Use of Data Analysis Methods in Dental Publications: Is There Evidence of a Methodological Change?

Round 1

Reviewer 1 Report

I enjoyed reading your study. Here are some recommendations:

1) In Figure 1, please include the abbreviations in the footnotes but not at the beginning of the Figure.

2) Lines 173-175. The authors have written “The journals did not differ from each other in this respect: JD had an increased proportion of observational articles from 12.5% to 32.5%, JDR from 22.5% 174 to 32.5%, CR from 37.5% to 55.0%, AOS from 55% to 65%, and even CDOE from 72.5% to 85%”. Sometimes you use one number after dot, sometimes – nothing. It is recommended to present the numbers in a consistent way throughout the paper.

3) Line 176. “Table 2 presents the sample sizes of the reviewed studies”. The Table 2 presents not only the sample size, but also the distribution of study design that is discussed and mentioned earlier.

4) Line 177. The sentence “Only in JD was there a clear change from small studies to 177 studies with larger sample sizes” is recommended to correct.

5) In Figure 2, please give the transcript of abbreviations in the footnotes.

6) Line 205. “p-value of independent samples t-test was < 0.155”. = <???

7) Line 213. «... were not at the same level in” is recommended to correct.

8) Lines 232-233. The symbol of Spearman’s correlation coefficient is unclear.

9) From the Table 3, it is unclear what GAM means. Please give the transcript in the footnotes.

10) Line 266. Given the abbreviation of GEE is used only one time, it is recommended to delete it.

11) Discussion. The main results are recommended to present in line with the research questions formulated in Introduction

12) Conclusions. It is recommended to revise the conclusions. It is expected readers get answers on your research questions formulated in Introduction. The practical implication of the study is also important.

Overall, this is an interesting study.

Author Response

We thank the reviewer for the constructive feedback of our manuscript “Use of data analysis methods in dental publications: Is there evidence of a methodological change?". We have resolved the issues mentioned by the reviewer.

I enjoyed reading your study. Here are some recommendations:

1) In Figure 1, please include the abbreviations in the footnotes but not at the beginning of the Figure.

We have now moved the abbreviations into the figure legend below the figure. We hope this fits the journal style.

2) Lines 173-175. The authors have written “The journals did not differ from each other in this respect: JD had an increased proportion of observational articles from 12.5% to 32.5%, JDR from 22.5% 174 to 32.5%, CR from 37.5% to 55.0%, AOS from 55% to 65%, and even CDOE from 72.5% to 85%”. Sometimes you use one number after dot, sometimes – nothing. It is recommended to present the numbers in a consistent way throughout the paper.

Thank you. We report now all percentages with one decimal number.

3) Line 176. “Table 2 presents the sample sizes of the reviewed studies”. The Table 2 presents not only the sample size, but also the distribution of study design that is discussed and mentioned earlier.

We have added "also" to this sentence.

4) Line 177. The sentence “Only in JD was there a clear change from small studies to 177 studies with larger sample sizes” is recommended to correct.

We have corrected the typo.

5) In Figure 2, please give the transcript of abbreviations in the footnotes.

We have included explanation of abbreviations as footnotes.

6) Line 205. “p-value of independent samples t-test was < 0.155”. = or <????

We have deleted “<”.

7) Line 213. «... were not at the same level in” is recommended to correct.

We have corrected the typo.

8) Lines 232-233. The symbol of Spearman’s correlation coefficient is unclear.

We have now replaced the erroneous symbol with the correct symbol r.

9) From the Table 3, it is unclear what GAM means. Please give the transcript in the footnotes.

We have added “GAM = Generalized additive models” in the footnotes.

10) Line 266. Given the abbreviation of GEE is used only one time, it is recommended to delete it.

We have now deleted it.

11) Discussion. The main results are recommended to present in line with the research questions formulated in Introduction

We agree and are grateful to the reviewer for the helpful suggestion. We have now revised the research questions formulated in the introduction and the discussion section accordingly.

12) Conclusions. It is recommended to revise the conclusions. It is expected readers get answers on your research questions formulated in Introduction. The practical implication of the study is also important.

We have revised the conclusions to include the main findings and the practical implications of our study.

Overall, this is an interesting study.

Thank you.

Reviewer 2 Report

The paper is interesting and the treated topic falls into the Pubblicazione aim and scope.

Just some minor concerns about the methodology. Why do not extend the limit of the investigation to 2019?

I do not understand the choice limited to the five dental journal; authors stated that the choice can be related to the impact factor. I just wondering if the Indexing of each Journal could help a new key factor and parameter to be considered in that choice.

Overall The paper is readable and really interesting

Author Response

We thank the reviewer for the constructive feedback of our manuscript “Use of data analysis methods in dental publications: Is there evidence of a methodological change?". We have resolved the issues mentioned by the reviewers.

The paper is interesting and the treated topic falls into the Pubblicazione aim and scope.

Thank you.

Just some minor concerns about the methodology. Why do not extend the limit of the investigation to 2019?

We agree with the referee that the time span could be extended to 2019. We will review dental papers published in 2019 in our future study where our study aim is to evaluate the quality of statistical reporting in dental and medical papers.

I do not understand the choice limited to the five dental journal; authors stated that the choice can be related to the impact factor. I just wondering if the Indexing of each Journal could help a new key factor and parameter to be considered in that choice.

Thank you for drawing our attention to the additional criteria of choice of journals. To explain the use of journal indices we have added the following text: “All selected journals were indexed by Medline, Web of Science and Scopus which are the three most comprehensive indices of medical scientific journal articles.”

Overall The paper is readable and really interesting.

We appreciate this comment.

Round 2

Reviewer 2 Report

Authors made excellent job addressing all the reviewers requests and notes.