Accuracy of ICD-9 codes in identifying patients with peptic ulcer and gastrointestinal hemorrhage in the regional healthcare administrative database of Umbria

Massimiliano Orso; Iosief Abraha; Anna Mengoni; Fabrizio Taborchi; Marcello De Giorgi; David Franchini; Paolo Eusebi; Anna Julia Heymann; Alessandro Montedori; Giuseppe Ambrosio; Francesco Cozzolino

doi:10.1371/journal.pone.0235714

Peer Review History

Original SubmissionApril 1, 2020
15 May 2020 Decision Letter - Gianni Virgili, Editor PONE-D-20-09372 Accuracy of ICD-9 codes in identifying patients with peptic ulcer and gastrointestinal hemorrhage in the regional healthcare administrative database of Umbria. PLOS ONE Dear Dr. Abraha, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. The reviewers have provided useful comments to improve the manuscript. We would appreciate receiving your revised manuscript by Jun 29 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: In this study authors carried out a validation study by using the Regional Healthcare administrative database of Umbria. As mentioned in the manuscript authors have published other article aimed to validate cardiovascular and cerebrovascular diseases. The article is well written, understandable and well structured. However, I have some comments that authors should take into account: 1) In the method section, the authors declare that they used ICD9 included in the primary position of the hospital discharge database. I am aware that sometime in second position can be included only a few information, but I was wondering why authors did not include also this codes in the validation (i.e., at least for most important event such as gastric haemorrhage). 2) In the discussion authors declare that other studies have been performed in Italy with the same purpose. Can authors better specify the difference among the other two studies and their one? In addition, can authors specify what their paper adds to the Italian literature on this topic? 3) I partly agree with authors’s sentence “….validation studies of administrative database are context-specific, and thus our results can be applied only to the regional setting of Umbria”. What about the use/adaptation of the same codes in other Italian region? Do authors suppose a different diagnosis procedures/codes used in other Italian regions? If yes, why? Reviewer #2: Dear authors, Your manuscript gives interesting informations on the accuracy of ICD-9 codes in identifying patients with peptic ulcer and gastrointestinal haemorrhage in the regional healthcare administrative database of Umbria and the validated codes will be useful for future epidemiological studies on health services. However, there are certain points that need to be clarified or better discussed: 1) In the "setting and datasource paragraph", no information on medical charts were presented. Please explain the origin of these medical charts. From which hospital did you retrive these data? Is there a data warehouse collecting these informations? 2) Despite the great effort in analysing sensitivity and specificity of ICD-9codes, the authors measure those values only on the percentage of 80 “non cases”. Do you know the “real prevalence” of patients with these diseases in the Umbria region between 2012 and 2014? Is there a pathology registry in Umbria to compare the prevalence of diseases found using administrative data with the “real prevalence” of these diseases in an already validated registry? If these data cannot be recovered (or are inexistent) please discuss in the discussion section. 3) Have you performed any sensitivity analyses considering not only ICD-9 CM codes in the primary position but also using the secondary positions? If not, please discuss further the motivations in using only primary position codes in the limitations of the study. 4) Please define abbreviations upon first appearance in the text. PPV and NPV abbreviation was firstly used in the "statistical analysis” section but the explanation is reported more than once in the “results” section. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. 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Revision 1
28 May 2020 Author Response Reviewer #1: In this study authors carried out a validation study by using the Regional Healthcare administrative database of Umbria. As mentioned in the manuscript authors have published other article aimed to validate cardiovascular and cerebrovascular diseases. The article is well written, understandable and well structured. Thank you for your positive comment. However, I have some comments that authors should take into account: 1) In the method section, the authors declare that they used ICD9 included in the primary position of the hospital discharge database. I am aware that sometime in second position can be included only a few information, but I was wondering why authors did not include also this codes in the validation (i.e., at least for most important event such as gastric haemorrhage). Authors response: We decided to limit our validation study to only consider the codes in primary position because, according to the Italian legislation, the primary diagnosis constitutes the main cause of the need for treatment and/or diagnostic tests, and is mainly responsible for the use of resources. We added this sentence to the study limitations: “We acknowledge that a potential limitation of our study is that we evaluated the accuracy of ICD-9 codes located only in primary position. We chose to limit our analysis only to the codes in primary position because, according to the Italian legislation, the primary diagnosis constitutes the main cause of the need for treatment and/or diagnostic tests, and is mainly responsible for the use of resources”. 2) In the discussion authors declare that other studies have been performed in Italy with the same purpose. Can authors better specify the difference among the other two studies and their one? In addition, can authors specify what their paper adds to the Italian literature on this topic? Authors response: The main difference between our study and the other two Italian studies on this topic is that we were interested in validating the complete ICD-9 codes 531, 532, 534, and 578, while Cattaruzzi et al. and Pisa et al. considered the same ICD-9 codes of our study (peptic ulcer and gastrointestinal hemorrhage), but limited to the sub-codes of hemorrhage or perforation, with the aim to identify patients with upper gastrointestinal bleeding (UGIB) associated with intake of nonsteroidal antiinflammatory drugs (NSAIDs) and other drugs. We decided to perform our study in order to validate for the first time the Regional administrative database of Umbria for these specific codes, that could be used in future to perform other epidemiological studies and health services research. We added this in the discussion section: “The present study is one of the few in Italy and the first in Umbria Region validating the ICD-9 codes related to peptic ulcer and gastrointestinal hemorrhage using clinical charts as a reference standard”. 