Skip to main content
Download PDF

Using Kano diagrams to display the most cited article types, affiliated countries, authors and MeSH terms on spinal surgery in recent 12 years

European Journal of Medical Research volume 26, Article number: 22 (2021) Cite this article

Abstract

Background

Citation analysis has been increasingly applied to assess the quantity and quality of scientific research in various fields worldwide. However, these analyses on spinal surgery do not provide visualization of results. This study aims (1) to evaluate the worldwide research citations and publications on spinal surgery and (2) to provide visual representations using Kano diagrams onto the research analysis for spinal surgeons and researchers.

Methods

Article abstracts published between 2007 and 2018 were downloaded from PubMed Central (PMC) in 5 journals, including Spine, European Spine Journal, The Spine Journal, Journal of Neurosurgery: Spine, and Journal of Spinal Disorders and Techniques. The article types, affiliated countries, authors, and Medical subject headings (MeSH terms) were analyzed by the number of article citations using x-index. Choropleth maps and Kano diagrams were applied to present these results. The trends of MeSH terms over the years were plotted and analyzed.

Results

A total of 18,808 publications were extracted from the PMC database, and 17,245 were affiliated to countries/areas. The 12-year impact factor for the five spine journals is 5.758. We observed that (1) the largest number of articles on spinal surgery was from North America (6417, 37.21%). Spine earns the highest x-index (= 82.96). Comparative Study has the highest x-index (= 66.74) among all article types. (2) The United States performed exceptionally in x-indexes (= 56.86 and 44.5) on both analyses done on the total 18,808 and the top 100 most cited articles, respectively. The most influential author whose x-index reaches 15.11 was Simon Dagenais from the US. (3) The most cited MeSH term with an x-index of 23.05 was surgery based on the top 100 most cited articles. The most cited article (PMID = 18164449) was written by Dagenais and his colleagues in 2008. The most productive author was Michael G. Fehlings, whose x-index and the author's impact factor are 13.57(= √(13.16*14)) and 9.86(= 331.57/33.64), respectively.

Conclusions

There was a rapidly increasing scientific productivity in the field of spinal surgery in the past 12 years. The US has extraordinary contributions to the publications. Furthermore, China and Japan have increasing numbers of publications on spinal surgery. This study with Kano diagrams provides an insight into the research for spinal surgeons and researchers.

Background

The number of publications on spinal surgery has dramatically increased in recent years [1,2,3]. The citation analysis has been applied to measure individual research achievements (IRA) [4,5,6,7,8,9]. However, several changes have been encountered in those studies using bibliometric analyses, such as all factors (e.g., authors or affiliated countries/areas) in an article are viewed with equal contribution to an article. As such, the research achievements might be unfair and biased in IRA measurement. Two major difficulties we encountered in our study include the following: (1) coauthors with equal credits in an article byline are unreasonable; and (2) the Hirsch’s h-index [7] has less discrimination power due to its integer nature (i.e., many of the same index value) making it difficult to differentiate the personal IRA [10].

The total citation count (e.g., author impact factor, AIF = citations/publications for each author) [4, 5]) has the disadvantage of favoring researchers with few highly cited top publications or productive authors with many publications, but a relatively small number of citations [4, 5].

While the h-index is determined by the maximum square that fits under the citation curve of an author when plotting the number of citations in decreasing order, the x-index [= \(\sqrt {\mathop {\max }\limits_{i} (i \times c_{i} )}\), where all the number of citations (denoted by ci) in the x core at publication [9] was proposed in 2018 and determined by the maximum rectangular area that fits under the curve. The disadvantage of the x-index is the equal importance placed on the citations and publications, regardless of the IRA tendency toward the citations or the publications. The Kano diagram [11] is thus suitable for interpreting the feature for factors in three parts: the excitement, the performance, and the basic requirement denoting the IRAs as the influential, the prolific, and the productive, respectively, in the previous articles [12, 13].

