Within some fields there is an increasing tendency towards literature searches being required to be carried out as systematic reviews. There are specific requirements for a systematic review, and it is often a very time-consuming task. The following definition outlines the scope of a systematic review:
“A systematic review is a structured and pre-planned synthesis of original studies involving predefined research question, inclusion criteria, search methods, selection procedure, quality assessment, data extraction, and data analysis. No original study should deliberately be excluded without explanation, and the results from each study should justify the conclusion."
LUND, H., JUHL, C. & CHRISTENSEN, R. 2016. Systematic reviews and research waste. The Lancet, 387, 123-124.
Depending on time and resources, you should consider whether there is another type of review that might be better suited to your research project.
A systematic review is characterized by the following requirements being met:
There are several different types of review, of which the systematic review is just one. Read short descriptions of various review types and find references to relevant literature on the subject.
PICO is a model which helps you to formulate a focused question and create the basis for a literature search. The focused question helps to structure, define and delimit the literature search. The focused question can be grounded in the PICO model, which describes the 4 aspects of clinical questions:
P = the patient or problem being addressed
I = the intervention or exposure being considered
C = the comparison intervention or exposure where relevant
O = the clinical outcomes of interest
An example of a research questions could be: "Mentalization based therapy is an effective form of treatment for women with borderline personality disorder?"
If you used PICO to structure the question it might look like this:
In addition to PICO there are a number of other tools, such as:
Critical appraisal refers to the systematic analysis and assessment of research articles with the aim of assessing their reliability and quality. There are various checklists depending on the kind of study design employed by the article being assessed. The list below is not complete, but for inspiration:
Reporting standards have been developed with the aim of ensuring complete, accurate and transparent reporting of research studies.
If you only have time to tackle one single text, we recommend the article by Papaioannou et al., 2010.
Tackle your search process in a structured manner and organise your search in advance. You can minimise the risk of reproducing already existing research and have a greater chance of avoiding bias.