What is a central message?
The central message is the ‘take-home’ or ‘take-away’ message that expresses how your findings contribute to the field of interest. The central message should indicate two things. First, whether the main study aim (or purpose) was accomplished. Second, how that finding might be applicable to the ‘big picture’ (i.e., its clinical or research relevance). These statements are best written in two sentences, to avoid an excessively long sentence. Here we discuss determining a central message for a scientific article.
Coming up with a central message for your research can be difficult. You have to relate a single, key finding to a large, typically complex field of interest. Moreover, your central message must be reasonable, but also arouse the reader’s interest. In crafting a central message, you must also consider the study design. The take-home message will be different for a case study, an original research/clinical study, and a review. The central message is typically placed in the Conclusion section. However, because it relates to the main purpose of the study, it may also appear at the end of the Introduction.
Most journals expect the central message to be a single sentence or a few sentences that guide the reader in how to understand what the results mean. Therefore, it must logically stem from the results. The reader typically wants to know why they should care about your findings. Therefore, you need to consider the broad implications of your key findings. The biggest mistake in crafting a central message is to summarize what you did.
The central message should target a knowledge gap
The central message should target a knowledge gap in the existing literature. Therefore, it behooves you to review the literature and discuss existing research/hypothesis/practices with others in your field. Throwing out your ideas to others can lead to questions and observations that hone your target to a specific knowledge gap or a specific hole in an existing hypothesis or generally accepted understanding. Your findings might support or refute a shaky hypothesis, or they might introduce a new feature that has not been considered previously.
Some findings may not point directly to a knowledge gap, but require some interpretation or some reasonable assumptions to clarify how it might fit into a given paradigm or pathway. In those cases, you must be careful to explain the logic of your assumptions and the conditions that might have influenced the findings. When the central message requires an assumption or interpretation, it’s OK to suggest future studies that might substantiate your interpretation.
The study design shapes the central message
- A case study should show something unique or rare: therefore, you can say it ‘reveals a unique aspect [of something]’ or ‘extends our understanding of [something]’;
- An original or clinical study might involve discovery, a comparison, or a new procedure (i.e., a ‘how to’ paper): therefore, you can say your results ‘identified’ or ‘elucidated’ something; your results ‘demonstrated that one thing was superior to another thing’, or that your results ‘demonstrated’, ‘validated’, or ‘established’ that this approach was ‘feasible’ or ‘more refined than an existing approach’ for the intended purpose.
- A review will focus on how an existing topic has developed. Therefore, you can say that the study ‘elucidated’ or ‘advanced’ a particular facet of the topic you are covering. The ‘facet’ should relate to the purpose of the review.
Relate your key finding to the study aim
The central message should indicate whether the study aim was accomplished; therefore, you should consider the purpose of the study.
- For physiological function or disease studies, the purpose is typically a to discover the cause of an observation or the effect of a manipulation;
- For a treatment or procedure study, the purpose is to determine the feasibility or advantage of a different approach;
- For discovery studies, typically the purpose is to test a new hypothesis; alternatively, you might endeavor to either challenge or support an existing hypothesis.
- For a review, the purpose is typically to highlight new developments in a field, or to determine whether a specific issue has been adequately addressed. Alternatively, a review might be focused on issues that remain to be addressed in a certain field.
- For a case study, the purpose is typically to provide more data on a rare condition or treatment.
Highlight the clinical or scientific implications of your findings
This statement typically proposes how the key findings might be applied. Some examples are:
- Clinical results might be useful in the diagnosis, treatment, or management of a disease.
- Research results might inform drug development by suggesting a candidate target or they might increase our understanding of a particular pathway or disease process.
- ‘How to’ studies can show the advantages of a novel, modified, or repurposed research technique.
- Clinical trials might show or compare treatment efficacy, adverse events, and/or survival outcomes for a particular disease.
- Population studies can provide various insights; for example:
- Disease prevalence, which indicates the urgency of developing novel treatment approaches;
- Patient characteristics or factors that affect disease susceptibility, which suggest methods for targeting a particular patient subgroup;
- Patient characteristics or factors that affect drug efficacy, which suggest methods for selecting patients for a particular treatment
Wording the central message
It is important to take care in wording the central message, because certain words can trigger a negative comment from reviewers. Don’t make unrealistic claims, but don’t be too pedantic or trivial. You want to highlight the potential impact of your finding, without overdoing it.
The level of evidence sets the tone of the central message
A common pitfall is failing to acknowledge the level of evidence of your findings. Reviewers are quick to criticize a take-home message that is overstated, particularly when interpretations or assumptions are involved. A strong central message should be supported by solid evidence and control experiments that rule out alternative explanations. Words like ‘showed’, ‘demonstrated’, or ‘indicated’, convey a high level of evidence. For example, the central message from a randomized controlled study could begin with the words “This study demonstrated that…”.
However, when experiments have not been thoroughly controlled or the relevance of the results requires some assumptions, the central message should reflect some degree of uncertainty. Words like ‘might’, ‘suggest’, and ‘could’ reflect less solid levels of evidence. For example: “Our findings suggested that the leptin pathway might be involved in fat accumulation”.
Conversely, it is not advisable to understate the central message, because you can undermine your findings. For example, in some cases, the authors convey uncertainty by listing the conditions that the findings depended on. For example “This study suggested that X might be effective for treating IBD in an obese population under 40 years old in Norway, during winter. These conditional statements are unnecessary and they tend to cast doubt on the reliability of the results.
Keep in mind that you have already listed the study limitations and described the setting, conditions, and controls. Therefore, it is better to simply state “This study suggested that X was effective for treating IBD in [some] obese individuals.” In this case, adding “some” is important when the study population is a selection of a broad population. It is not necessary, when the study population is representative of a broad population.
Claiming a “first in kind” study
Note that the phrase “This study was the first to…” is commonly used to express the unique nature of a study. This phrase highlights the novelty of your study, but be aware that some journals forbid the use of this phrase or any phrase that expresses the uniqueness or novelty of a study, including phrases like “This study was novel or unique…” or “No other study has…”.
Expressing the clinical or scientific relevance of key findings
Finally, you must indicate the clinical significance or research relevance of your key finding. This sentence suggests how the key result could be useful in future applications or how it might guide future studies in the of the field of interest. Therefore, this sentence should grab the interest of the reader. For example: “Our findings suggested that X might serve as a novel target in the development of future pancreatic cancer treatments.”
Again, be careful not to overstate the significance. This is best done by avoiding generalities. Indicate an interesting aspect of the finding, like “X could be useful in…”, “X might facilitate…” “This finding has contributed to our understanding of…”, or “X might serve as…”. Then, relate it to a specific field of interest.
The more specific you are in this statement, the easier it will be for the reader or reviewer to accept. A failure to be specific in this statement could result in a negative assessment, because if your take-away message is too inclusive, it might be perceived as too far-fetched (i.e., not realistic). Conversely, when it is too general, it might be considered too mundane (i.e., unimaginative).