Although many studies [14,15,16,17,18,19,20,21] have used bibliometric methods for evaluating worldwide research productivity in many biomedical fields, including those published in general orthopedics and its subspecialties [22,23,24], bibliometric analyses on the quantity and quality of articles published in spine journals worldwide are still rare [2]. Only three [1,2,3] were found searching keyword (spine surgery [Title]) AND bibliometric [MeSH Major Topic] on PubMed Central (PMC) as of November 11, 2019, but all of them lack substantial visualizations in results.

Therefore, the purpose of this study was (1) to evaluate the research citations and publications in major spine journals using the PMC database in recent 12 years and (2) to provide visual representations using the visual Kano diagrams onto the spinal research to display IRAs for surgeons and researchers.

Materials and methods

Data source

We searched the PMC using “(((((((((1529–9430) OR 0940–6719) OR 1432–0932) OR 0362–2436) OR 1528–1159) OR 1547–5654) OR 1547–5646) OR 1536–0652) OR 1539–2465) AND ("2007"[Date—Publication]: "2018"[Date—Publication])” on November 2, 2019, for retrieving publications in five relevant journals, including Spine, European Spine Journal, The Spine Journal, Journal of Neurosurgery: Spine, and Journal of Spinal Disorders and Techniques. In total, we downloaded 18,808 abstracts that were published from 2007 to 2018, see Additional file 1.

All data used in this study were downloaded from the PMC, meaning that the study did not require ethical approval according to the regulations promulgated by the Taiwan Ministry of Health and Welfare.

Two prerequisites used for evaluating author IRAs

An author-weighted scheme (AWS) was applied to determine coauthors’ contributions in article bylines [25] to improve the unreasonable phenomenon that all papers are equal weight irrespective of the number of coauthors [26, 27]. Accordingly, more importance was given to the first (primary) authors and the last (corresponding/supervisory) authors, while we assumed that the others (i.e., the middle authors) made smaller contributions [25].

Furthermore, the x-index [9] used in this study generalizes the h-index [7], which is determined by the square area (i.e., the number of publications equal to the citation point). The x-index thus surpasses the h-index in differentiating the personal IRA among affiliated countries/areas, authors, or the medical subject headings (MeSH terms) [28].

Task 1: x-index for journals and article types

The trend of the number of articles across continents worldwide and journals over time was shown in a contingency table based on the 1st authors affiliated to their countries/areas. Journals and article types were compared to identify the most influential ones with either a higher x-index or h-index.

Task 2: x-index for affiliated countries/areas and authors

Three plots of the choropleth map [29], the bar chart, and the Kano model [11] were applied to display IRA features for affiliated countries/areas and authors based on the 18,808 abstracts and the top 100 most cited articles, respectively.

Task 3: x-index for MeSH terms

MeSH terms extracted from the top 100 most cited articles were represented by the topic burst on the topic of spine surgery [30]. Three plots of the Kano diagram, the line chart, and the clusters using social network analysis(SNA) [31] were used for interpreting (1) the evolution of topics in the past 12 years, (2) the most cited terms, and (3) the MeSH clusters are separated by the SNA using Pajek software [32].

The most cited article and the most productive authors in these 18,808 abstracts were extracted separately from the analysis performed on an author-made routine with codes of visual basic for application(VBA) on Microsoft Excel.

Results

x-Index for journals and article types

A total of 18,808 publications were extracted, of those 17,245 were identified with affiliated countries/areas, and 46,795 authors were included. The 12-year impact factor for the five journals together is 5.758. The largest number of articles on spinal surgery was from North America (6417, 37.21%); see Table 1. The journal Spine earns the highest x-index (= 82.96); see Table 2. Comparative study has the highest x-index (= 66.74) among article types; see Table 3.

Table 1 Publications across continents and journals over the years based on 1st authors
Full size table
Table 2 Comparison of SCI IF and PubMed IF for journals
Full size table
Table 3 Bibliometrics on article types
Full size table

x-Index for affiliated countries/areas and authors

The United States has the highest x-indexes (= 56.86 and 44.5) among the world based on the total 18,808 publications and the top 100 most cited articles, respectively; see Fig. 1. The most influential author with the x-index = 15.11 is Simon Dagenais from the US; see Fig. 2. We can see the difference in choropleth maps in Figs. 1 and 2, indicating only four countries: the US, Netherlands, Canada, and Finland play an influential role on the topic based on the top 100 most cited articles. Interested readers are invited to scan the QR-code and click the country of interest to view the x-index and other details on the information of the entity.

