Epidemiology of Pediatric Meniscectomy: A Nationwide Study in Italy from 2001 to 2016

Round 1

Reviewer 1 Report

This is a well written paper of an interesting and relevant topic; namely meniscectomies in children.

The authors used a nationwide database of Hospital discharge codes to assess the incidence of this procedure during a long period. I Have a few minor remarks.

1.       What is the accuracy of the used database?

2.       The authors should add to the materials and methods paragraph that the incidence rate was also stratified per year, per age category, per sex.

Author Response

We would like to thank the reviewers for their helpful comments and their suggestions for improving our manuscript.  We have carefully revised our manuscript accordingly and hope that the changes are acceptable for publication. The changes made are itemized below with our comments (dark blue text) to the reviewer’s suggestions. Changes made in the text are highlighted in yellow in the original manuscript as well as reported below.

 

Response to Reviewer #1 Comments:

 

This is a well written paper of an interesting and relevant topic; namely meniscectomies in children.

The authors used a nationwide database of Hospital discharge codes to assess the incidence of this procedure during a long period.

 

Thank you very much for your appreciation of our manuscript.

I Have a few minor remarks.

1. What is the accuracy of the used database?

 

Thank you very much for your comments.

1. Hospital discharge records (Schede di dimissione ospedaliera - SDO) are the main tool for collecting official information on every patient discharged from public and private hospitals throughout the country, collecting medical and demographic information for calculating statistics on hospital utilization, and on the nature and treatment of illness among the hospitalized population. These data are highly accurate as they are based on national records and checked by the single hospitals. Several studies on different topics have been already published employing statistical data from Hospital discharge records (Schede di dimissione ospedaliera - SDO).

 

 

2. The authors should add to the materials and methods paragraph that the incidence rate was also stratified per year, per age category, per sex.

 

2. Thank you very much for your comments, now we have corrected and improved our article with your precious suggestions.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors,

This manuscript is very well-written. I really enjoyed reading this work, and I would like to congratulate you for introducing this interesting topic. However, I have few minor comments:

1. Introduction: Although the study is specific to Italy, the authors provided some statistics from the US population. It might be helpful to contextualize the introduction and provide some stats from the Italian population (if possible).

2. Methods: I think more details are needed in this section to give more information regarding eligibility criteria (inclusion/exclusion criteria), how many records were accessible, how many were excluded from the analysis and why … etc. Such details may help improve the reproducibility of the study.

3. Also, the authors mentioned in their aims (lines 71-71) that this study aims “to determine the trends of hospitalization, the incidence and the patients’ features of pediatric meniscectomy in Italy.” However, they included only age, gender, length of hospital stay, diagnoses and procedures. It is unclear why the authors did not include other patient features (e.g., cause of injury, the timing of surgery, BMI, …etc.) in their analysis. Justifications for their choice of demographic variables may be needed.

3. The primary diagnosis codes (lines 84-85) are unclear to me. It might be helpful to have a small table defining what all these numbers mean.

4. Results: (line 106): the authors mention “women were prevalent …”. I do not think the word women is appropriate here since the population of interest is children. They might replace it with “female.” The same thing is in (line 128): “men and 1.8 ± 1.2 for women”. The words man/woman are appropriate for adult populations but not children.

5. Also, the figures’ quality could be improved.

6. Discussion: looks ok.

7. Conclusion: To me, the conclusion looks more like results than a straightforward conclusion. Too many numbers are cited in this section which may be (confusing to some extent). I would like to see more plain language (without too many numbers) with direct conclusive points and clear and concise methodological recommendations for future research.

8. Based on the journal's guidelines, the abstract should not exceed 200 words. In this manuscript, however, the abstract is 381 words.

10. The same comment with the references, I think the authors used the Vancouver reference style, but for this journal, references should be in square brackets. For example [1], [1-3] or [1,3].

Thank you,

 

Author Response

 

We would like to thank the reviewers for their helpful comments and their suggestions for improving our manuscript.  We have carefully revised our manuscript accordingly and hope that the changes are acceptable for publication. The changes made are itemized below with our comments to the reviewer’s suggestions. Changes made in the text are highlighted in yellow in the original manuscript as well as reported below.

 

 

Response to Reviewer #2 Comments

 

 

Dear authors,

This manuscript is very well-written. I really enjoyed reading this work, and I would like to congratulate you for introducing this interesting topic. However, I have few minor comments:

 

Thank you very much for your appreciation of our manuscript.

 

1. Introduction:Although the study is specific to Italy, the authors provided some statistics from the US population. It might be helpful to contextualize the introduction and provide some stats from the Italian population (if possible).

 

Thank you very much for your comment: in the introduction section of our study, we adopted epidemiological data from the U.S.A population in order to emphasize the importance of meniscal tears in young and physically active populations and to summarize the most common treatment strategies adopted. Unfortunately, in the current literature that we know of data referring to epidemiology of meniscal tears, treatment choices, patients’ features and postoperative outcomes in the Italian population are missing. This data are also missing for the pediatric population, that is the main focus of our study. For these reasons we introduced the topic by using some statistics from the U.S.A. population. It also remarks the importance of our study that, by means of longitudinal analysis of national registers may help to obtain this missing information: they are crucial in order to adequately understand the burden of pediatric patients with potential orthopaedic sequelae in the adult age, to guide the future operative indications and any associated health assistance plan in Italy. We have now clarified this point in the introduction section

 

2. Methods:I think more details are needed in this section to give more information regarding eligibility criteria (inclusion/exclusion criteria), how many records were accessible, how many were excluded from the analysis and why … etc. Such details may help improve the reproducibility of the study.

