Week 3: Developing My Search Strategy for Meta-Analysis

This week, I moved from learning about meta-analysis methods to actively applying them in my research project. After gaining an understanding of the PRISMA guidelines and the structure of systematic reviews, I began developing a search strategy to identify relevant studies. I quickly realized that this process was more complex than I initially expected, because I needed to balance finding a sufficient number of studies with maintaining a clear focus on my research question across different databases.

One of the main challenges I encountered was creating a search string that accurately reflected my topic without being too broad or too narrow. My research examines how hypoimmunogenic gene editing influences immune rejection in lab-grown tissues derived from pluripotent stem cells for transplantation. When I tried to include every part of this question in a single search string, the results were very limited. In some cases, PubMed returned fewer than 10 papers, suggesting that my search was too specific and might have excluded relevant studies. However, broadening the search introduced a different problem. Using less specific terms or searching in databases like PubMed Central produced thousands of results. Many of these were not directly related to my research. To address these issues, I began refining my approach by concentrating on the core concepts of my research rather than trying to capture every detail in the initial search. I prioritized key elements such as induced pluripotent stem cells (iPSCs), transplantation or graft contexts, immune rejection outcomes, and gene-editing techniques. I also adjusted my use of Boolean operators, relying less on broad “OR” terms and using more precise “AND” combinations to keep the results relevant.

After obtaining a comprehensive set of articles from multiple databases, I began developing my inclusion and exclusion criteria for screening. These criteria further narrow down to the articles that help me answer my research question. For example, I set out to include studies on gene-edited pluripotent stem cell–derived tissues that report measurable immune rejection outcomes in transplantation or graft settings. In contrast, I will exclude studies that focus only on basic stem cell biology, do not involve gene editing, or do not report immune-related outcomes. Setting out these guidelines beforehand helps me speed up the screening process, as I start with a clear sense of what I do and don’t want in the articles.