3) I partly agree with authors’s sentence “….validation studies of administrative database are context-specific, and thus our results can be applied only to the regional setting of Umbria”. What about the use/adaptation of the same codes in other Italian region? Do authors suppose a different diagnosis procedures/codes used in other Italian regions? If yes, why? Authors response: In general, results that originate from a healthcare database are immediately applicable only to the setting in which such database has been validated, due to differences that may exist with respect to demographics, disease prevalence, and standards of care, among different regions. However, we think that our methodology could be replicated in other settings in order to identify possible differences in diagnostic accuracy results. We amended the text as follows: “Regarding the generalizability of our study, we want to highlight that, in general, validation studies of administrative databases are context-specific due to differences that may exist in demographics, disease prevalence, and standards of care among different contexts, and thus our results can confidently be applied only to the regional setting of Umbria”. Reviewer #2: Dear authors, Your manuscript gives interesting informations on the accuracy of ICD-9 codes in identifying patients with peptic ulcer and gastrointestinal haemorrhage in the regional healthcare administrative database of Umbria and the validated codes will be useful for future epidemiological studies on health services. Thank you for your positive comment. However, there are certain points that need to be clarified or better discussed: 1) In the "setting and datasource paragraph", no information on medical charts were presented. Please explain the origin of these medical charts. From which hospital did you retrive these data? Is there a data warehouse collecting these informations? Authors response: We added in the text the description of the hospitals where the clinical charts came from: “We considered all the residents in the Umbria Region > 18 years discharged from seven hospitals (Perugia, Terni, Foligno, Città di Castello, Orvieto, Gubbio-Gualdo Tadino, Spoleto) between 2012 and 2014 with a diagnosis of peptic ulcer or gastrointestinal haemorrhage”. We presented a minimal anonymized dataset containing the main characteristics of the study sample (see Supplementary material). 2) Despite the great effort in analysing sensitivity and specificity of ICD-9codes, the authors measure those values only on the percentage of 80 “non cases”. Do you know the “real prevalence” of patients with these diseases in the Umbria region between 2012 and 2014? Is there a pathology registry in Umbria to compare the prevalence of diseases found using administrative data with the “real prevalence” of these diseases in an already validated registry? If these data cannot be recovered (or are inexistent) please discuss in the discussion section. Authors response: Unfortunately, in Umbria there is not a pathology registry for ulcers or gastrointestinal hemorrhage, and therefore we do not know the real prevalence of the diseases. We based our estimation of sensitivity and specificity using a sample of “non-cases”, i.e. patients who had been discharged in the same period in a gastroenterology ward with a diagnosis other than peptic ulcer or gastrointestinal hemorrhage, from which we extracted a random sample of 80 patients. We added in the discussion section the following sentence: “Instead, in order to estimate sensitivity and specificity, in absence of a disease registry for peptic ulcers and gastrointestinal hemorrhage that constitutes the real prevalence of the diseases, we chose to consider a sample of “non-cases”, i.e. patients who had been discharged in the same period in a gastroenterology ward with a diagnosis other than peptic ulcer or gastrointestinal hemorrhage, to individuate possible false negatives”. 3) Have you performed any sensitivity analyses considering not only ICD-9 CM codes in the primary position but also using the secondary positions? If not, please discuss further the motivations in using only primary position codes in the limitations of the study. Authors response: We did not perform a sensitivity analysis considering the codes in secondary position because all our study sample was discharged with a diagnosis code in primary position (we did not extracted patients with the codes in secondary positions). We explained in the limitations the reasons why we chose to focus on the codes in primary position, adding the following sentence: “We chose to limit our analysis only to the codes in primary position because, according to the Italian legislation, the primary diagnosis constitutes the main cause of the need for treatment and/or diagnostic tests, and is mainly responsible for the use of resources”. 4) Please define abbreviations upon first appearance in the text. PPV and NPV abbreviation was firstly used in the "statistical analysis” section but the explanation is reported more than once in the “results” section. Authors response: Thank you for your suggestion. We amended the text accordingly. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0235714.r002
22 Jun 2020 Decision Letter - Gianni Virgili, Editor Accuracy of ICD-9 codes in identifying patients with peptic ulcer and gastrointestinal hemorrhage in the regional healthcare administrative database of Umbria. PONE-D-20-09372R1 Dear Dr. Abraha, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Gianni Virgili Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0235714.r003
Formally Accepted
24 Jun 2020 Acceptance Letter - Gianni Virgili, Editor PONE-D-20-09372R1 Accuracy of ICD-9 codes in identifying patients with peptic ulcer and gastrointestinal hemorrhage in the regional healthcare administrative database of Umbria. Dear Dr. Abraha: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Gianni Virgili Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0235714.r004

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