 

Thank you very much for your comment. The most important inclusion criterion was the patient’s age: the study refers to the pediatric population (i.e., patients with age between 0 to 14 years). Meniscectomy was defined by the following primary procedures codes: 806 and 80.26. The primary diagnoses codes included were: 717.2, 717.49, 717.0, 717.40, 717.3, 717.5, 717.41, 717.43, 836.1, 717.42, 836.0, 717.1, 717.89 and 717.9.

Diagnoses codes excluded from the present study are listed in the appendix “Excluded ICD codes” and refer to 624 patients that were not included in the study.

 

 

3. Also, the authors mentioned in their aims (lines 71-71) that this study aims “to determine the trends of hospitalization, the incidence and the patients’ features of pediatric meniscectomy in Italy.” However, they included only age, gender, length of hospital stay, diagnoses and procedures. It is unclear why the authors did not include other patient features (e.g., cause of injury, the timing of surgery, BMI, …etc.) in their analysis. Justifications for their choice of demographic variables may be needed.

 

Thank you very much for your comment. As suggested, we have now removed these equivocal sentences from the text. In our analysis we assessed patients for age, gender, length of hospital stay, diagnoses and procedures. Data were obtained from The National Hospital Discharge records (SDO), a database provided by the Italian Ministry of Health. Other patient features (e.g., cause of injury, the timing of surgery, BMI... etc) are not included in our study because they are not provided by The National Hospital Discharge records (SDO) database: in this classification system, in order to guarantee the privacy of personal data, it is not allowed the univocal identification of a patient’s identity.

 

3. The primary diagnosis codes (lines 84-85) are unclear to me. It might be helpful to have a small table defining what all these numbers mean.

 

 

Thank you very much for your comment. As suggested, in Figure 8, we listed main primary diagnoses and in Figure 9 we listed main primary procedures. According to the ICD-9-CM, every diagnosis and procedure corresponds to an univocal code as synthetized below:

 

Main primary diagnoses:

717.2 = Derangement of the posterior horn of medial meniscus;

717.49 = Other derangement of lateral meniscus;

717.0 = Old bucket handle tear of medial meniscus;

717.40 = Derangement of lateral meniscus, unspecified;

717.3 = Derangement of medial meniscus, unspecified;

717.5 = Derangement of meniscus, not elsewhere classified;

717.41 = Bucket handle tear of lateral meniscus;

717.43 = Derangement of the posterior horn of lateral meniscus;

836.1 = Tear of lateral cartilage or meniscus of knee, current;

717.42 = Derangement of the anterior horn of lateral meniscus;

836.0 = Tear of medial cartilage or meniscus of knee, current;

717.1 = Derangement of the anterior horn of medial meniscus;

717.89 = Other internal derangement of knee;

717.9 = Unspecified internal derangement of knee.

 

Main primary procedures:

80.6 = Excision of semilunar cartilage of knee;

80.26 = Arthroscopy, knee;

 

The primary diagnosis and procedure codes of our study refer to The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). It is based on the World Health Organization’s Ninth Revision, International Classification of Diseases (ICD-9). ICD-9-CM is the official system of assigning codes to diagnoses and procedures associated with hospital utilization in the United States. The International Classification of Diseases (ICD) is designed to promote international comparability in the collection, processing, classification, and presentation of mortality statistics.

 

4. Results:(line 106): the authors mention “women were prevalent …”. I do not think the word women is appropriate here since the population of interest is children. They might replace it with “female.” The same thing is in (line 128): “men and 1.8 ± 1.2 for women”. The words man/woman are appropriate for adult populations but not children.

 

Thank you very much for your comments, now we have corrected and improved our article with your precious suggestions.

 

5. Also, the figures’ quality could be improved.

 

Thank you very much for your comment: we have now uploaded figures in PDF format in order to improve figures’quality.

 

6. Discussion:looks ok.

 

Thank you very much for your appreciation of our manuscript.

 

7. Conclusion:To me, the conclusion looks more like results than a straightforward conclusion. Too many numbers are cited in this section which may be (confusing to some extent). I would like to see more plain language (without too many numbers) with direct conclusive points and clear and concise methodological recommendations for future research.

 

Thank you very much for your comments, now we have corrected and improved our article with your precious suggestions.

 

8. Based on the journal's guidelines, the abstract should not exceed 200 words. In this manuscript, however, the abstract is 381 words.

 

Thank you very much for your comments, now we have corrected and improved our article with your precious suggestions.

 

10. The same comment with the references, I think the authors used the Vancouver reference style, but for this journal, references should be in square brackets. For example [1], [1-3] or [1,3].

 

Thank you very much for your comments, now we have corrected and improved our article with your precious suggestions. We have now used the Numbered reference style.