The intention of this essay is to critically appraise one paper of systematic review and one paper of narrative review by using CASP tool and then compare and contrast the difference between the two reviews. This assignment will start with by illustrating the types of literature review (systematic and narrative reviews) and the strengths and weaknesses for both. It will follow with the role of systematic and narrative reviews in the evidence based. Following this, critical appraisal will be discussed with the justification of the choosing tool. Finally, the choosing papers of systematic and narrative reviews will be appraised.
In the healthcare sector, reviews have always been considered as part of the healthcare profession. All specialists and professionals are required to collate knowledge with published evidence on a particular topic or question. Scientific reviews are studies which use database searches to retrieve results of research, and have as their goal and objective of a specific topic. Two main types of review articles are commonly found in the scientific literature: Systematic and narrative reviews. Each type of the review articles has its own purposes and charactristics (Rother, 2007).
Narrative review (NR) is a review which summarizes all of the primary studies tempered by years of practical knowledge from the reviewer’s personal experience. It aims to provide a broader picture and comprehensive background within a given topic. It is helpful to refine or to focus on broad question. It has the advantage of including a wide range of relevant information and years of experience from the author. This type of review is useful in developing a theoretical and conceptual framework (Kirkevold, 1997).
Although narrative reviews may benefit from having broad background information, they have many drawbacks. This review is built on the reviewer’s personal beliefs and experience. According to Torgerson (2003) expert opinion is considered the lowest type of evidence (bias). Moreover, NRs are not very explicit about the study assessment, integration, and also how the studies were selected. Thus, this type of review is not as a rigorous as it should be (Garg et al., 2008). Therefore, the inadequacies of narrative reviews make it necessary for establishing a new rigorous systematic approach such as systematic review.
Systematic review (SRs) is defined as “explicit, formulated, reproducible, and up-to-date summaries of the effects of healthcare intervention” (Egger et al., 2001; p. 2). It is conducted according an explicit and very well structured method. It includes a peer review protocol which is prepared by two reviewers who are experienced in a clinical area, and review methodology which minimizes the possibility of bias (Hemingway and Brereton, 2009). In addition, SRs are the process of identifying relevant studies according to the specifically focused questions, appraising the quality of the identified studies, summarizing the results, and presenting vital findings (Cook et al., 1997). Thus, it appears that SRs have the advantages of being more transparent than NRs.
Unlike narrative reviews which may be open to bias and subjectivity (Porta, 2008), SRs have more objective appraisal of the evidence and may thus SRs play a role to resolving uncertainty when original research and reviews disagree (Egger et al., 2001; Higgins and Green, 2008). They improve our understanding of inconsistencies among different studies (Cook et al., 1997) and may enhance the generalisability of findings (Glasziou et al., 2004). By using an efficient scientific technique, SRs also can counteract the need for further research studies and stimulate the timelier implementation of findings into practice (Lipp, 2005). Thus, they guide policy makers in the development of practice protocols (Cook, Mulrow and Haynes, 1997; Egger et al., 2001). SRs can also inform the research agenda by identifying gaps in the evidence (JBI, 2001) and generating questions that will shape future research studies (Handoll et al., 2008; Lipp, 2005). Apart from defining the boundaries of the known and unknown, SRs helps clinicians to avoid knowing less than has been proven (Cook, Mulrow and Haynes, 1997). Moreover, they provide definitive answers to clinical questions which may be uncommonly ascertained in a single study (Davidoff, 1995). Thus, Badget, O’Keefe and Henderson (1997) contend that SRs may promote learning as they minimise the time and effort required in reading individual research studies.