Clifford Y. Ko

49.4k total citations · 17 hit papers
533 papers, 36.8k citations indexed

About

Clifford Y. Ko is a scholar working on Surgery, Cardiology and Cardiovascular Medicine and Oncology. According to data from OpenAlex, Clifford Y. Ko has authored 533 papers receiving a total of 36.8k indexed citations (citations by other indexed papers that have themselves been cited), including 274 papers in Surgery, 223 papers in Cardiology and Cardiovascular Medicine and 162 papers in Oncology. Recurrent topics in Clifford Y. Ko's work include Cardiac, Anesthesia and Surgical Outcomes (217 papers), Colorectal Cancer Surgical Treatments (82 papers) and Colorectal Cancer Screening and Detection (57 papers). Clifford Y. Ko is often cited by papers focused on Cardiac, Anesthesia and Surgical Outcomes (217 papers), Colorectal Cancer Surgical Treatments (82 papers) and Colorectal Cancer Screening and Detection (57 papers). Clifford Y. Ko collaborates with scholars based in United States, Canada and United Kingdom. Clifford Y. Ko's co-authors include Karl Y. Bilimoria, Bruce L. Hall, Melinda A. Maggard, Mark E. Cohen, Andrew K. Stewart, David P. Winchester, David S. Zingmond, Karen Richards, Ryan P. Merkow and David J. Bentrem and has published in prestigious journals such as New England Journal of Medicine, JAMA and Journal of Clinical Oncology.

In The Last Decade

Clifford Y. Ko

510 papers receiving 35.9k citations

Hit Papers

The National Cancer Data Base: A Powerful Initiative to I... 2003 2026 2010 2018 2008 2013 2004 2009 2003 500 1000 1.5k
What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

  1. The National Cancer Data Base: A Powerful Initiative to Improve Cancer Care in the United States
    2008 1.6k citations Karl Y. Bilimoria, Andrew K. Stewart et al. Annals of Surgical Oncology profile →
  2. Development and Evaluation of the Universal ACS NSQIP Surgical Risk Calculator: A Decision Aid and Informed Consent Tool for Patients and Surgeons
    2013 1.3k citations Karl Y. Bilimoria, Clifford Y. Ko et al. Journal of the American College of Surgeons profile →
  3. Colon Cancer Survival Rates With the New American Joint Committee on Cancer Sixth Edition Staging
    2004 1.3k citations Clifford Y. Ko et al. profile →
  4. Toward Robust Information: Data Quality and Inter-Rater Reliability in the American College of Surgeons National Surgical Quality Improvement Program
    2009 1.2k citations Karen Richards, Clifford Y. Ko et al. Journal of the American College of Surgeons profile →
  5. The Aging Population and Its Impact on the Surgery Workforce
    2003 664 citations David A. Etzioni, Clifford Y. Ko et al. Annals of Surgery profile →
  6. American College of Surgeons and Surgical Infection Society: Surgical Site Infection Guidelines, 2016 Update
    2016 651 citations Kristen A. Ban, Joseph P. Minei et al. Journal of the American College of Surgeons profile →
  7. Does Surgical Quality Improve in the American College of Surgeons National Surgical Quality Improvement Program
    2009 625 citations Bruce L. Hall, Barton H. Hamilton et al. Annals of Surgery profile →
  8. Underlying Reasons Associated With Hospital Readmission Following Surgery in the United States
    2015 588 citations Ryan P. Merkow, Bruce L. Hall et al. profile →
  9. Optimal Preoperative Assessment of the Geriatric Surgical Patient: A Best Practices Guideline from the American College of Surgeons National Surgical Quality Improvement Program and the American Geriatrics Society
    2012 574 citations Ryan P. Merkow, Clifford Y. Ko et al. Journal of the American College of Surgeons profile →
  10. Extent of Surgery Affects Survival for Papillary Thyroid Cancer
    2007 487 citations Karl Y. Bilimoria, David J. Bentrem et al. Annals of Surgery profile →
  11. First Report from the American College of Surgeons Bariatric Surgery Center Network
    2011 481 citations Matthew M. Hutter, Clifford Y. Ko et al. Annals of Surgery profile →
  12. Quality Improvement in Surgery: the American College of Surgeons National Surgical Quality Improvement Program Approach
    2010 452 citations Angela M. Ingraham, Karen Richards et al. profile →
  13. Optimizing ACS NSQIP Modeling for Evaluation of Surgical Quality and Risk: Patient Risk Adjustment, Procedure Mix Adjustment, Shrinkage Adjustment, and Surgical Focus
    2013 446 citations Mark E. Cohen, Clifford Y. Ko et al. Journal of the American College of Surgeons profile →
  14. Small Bowel Cancer in the United States
    2008 442 citations Karl Y. Bilimoria, David J. Bentrem et al. Annals of Surgery profile →
  15. Preoperative Predictors of Weight Loss Following Bariatric Surgery: Systematic Review
    2011 426 citations Masha J. Livhits, Clifford Y. Ko et al. profile →
  16. Optimal Perioperative Management of the Geriatric Patient: A Best Practices Guideline from the American College of Surgeons NSQIP and the American Geriatrics Society
    2016 367 citations Clifford Y. Ko et al. Journal of the American College of Surgeons profile →
  17. National Cluster-Randomized Trial of Duty-Hour Flexibility in Surgical Training
    2016 279 citations Karl Y. Bilimoria, Mark E. Cohen et al. profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Clifford Y. Ko United States 98 20.0k 12.1k 9.3k 7.2k 3.7k 533 36.8k
John D. