Needles in Haystacks: Part 1: what sort of needles are we looking for?

For a good many of us, searching for information on a topic involves typing a word or phrase into Google and scrolling through the millions of hits! Searching for studies to include in a systematic review is a rather more rigorous process!  This two part blog will give you a flavour of what is involved.

Searches in a systematic review must aim to retrieve all the relevant evidence about the research question and follow a specific methodology, so that, if necessary, the search could be reproduced.  However, they also need to be conducted within the budget, time and resources available for the project. As Information Specialist for the project this is my responsibility.

My first job was to devise a search strategy that would be capable of identifying all the relevant studies. The medical literature is vast and indexed across a considerable number of bibliographic databases so it is important to be clear what you are searching for. Searches in a systematic review are based on the research question which is composed of four elements. For this review:

• Population is people with knee instability related to a neuromuscular disease or central nervous system disorder
• Intervention is orthotic devices
• Comparator is any used
• Outcomes  are any investigated

The main challenges of this project are the number of diseases and conditions of interest and the number of possible orthotic devices. Studies can be indexed very differently on different databases so it is important to think of all the terms that could be used to describe the devices. The clinical experts on our Advisory Group provided valuable input on the names of all the possible relevant orthotic devices, so we are confident that we will locate the relevant studies.

Because there are many, diverse neuromuscular diseases and central nervous system conditions, we could possibly miss some if we were to list them in our searches, even with clinical advice. It would make searches very long, unwieldy and time-consuming. Instead we plan to concentrate on finding studies that describe using an orthotic device to deal with knee instability. For the same reasons, the comparators and outcomes have not been included in the search.

Blogger: Rocio Rodriguez-Lopez