Fig. 1
figure 1

Research achievements for countries on spine using x-index and 18,808 publications

Full size image
Fig. 2
figure 2

Research achievements for authors on spine using x-index and top 100 cited articles

Full size image

x-Index for MeSH terms

A total of 82 MeSH terms were retrieved from the top 100 most cited articles. The most cited MeSH term was surgery with the x-index = 23.05. We can see the term of surgery with a red bubble on the right-bottom corner in the Kano diagram (top in Fig. 3), indicating the tendency toward its productive feature (i.e., with more weights on publications according to the definition of x-index).

Fig. 3
figure 3

Metrics for the top MeSH terms on spine across the years using x-index to display

Full size image

The principal MeSH terms extracted from the top panel in Fig. 3 are present at the middle panel of Fig. 3, which shows that both costs of illness and disability evaluation occupy a lower proportion over the years. Both epidemiology and diagnostic imaging have accounted for more since 2016, implying the importance of these topics in spinal surgery in recent years. In contrast, the MeSH term of surgery has been dramatically decreasing since 2016, indicating a relatively smaller number of publications was on the topic of surgery.

The most cited article (PMID = 18,164,449) was written by Dagenais and his colleagues in 2008 [33]. The most productive author is Michael G. Fehlings, with an x-index = 13.57 (= √(13.16*14)) and the AIF = 9.86 (= 331.57/33.64 = the cited/the citable computed by the AWS mentioned in Methods 2,2). Interested readers are invited to search the term of (Fehlings, Michael G. [Author—Full]) AND surgery[MeSH Major Topic] to view his publications on PMC.

Discussion

We observed that the largest number of articles on spinal surgery was from North America (6417, 37.21%) and Asia (5812, 33.7%). The results are different from the findings that the US and Europe are more dominant in science [34, 35].

In the previous study [2], the largest number of publications in the field of spinal surgery was from the US (5137; 39.17%), followed by Japan (1408; 10.74%), and China (1131; 8.62%). The US had the highest h-index (106), followed by Canada (60), and the United Kingdom (54). However, our study observed a different result where the most productive countries are the US (5745, 32.95%), followed by China (1770,10.15%), and Japan (1712, 9.82%). The US also had the highest x-index (56.86), followed by China (39.06), and Japan (32.31); see the bottom panel in Fig. 1.

Furthermore, Spine earns the highest x-index(= 82.96) of all journals, and comparative study has an x-index (= 66.74) highest among article types. We have not seen any publication that applied x-index in bibliometric analyses to measure IRAs on spinal surgery in literature [1,2,3, 14,15,16,17,18,19,20,21,22,23,24]. The x-index [9] generalizes the h-index [7], which is determined by the square area. The drawback of the x-index is the equal importance placed on the citations and publications that can be resolved by using the Kano diagram; see Figs. 1, 2, 3, which is a highlight of this study.

The second feature of this study is the AWS used for quantifying the contributions of authors (or their affiliated countries) in an article byline. A fair IRAs could not be achieved; otherwise, see Figs. 1 and 2. Similarly, the weights of MeSH terms can be quantified by the AWS with an equal size (e.g., Wi = citations/n, where n = the number of MeSH terms in an article and Wi is the weight of a MeSH term(i)) in an article and then plotted in Fig. 3.

Another feature is about the choropleth map incorporated in the bar chart and the Kano diagram as map legends designed for visualizing the metric disparities for better interpretation of values on the choropleth map [36]. For instance, the US with a yellow bubble is the most influential country in the performance area on the bottom panel in Fig. 1, providing a complemental interpretation of the choropleth map at the top panel in Fig. 1. All figures provide QR-codes for interested readers to examine the details on the information with the dashboard on Google Maps, different from those regarding spine-related studies [37, 38] using the world map only available in color online.

We present the most cited MeSH term of surgery with the x-index = 23.05 based on the top 100 most cited articles. The method computing IRA for MeSH terms has never been seen before in academics although the placement scheme is similar to the coauthors suitable for quantifying their credits with the AWS in an article.

