic. It is centred on an exploratory research question, and its primary objective is to identify key concepts, types of evidence, and research gaps related to a specific field of inquiry.

rapid review

This type of review aims to quickly gather evidence to inform a specific intervention or decision. It is similar to a systematic review but omits certain steps in the review process.

umbrella review

Also known as a “review of reviews,” this type of review aims to build a rigorous overview of a topic by drawing on existing reviews in the area. A substantial body of evidence on the topic must already exist in order to carry out this type of review..

Systematic review

This type of review aims to analyse a topic in depth. It is a form of knowledge synthesis that seeks to gather all available information meeting pre-established inclusion and exclusion criteria, in order to answer a specific research question. Systematic methods are used to minimise bias and yield more reliable results — for example, through paired assessment of articles and the involvement of a third party to resolve discrepancies. As such, a systematic review allows conclusions to be drawn and evidence-based decisions to be made. The methodology must clearly specify the process for selecting and assessing bias in the included articles, since this process should be replicable. Finally, it is worth noting that the estimated time required to conduct a systematic review is one to two years.

Meta-analysis

This is a type of statistical analysis that allows quantitative data from a systematic review on a specific topic to be pooled. It uses statistical techniques to provide a quantitative estimate of the evidence.

Differences between a systematic review and a meta-analysis

Both types of study aim to provide a comprehensive overview of a topic. However, while a systematic review focuses on gathering and synthesising evidence in a qualitative way, a meta-analysis goes a step further by using statistical techniques to provide a quantitative estimate of the evidence summarised by a systematic review.

It should be noted that a meta-analysis cannot always be incorporated into a systematic review, as — depending on the topic and the degree of similarity between the included studies — data pooling may or may not be feasible. However, a systematic review is always the prerequisite for a meta-analysis; the latter cannot exist without the prior systematic process of reviewing and compiling the articles.

Differences between a narrative review and a systematic review

A narrative review is more flexible and less rigorous than a systematic review. While a narrative review may be influenced by the author’s perspective and does not follow a precise or detailed process, a systematic review follows a thorough procedure that includes inclusion and exclusion criteria and an assessment of bias in the included studies. A systematic review is reproducible; a narrative review is not.

But does being at the top of the evidence pyramid mean that all systematic reviews are high quality?

The answer is no. Conducting a systematic review does not guarantee that it has been carried out to quality standards and free from bias (https://hacto.umh.es/2024/04/11/tipos-de-errores-en-los-estudios-de-investigacion/)      The primary research synthesised within it may itself be of poor quality, in which case the systematic review will be too. It is also important to always read any scientific article critically (https://hacto.umh.es/2023/05/22/lectura-critica-a-traves-de-las-guias-caspe/).Here are some of the situations you may encounter:

• A systematic review may be methodologically sound but draw on articles with weak evidence. In this case, the content of the review will be of low quality and cannot be directly applied to our context with confidence.
• Alternatively, systematic reviews may contain methodological errors — for example, having been carried out by a single person for the search, selection, and assessment of the included studies. Reviews with unclear inclusion and exclusion criteria, or a search limited to very few databases, may also be found; in such cases, the results and conclusions included may not be entirely reliable.

So, what will determine which type of review to conduct?

• The type of research question you are seeking to answer.
• The purpose of the review (summarising a specific topic, gathering information on a broad area, etc.).
• The type and quantity of studies available on the topic..
• The skills, resources, and experience of the team conducting the review.

Examples applied to occupational therapy

Below are some examples of reviews relevant to occupational therapy practice. At these links, in addition to reading and consulting the study itself, you will find that the InTeO Group has conducted a critical appraisal of these articles and included additional relevant information for each review type (see the TOCrítico section of our website):

• Scoping review: https://hacto.umh.es/2024/07/17/art-interventions-for-children-with-autism-spectrum-disorder-a-scoping-review/
• Narrative review: https://hacto.umh.es/2023/11/22/habilidades-neurocognitivas-en-individuos-con-sindrome-de-down-una-revision-narrativa/
• • Systematic review: a critical appraisal of the following review article will be available shortly “Multisensory stimulation to promote feeding and psychomotor development in preterm infants: A systematic review” (https://pubmed.ncbi.nlm.nih.gov/35934665/).

Useful resources and references

Further information on the classification of literature reviews can be found in:

• Paré et. al (2015) https://www.sciencedirect.com/science/article/pii/S0378720614001116
• Amog et. al (2022) https://www.sciencedirect.com/science/article/abs/pii/S0895435622000658

We also recommend Right Review, a useful tool to help determine which type of review to conduct based on a checklist: https://rightreview.knowledgetranslation.net/.

• • Further reading on how to conduct a systematic review: https://pubmed.ncbi.nlm.nih.gov/30089228/

• • Finally, here is a link to another entry in the PublicaTO section, where you can learn more about the Cochrane Database of Systematic Reviews: https://hacto.umh.es/2024/02/28/2421/

Noce, M. P., & Campos Sánchez, I. (2025, marzo 20). Types of scientific literature reviews. PublicaTO – Scientific Skills in Occupational Therapy by InTeO.  https://hacto.umh.es/2025/02/04/tipos-de-revisiones-de-la-literatura-cientifica/