Comments on abstract, title, references

● Is the aim clear? I think the article's objectives are clear ● Is it clear what the study found and how they did it? Yes it is the study is clear the finding of this study ● Is the title informative and relevant? Yes it seems informative ● Are the references: ● Relevant? Yes they are ● Recent? Some of them ● Referenced correctly? Yes ● Are appropriate key studies included? I see many key authors

Comments on introduction/background

Is it clear what is already known about this topic? From my point of view, the author is pretty clear about the content of the epidemiology definition up til 1979

Is the research question clearly outlined? The research question doesn't clearly outline in the introduction; however, the aim of the article is straightforward to answer an implicit question.

Is the research question justified given what is already known about the topic? Yes because the epidemiology is a science who has evolved so quickly in the time

Is the process of subject selection clear? Yes the process of article selection( in this case ) is straightforward ● Are the variables defined and measured appropriately? Yes the variable defines with accuracy ● Are the study methods valid and reliable? I think the method is not completely valid and reliable ● Is there enough detail in order to replicate the study? No there is not enough detail

Is the data presented in an appropriate way? Yes it is ● Tables and figures relevant and clearly presented? Yes it does ● Appropriate units, rounding, and number of decimals? I guess so ● Titles, columns, and rows labelled correctly and clearly? Yes they are labelled correctly ● Categories grouped appropriately? Yes this happens according to the year ● Does the text in the results add to the data or is it repetitive? I don't think so ● Are you clear about what is a statistically significant result? Not because they don´t use a p-value instead of that use bayesian approach ● Are you clear about what is a practically meaningful result?

● Are the results discussed from multiple angles and placed into context without being overinterpreted? Yes the results are discussed from a broad point of view ● Do the conclusions answer the aims of the study? Yes because the conclusion wraps up the question that motivates this study ● Are the conclusions supported by references or results? Yes they are ● Are the limitations of the study fatal or are they opportunities to inform future research? I thought the limitations are opportunities for future research

Overall statement or summary of the article and its findings in your own words The article is about the changes in the concept of epidemiology in the lapse of forty years. From my point of view this quite remarkable because epidemiology is a young science because until the XIX century has developed as a proper field of science. I thought the definition of epidemiology could have evolved due to the last development in biomedical science so I agree that the effort to redefine epidemiology is worth it. Related to methods, in my opinion, is indicated a review of literature in order to gain a comprehensive perspective about the meaning of a concept. With respect to the result is a great number of result 102 definitions of epidemiology, so it is an indicator of the deep search doing by the team who write this article.

Overall strengths of the article and what impact it might have in your field The strengths of this article are the search in published literature and grey literature. The author search at least two indexes database as PubMed and ScienceDirect. The method to synthesize the literature was an analysis of content which I consider was the right option. The impact will reformulate the conception of epidemiology as a dynamic field inf particularly during the last forty years due to a changes in genetics, molecular biology and environmental science.

Specific comments on the weaknesses of the article and what could be done to improve it Major points in the article which need clarification, refinement, reanalysis, rewrites and/or additional information and suggestions for what could be done to improve the article.

1. A PRISMA flow chart will be useful to understand better the selection of the literature
2. I would like the author to explain more of about the bays factor
3. Although the methodology is coherent in the article, I would expect more structural qualitative analysis such as semantic relations
4. I would like the author could give the strongest conclusion such as the complement of the definition of epidemiology that has been accepted until 1978, this is helpful for readers of the article.