There are several limitations to this study. First, the five main journals relevant to spinal surgery in this study cannot represent other specialties and the many more basic research journals publishing articles related to spinal surgery. Nevertheless, these five major journals used in this study can represent the study and research contributed to the field.

Second, there might be some biases in author identification because some authors in the bibliometric database may have the same name or use the same abbreviations, but are affiliated to different institutions.

Third, the data extracted from the PMC cannot be generalized to other major citation databases such as the Scientific Citation Index (SCI; Thomson Reuters, New York, NY, the United States) and Scopus (Elsevier, Amsterdam, the Netherlands).

Lastly, many researchers believe that the impact factor or citation does not reflect the scientific quality of the research [39,40,41]. Many journals are now preferring citation distribution curve over the JIF [39]. It is worth discussing how this method for author and journal analyses can be included. Whether the x-index[9] that is applied in this study can be used for defining research achievements in a wider range of disciplines is worthy of further studies and discussions in the future (Fig. 4).

Fig. 4
figure 4

The most cited research institutes using x-index to display

Full size image

Conclusions

There was a rapid increase in scientific research productivity in the field of spinal surgery in the past 12 years. The US has exceptional contributions to publications. China and Japan have increasing contributions to the field. This study with the visualization by the Kano diagrams provides an insight into the value of research for spinal surgeons and researchers.

Availability of data and materials

All data used in this study are available in Additional file files.

Abbreviations

AWS:

Author-weighted scheme

MeSH:

Medical subject headings

PMC:

Pubmed Center

SCI:

Scientific Citation Index

SNA:

Social network analysis

References

  1. Fan G, Han R, Zhang H, He S, Chen Z. Worldwide research productivity in the field of minimally invasive spine surgery: a 20-year survey of publication activities. Spine (Phila Pa 1976). 2017;42(22):1717–22.

    Article  Google Scholar 

  2. Wei M, Wang W, Zhuang Y. Worldwide research productivity in the field of spine surgery: a 10-year bibliometric analysis. Eur Spine J. 2016;25(4):976–82.

    Article  Google Scholar 

  3. Virk SS, Yu E. The top 50 articles on minimally invasive spine surgery. Spine (Phila Pa 1976). 2017;42(7):513–9.

    Article  Google Scholar 

  4. Lippi G, Mattiuzzi C. Scientist impact factor (SIF): a new metric for improving scientists’ evaluation? Ann Transl Med. 2017;5(15):303.

    Article  Google Scholar 

  5. Pan RK, Fortunato S. Author impact factor: tracking the dynamics of individual scientific impact. Sci Rep. 2014;4:4880.

    Article  CAS  Google Scholar 

  6. Chien TW, Wang HY, Kan WC, Su SB. Whether article types of a scholarly journal are different in cited metrics using cluster analysis of MeSH terms to display: a bibliometric analysis. Medicine (Baltimore). 2019;98(43):e17631.

    Article  Google Scholar 

  7. Hirsch JE. An index to quantify an individual’s scientific research output. Proc Natl Acad Sci USA. 2005;102:16569–72.

    Article  CAS  Google Scholar 

  8. Egghe L. Theory and practise of the g-index. Scientometrics. 2006;69:131–52.

    Article  Google Scholar 

  9. Fenner T, Harris M, Levene M, Bar-Ilan J. A novel bibliometric index with a simple geometric interpretation. PLoS ONE. 2018;13(7):e0200098.

    Article  Google Scholar 

  10. Huang MH, Chi PS. A comparative analysis of the application of H-index, G-index, and A-index in institutional-level research evaluation. J Libr Inf Stud. 2010;8(2):1–10.

    Google Scholar 

  11. Kano N, Seraku N, Takahashi F, Tsuji S. Attractive quality and must-be quality. J Jpn Soc Quality Control. 1984;41:39–48.

    Google Scholar 

  12. Zhang CT. The e-index, complementing the h-index for excess citations. The e-index, complementing the h-index for excess citations. PLoS ONE. 2009;4(5):e5429.

    Article  Google Scholar 

  13. Zhang CT. The h’-index, effectively improving the h-index based on the citation distribution. PLoS ONE. 2013;8(4):e59912.

