Understanding the Literature Search Process

A literature search is a crucial phase in many projects such as proposals for literature review or a scientific research study. It helps us gather, scrutinize, and understand what has already been published about a specific topic. This not only saves resources and time but also gives a foundation for the new research or review. At Rx Communications, our expertise in conducting comprehensive literature searches and reviews has led us to develop a 4-step process to help researchers get the results they desire.

Step 1: Clearly Define the Research Question

The initiation of any literature search revolves around a well-defined research question. This stage is crucial as it lays the groundwork for the entire literature review or research study. Here's a deeper look into this process:

Identifying the Purpose

Understanding the purpose of the research is the cornerstone of defining the research question. This could range from informing future drug developments, clinical trials, in-licencing opportunities, or health technology assessment (HTA) submissions. You need to consider if the search will form a foundation for your own research or perhaps be used to inform business decisions. It's crucial to understand the intended use of the search results, as this shapes the way the research question is formulated.

Framing the Question

Once you've identified the purpose, the next step is to frame the question. This requires critical thinking and meticulousness, and can often involve a back-and-forth process with all stakeholders involved. The question should be specific enough to guide the search but broad enough to allow the exploration of related subtopics. For example, a question like "What are the effects of drug X on condition Y?" could be broken down into sub-questions that consider different aspects such as the effect on different age groups, side effects, long-term effects, etc.

Consider the Scope and Complexity

Understanding the scope and complexity of the question is also critical. A broad question could result in an overwhelming amount of literature, while a narrow question could yield too few results. The complexity of the question can also dictate the resources needed to conduct the literature search.

Budgeting and Resources

Another important aspect is to consider the budget and resources available for the literature search. A more comprehensive search would naturally require more resources, while a narrower question might suffice for a limited budget. Making a judgement call on whether a general indication is sufficient or if a detailed analysis is needed, based on the resources available, is crucial at this stage.

Ensuring an Unbiased Approach

The research question should also allow for an unbiased and comprehensive literature search. It's important to avoid 'cherry picking' data, or excluding unfavorable results or competitor’s pivotal studies. The aim should always be to present an accurate and fair overview of the current literature on the topic.

In conclusion, defining the research question forms the backbone of the literature search process. It provides the guiding framework which will lead the research process in the subsequent steps. It's a careful balance of specificity and breadth, and requires a clear understanding of the purpose, scope, complexity, budget, and resources available.

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Step 2: Selecting Appropriate Literature Resources

Choosing the right databases or literature resources to conduct your literature review is paramount. The resources chosen will greatly impact the quality and breadth of information you collect. Here's an expanded explanation of the second step:

Identifying Relevant Databases

There are hundreds of databases available, each catering to different fields of study. In the medical and scientific field, key databases include MEDLINE, EMBASE, SCISEARCH, and BIOSIS. However, the selection of databases should be tailored to your specific research question. For example, for health economics topics, the HEED bibliographic database might be more suitable; for safety data, TOXFILE could be useful.

Understanding Database Specifics

Understanding the specifics of the database you're using is also crucial. This includes understanding the search engine used by the database, the structure of the database, its strengths and weaknesses, and the way it indexes articles. For instance, knowing that PubMed and MEDLINE are not exactly the same, and a switch from one to the other can impact your search results, is essential.

Considering Open Access Resources

Open access resources, such as PubMed, should also be considered, as they can often provide a wealth of information at no cost. However, keep in mind that open access resources might not always have the most comprehensive collection of articles. Depending on the research question, they might only cover 60-80% of the available published full papers.

Incorporating Grey Literature

In some cases, it might be beneficial to consider including grey literature in your search. Grey literature includes reports, theses, conference proceedings, and other materials that have not been published in traditional academic journals. Incorporating grey literature can help ensure a more comprehensive search, and prevent publication bias.

Handling Duplicates

When using multiple databases, duplicate results can occur. It's important to use a search engine that allows for the removal of duplicates to save costs and time. Manual de-duplication might be necessary when databases or sources are added that are not accessible by the main search engine.

Benchmarking Resources

It can be useful to benchmark the chosen databases and search engines against each other to understand their relative effectiveness. This can provide insights into the margin of error and inform any necessary adjustments to your search strategy.

In summary, the selection of literature resources should be tailored to your specific research question and field of study. Understanding the specifics of the databases, considering open access resources, incorporating grey literature, managing duplicates, and benchmarking the resources can greatly enhance the quality and breadth of your literature search.

Step 3: Crafting Effective Search Strings and Applying Limits

After defining your research question and identifying your literature resources, it's time to construct the actual queries that will be used to search these databases. This process involves creating appropriate search strings and applying useful limits to your search. Let's explore this process more thoroughly.

Understanding Search Strings

A search string is a combination of keywords, phrases, and operators (like AND, OR, NOT) that is entered into a database to find relevant articles. Building a good search string requires a solid understanding of the topic, synonyms or related terms, and how different databases interpret search queries.

Building a Comprehensive Keyword List

Begin by identifying the key concepts in your research question and generating a list of relevant keywords. Consider all possible synonyms, acronyms, and alternate spellings. This ensures a comprehensive search that doesn't miss out on relevant literature because of terminology differences.

