● The original sentence is an absolute claim that does not allow for any error by the authors.

● Including a phrase such as “To our knowledge” to the sentence explains to the readers that the authors have tried their best to search for previous reports on similar cases, but that their search may not be complete.

● “To the best of our knowledge” can also be used, but as it is more wordy, this would depend on the word count and the general balance of the text.

● “We believe that” is another phrase that could be used here, although it may have a slightly philosophical connotation, as it expresses the authors’ feelings of truth rather than knowledge.

● The phrase “to date” at the end is not hedging, but it is also an important phrase to use in manuscripts, as it stresses that the information applies at the time the manuscript is being written, and may not be true at subsequent times, such as when a reader is actually reading the manuscript.

● This example was taken from a cover letter that we edited for submission of a manuscript, rather than the manuscript itself. We are introducing this example here, as cover letters are also very important when researchers try to get their manuscripts reviewed and published in journals, particularly in the more competitive journals, in which a high percentage of manuscripts get rejected by the Editor.

● Adding “We believe that” to this sentence stresses that this is the opinion of the authors of the manuscript being submitted, and is not a “fact” that the authors are trying to force the Editor to accept.

● “We feel that” is also a phrase that can be used in sentences such as the above. It expresses a weaker opinion, so the authors should try to decide on which is more appropriate for their particular opinion.

● We also often see the phrase “We think that” being used in similar sentences. However, “think” has a connotation of just a physical process of the brain working, rather than expressing an opinion, and is hence not recommended for such phrases in scientific manuscripts.

● The modal verb “might” that expresses uncertainty was included in this sentence, as from the results of the study it was clear that this sentence was stating a speculation rather than a fact.

● It is important to note that hedging is not always required. For example, in the above sentence, if it is clear from the research results, etc., that the high prevalence of XX affects the prevalence of YY disease in the Japanese adult population, the original sentence would be more favorable. Thus, we advise non-native English-speaking researchers to proofread their manuscript, going over each of the statements, and think about whether the statement can be considered a fact, in which case hedging is not required, or whether it is only a possibility or an idea, in which case hedging would be favorable.

● Although scientific research is usually performed to “prove” a hypothesis, it is important for non-native English-speaking researchers to understand that this word is rarely used in scientific writing.

● For example, in the above sentence, although the new therapy XX may be effective, it is not clear whether it is truly completely safe. Research may find many years subsequently that the treatment has problems, or that it is in fact not safe. Therefore, it is more favorable for a writer to avoid the word “prove” in scientific writing, and use alternative hedging words, such as “suggest”.

● The verb “appear to” is also often used in hedging to express uncertainty.

● In the above sentence, if it is an accepted fact that XX symptoms increase with age, the original sentence would be appropriate. However, in this case, as well as in most cases in medicine and science, such a phenomenon has some uncertainty; for example, XX symptoms do not increase in every single patient. Therefore, it is safer to use hedging verbs, such as “appear to”.

● Another phrase that could be used in the above case is “seem to”. Both are often used interchangeably to explain how something looks, but “appear to” may have a connotation of how something may look visually.

● In the original sentence above, the authors use hedging to soften their claim using “suggest,” to say that their claim is not absolute. They have even included the phrase “but further studies are warranted” at the end, which further explains that the authors consider their results to be only a possibility at the time of writing.

● However, the authors also include the hedging word “might”. This can be considered to be excessive hedging, as they are saying that the possibility that they “suggest”, “might” be a possibility.

● The sentence would become clearer if as shown in the first revision, the first hedging word “suggest” is changed to “demonstrate” to make a more absolute claim, or as shown in the second revision, the second hedging phrase “might decrease” is changed to “decreases” to make a more absolute statement.