    Article  CAS  Google Scholar 

  14. Zyoud SH, Al-Jabi SW, Sweileh WM. Worldwide research productivity in the field of electronic cigarette: a bibliometric analysis. BMC Public Health. 2014;14:667.

    Article  Google Scholar 

  15. Michalopoulos A, Falagas ME. A bibliometric analysis of global research production in respiratory medicine. Chest. 2005;128(6):3993–8.

    Article  Google Scholar 

  16. Hauptman JS, Chow DS, Martin NA, Itagaki MW. Research productivity in neurosurgery: trends in globalization, scientific focus, and funding. J Neurosurg. 2011;115(6):1262–72.

    Article  Google Scholar 

  17. Cheng T, Zhang G. Worldwide research productivity in the field of rheumatology from 1996 to 2010: a bibliometric analysis. Rheumatol (Oxford). 2013;52(9):1630–4.

    Article  Google Scholar 

  18. Zyoud SH, Al-Jabi SW, Sweileh WM. Worldwide research productivity of paracetamol (acetaminophen) poisoning: a bibliometric analysis (2003–2012). Hum Exp Toxicol. 2014;34(1):12–23.

    Article  Google Scholar 

  19. Thornton K, Lee DJ, Yuan JC, Knoernschild KL, Campbell SD, Sukotjo C. An analysis of prosthodontic research productivity: geographic, economic, and collaborative perspective. J Prosthodont. 2012;21(1):73–8.

    Article  Google Scholar 

  20. Chen HL, Cai DY, Shen WQ, Liu P. Bibliometric analysis of pressure ulcer research: 1990–2009. J Wound Ostomy Continence Nurs. 2010;37(6):627–32.

    Article  Google Scholar 

  21. Jamshidi AR, Gharibdoost F, Nadji A, Nikou M, Habibi G, Mardani A, Ghaemi M. Presentation of psoriatic arthritis in the literature: a twenty-year bibliometric evaluation. Rheumatol Int. 2013;33(2):361–7.

    Article  Google Scholar 

  22. Hui Z, Yi Z, Peng J. Bibliometric analysis of the orthopedic literature. Orthopedics. 2013;36(10):e1225–32.

    Article  Google Scholar 

  23. Fernandes CH, Meirelles LM, Raduan Neto J, dos Santos JB, Faloppa F, Albertoni WM. Characteristics of global publications about wrist arthroscopy: a bibliometric analysis. Hand Surg. 2012;17(3):311–5.

    Article  Google Scholar 

  24. Mao Z, Wang G, Mei X, Chen S, Liu X, Zeng X, Long A, Zhang L, Tang P. Systematic reviews on reports of hip fractures in Web of Science: a bibliometric analysis of publication activity. Chin Med J (Engl). 2014;127(13):2518–22.

    Google Scholar 

  25. Chien TW, Chow JC, Chang Y, Chou W. Applying Gini coefficient to evaluate the author research domains associated with the ordering of author names: a bibliometric study. Medicine (Baltimore). 2018;97(39):e12418.

    Article  Google Scholar 

  26. Sekercioglu CH. Quantifying coauthor contributions. Science. 2008;322(5900):371.

    Article  CAS  Google Scholar 

  27. Vavryčuk V. Fair ranking of researchers and research teams. PLoS ONE. 2018;13(4):e0195509.

    Article  Google Scholar 

  28. Balogh SG, Zagyva D, Pollner P, Palla G. Time evolution of the hierarchical networks between PubMed MeSH terms. PLoS ONE. 2019;14(8):e0220648.

    Article  CAS  Google Scholar 

  29. Chien TW, Wang HY, Hsu CF, Kuo SC. Choropleth map legend design for visualizing the most influential areas in article citation disparities: a bibliometric study. Medicine (Baltimore). 2019;98(41):e17527.

    Article  Google Scholar 

  30. Shen L, Xiong B, Li W, Lan F, Evans R, Zhang W. Visualizing collaboration characteristics and topic burst on international mobile health research: bibliometric analysis. JMIR Mhealth Uhealth. 2018;6(6):e135.