Using Boolean Operators

Boolean operators (AND, OR, NOT) can be used to combine or exclude keywords in a search, creating more focused and productive results. For example, "cancer AND therapy" will return articles that include both terms, while "cancer NOT therapy" will exclude any articles that mention therapy.

Applying Truncation and Wildcards

Truncation and wildcard symbols can be used to search for all variations of a word. For instance, "therap*" could retrieve therapy, therapies, therapeutic, etc. Wildcards replace a character within a word, such as "wom?n" retrieving both woman and women. However, usage varies across databases, so understanding the specific rules of your chosen database is key.

Testing the Search Strings

Test the search strings iteratively, adjusting terms and their order, to ensure they yield the most relevant results. This process requires experienced personnel who understand the search engine requirements and the way each bibliographic database is indexed.

Deciding on Search Fields

Determining which fields to search within the database is also crucial. Searching in title, abstract, or full text fields will yield different results. A full text search might generate more results, including non-relevant ones, but it might also yield important articles that would have been missed otherwise. Depending on the research question and available resources, you might decide to search in one or more of these fields.

Applying Limits

Applying limits, such as date range, language, or article type, can help refine your search. However, too many limits can exclude relevant articles, while too few can lead to an overwhelming number of results. Striking the right balance is essential.

In summary, creating effective search strings and applying appropriate limits are essential components of a literature search process. They require a thorough understanding of the research question, the chosen databases, and the principles of database searching.

Step 4: Defining Inclusion and Exclusion Criteria and the Role of a Pilot Phase

The last step in a literature search process is defining the inclusion and exclusion criteria, which help you to decide which studies to include in your literature review. Here's a detailed look at how to approach this crucial step:

Setting Inclusion and Exclusion Criteria

Inclusion and exclusion criteria are the principles and guidelines that determine which studies should be included in or excluded from your literature review. These criteria are typically defined a priori (i.e., before you start your literature search) and should be based on the research question.

Inclusion criteria might be specific characteristics that a study must have to be included in the review. These could relate to the study design (such as randomized controlled trials, cohort studies, etc.), the population studied (such as adults, children, people with a specific disease, etc.), the intervention or exposure, the outcomes measured, and the language or year of publication.

Exclusion criteria are those characteristics that disqualify a study from being included in the review. These may include studies with a high risk of bias, studies that do not include relevant outcomes, or studies that are duplicates of others already included.

It is essential to record the reasons for exclusion of articles, particularly in a systematic review, as it adds to the transparency of the process.

Utilizing a Pilot Phase

A pilot phase can be a useful tool to test your inclusion and exclusion criteria. In this phase, a small subset of articles is screened to check if the criteria are working as expected. This can help you identify if you're missing relevant studies or including irrelevant ones, allowing you to adjust the criteria before the full screening process begins.

Pilot testing has several benefits. It can provide an early indication of the feasibility of your literature search process and can help you refine your inclusion and exclusion criteria. It can also provide an opportunity to train and calibrate reviewers, ensure consistency among them, and estimate the time and resources required for the full review.

Documenting and Replicating the Process

It's important that the search methodology, including the databases searched, search strings used, and inclusion and exclusion criteria, are documented in a manner that can be replicated by other researchers. This ensures the transparency and reliability of your literature review.

In summary, setting inclusion and exclusion criteria, conducting a pilot phase, and documenting the process are integral to ensuring a robust and repeatable literature search. This meticulous approach aids in producing a comprehensive, unbiased, and reliable review of the existing literature.

The Role of a MedComms Agency in Literature Search

Navigating the complex landscape of literature search can be daunting, particularly for those without extensive experience or for organizations with limited resources. This is where a medical communications (MedComms) agency can play a pivotal role. MedComms agencies are equipped with experienced professionals who are proficient in conducting comprehensive and systematic literature reviews.

Benefits of Engaging a MedComms Agency:

• Expertise: MedComms agencies have teams of professionals skilled in conducting literature reviews. They understand how to craft effective search strings, apply appropriate limits, and meticulously screen articles for inclusion and exclusion.
• Time Efficiency: A literature search is time-consuming. Letting experts handle it can free up your team's time for other critical tasks.
• Quality: MedComms agencies follow rigorous standards, ensuring the quality of the literature search and review.
• Comprehensive Coverage: A professional agency has access to multiple databases and uses sophisticated search strategies to ensure no relevant literature is missed.
• Objective and Unbiased: Engaging a third party helps maintain objectivity and neutrality, reducing the risk of bias in the review process.

Choosing to delegate the literature search process to a MedComms agency not only ensures accuracy and thoroughness, but it also brings an element of external objectivity that enhances the credibility and value of the resulting review. As a result, the insights drawn from the reviewed literature can form a stronger foundation for your future research or decision-making processes.

In conclusion, these four steps serve as a guide to a successful literature review process. The process demands careful consideration at every step, from defining the research question to the selection of databases, constructing the search string, and setting the inclusion and exclusion criteria. At Rx Communications, our team is always ready to assist you in ensuring a thorough and effective literature search.

Need help navigating the literature review process? Our medical writing services provide expert support to ensure your review is thorough, accurate, and well-structured. Let us streamline your next project.

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