Editor's Comment: On Redundant and Duplicate Articles

The availability of large electronic data bases and our ease in querying them makes recognition of redundant and duplicate publications easier. Both are considered to be a type of self-plagiarism. Once an editor recognizes a publication as redundant or duplicate, he or she may choose to inform

Byung Ihn Choi, president of The Korean Radiologic Society, reported that members of the Ethical Committee on Publication of that group believe our 2 papers belong in the category of redundant publication.
We don't agree with them. It is obvious fact that those 2 papers are entirely different. Let me explain the differences between the first paper (published in KJR) and second paper (published in AJNR).
1) The hypotheses certainly are different. In the first paper, the purpose of the study was to validate the premise that snorers may have a smaller oropharyngeal airway area in relation to increased fat infiltration and an elevated body mass index. Because no statistically significant difference was found between snorers and control subjects in terms of total subcutaneous fat width and total parapharyngeal fat pad thickness, we speculated that the oropharyngeal wall muscles may be the cause of narrowing. Therefore, we planned a new study (second paper, AJNR) with the purpose of seeking dynamic changes of diameters of the airway and the soft tissue components surrounding the airway during the respiratory cycle.
2) The study methods are different; the measurements are entirely different. In the first paper, airway areas, total thicknesses of parapharyngeal fat pad, and subcutaneous fat pad were measured from the section that had the smallest oropharyngeal airway area. In the second paper, on the 2 sections that had the narrowest and widest airway areas, anteroposterior and lateral dimensions of the airway and the thicknesses of left and right parapharyngeal fat pads, left and right pterygoid muscles, and left and right parapharyngeal walls were measured, and mean values were calculated for each section. For each subject, the difference of values in the widest and narrowest phases of the airway were calculated and used for statistical analysis.
3) The results are not similar. These are quite different because the parameters analyzed are also different. The first basic study had been done with the cephalometric measurements in 2002. In the early months of 2003, the values obtained in that study were analyzed initially and the paper was prepared. Subsequently, the first manuscript was submitted to the Auris Nasus Larynx in June 2003. After their negative decision, that paper was submitted to the KJR, with some changes based on reviewer feedback, in November 2003. In that first study, the difference in the smallest oropharyngeal airway area between the snorers and control subjects was significant, while there was no significant difference in the total subcutaneous fat width and total parapharyngeal fat width. (After submitting the paper including those measurements and results to the Auris Nasus Larynx in June 2003, we decided to seek the changes in some soft-tissue components and in some diameters in relation to respiration. Therefore, we planned a new study measuring oropharyngeal diameters [not oropharyngeal area] and pharyngeal walls and changes in these values to understand which parameters might be the cause of snoring.) In the second study, results showed that the lateral pharyngeal walls in snorers were thinner than in control subjects at the largest phase, whereas they become larger at the end of the expirium, the narrowest phase of respiration.
The changes of thickness of the lateral pharyngeal wall between the beginning and the end of expirium in snorers (4.14 mm) were significantly higher than the changes in control subjects (0.66 mm). In that study, changes in the thickness of the lateral pharyngeal wall were significantly related to airway diameter in snorers.
For the second study, we used the CT images obtained from the patients in the first study. We didn't use new study or control groups for 2 reasons. First, to keep out the radiation effects, and second, we thought that if the first study was the basis for the second study, it would be more valuable and reliable.
In conclusion, although the CT scan data obtained from the same patients were used in both papers, we designed the new study (different hypothesis, different measurement parameters, different results, and entirely different discussion) and submitted it to AJNR in No

Editor's Comment: On Redundant and Duplicate Articles
The availability of large electronic data bases and our ease in querying them makes recognition of redundant and duplicate publications easier. Both are considered to be a type of self-plagiarism. Once an editor recognizes a publication as redundant or duplicate, he or she may choose to inform PubMed with or without warning the author(s). This data base immediately will post a retraction note and a warning indicating the nature of this action. Obviously, this process may have deleterious effects on the reputation of the author(s