    Article  Google Scholar 

  31. Chien TW, Chang Y, Wang HY. Understanding the productive author who published papers in medicine using National Health Insurance Database: a systematic review and meta-analysis. Medicine (Baltimore). 2018;97(8):e9967.

    Article  Google Scholar 

  32. Batagelj V, Mrvar A. Pajek—analysis, and visualization of large networks. In: Jünger M, Mutzel P, editors. Graph drawing software. Berlin: Springer; 2003. p. 77–103.

    Google Scholar 

  33. Dagenais S, Caro J, Haldeman S. A systematic review of low back pain cost of illness studies in the United States and internationally. Spine J. 2008;8(1):8–20.

    Article  Google Scholar 

  34. Leydesdorff L, Wagner C, Park HW, Adams J. International collaboration in science: the global map and the network. CoRR abs/1301.0801 (2013)

  35. Glänzel W, Schlemmer B. National research profiles in a changing Europe (1983–2003): an exploratory study of sectoral characteristics in the Triple Helix. Scientometrics. 2007;70(2):267–75.

    Article  Google Scholar 

  36. Cromley RG, Ye Y. Ogive-based legends for choropleth mapping. Cartogr Geogr Inform Sci. 2006;33:257–68. https://doi.org/10.1559/152304006779500650.

    Article  Google Scholar 

  37. Ding F, Jia Z, Liu M. National representation in the spine literature: a bibliometric analysis of highly cited spine journals. Eur Spine J. 2016;25(3):850–5.

    Article  Google Scholar 

  38. Chen YC, Kuo CH, Cheng CM, Wu JC. Recent advances in the management of cervical spondylotic myelopathy: bibliometric analysis and surgical perspectives. J Neurosurg Spine. 2019;31(3):299–309.

    Article  Google Scholar 

  39. Callaway E. Beat it, impact factor! Publishing elite turns against controversial metric. 2019. https://www.nature.com/news/polopoly_fs/1.20224!/menu/main/topColumns/topLeftColumn/pdf/nature.2016.20224.pdf. 11 Oct 2019.

  40. Journal Editorial. 2016. Time to remodel the journal impact factor. Nature. 535(7613):466. https://www.nature.com/articles/535466a

  41. Seglen PO. Why the impact factor of journals should not be used for evaluating research. BMJ. 1997;314(7079):498–502.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank Enago (www.enago.tw) for the English language review of this manuscript.

Funding

There are no sources of funding to be declared.

Author information

Authors and Affiliations

  1. Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan

    Po-Hsin Chou

  2. School of Medicine, National Yang-Ming University, Taipei, Taiwan

    Po-Hsin Chou

  3. Medical School, St. George’s, University of London, London, UK

    Yu-Tsen Yeh

  4. Department of Nephrology, Chi-Mei Medical Center, Tainan, Taiwan

    Wei-Chih Kan

  5. Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan

    Tsair-Wei Chien

  6. Department of Optometry, Chung Hwa University of Medical Technology, Jen-Teh, Tainan, Taiwan

    Shu-Chun Kuo

  7. Department of Ophthalmology, Chi-Mei Medical Center, 901 Chung Hwa Road, Yung Kung, Yong Kang, Tainan, Taiwan

    Shu-Chun Kuo

Authors
  1. Po-Hsin Chou
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yu-Tsen Yeh
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Wei-Chih Kan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Tsair-Wei Chien
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Shu-Chun Kuo
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

PH developed the study concept and design. TWC, WC and SC analyzed and interpreted the data. YT monitored the process of this study and helped in responding to the reviewers’ advice and comments. TWC drafted the manuscript, and all authors provided critical revisions for important intellectual content. The study was supervised by SC. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Shu-Chun Kuo.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Additional file

1: Dataset used in this study.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chou, PH., Yeh, YT., Kan, WC. et al. Using Kano diagrams to display the most cited article types, affiliated countries, authors and MeSH terms on spinal surgery in recent 12 years. Eur J Med Res 26, 22 (2021). https://doi.org/10.1186/s40001-021-00494-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s40001-021-00494-x

Keywords

European Journal of Medical Research

ISSN: 2047-783X

Contact us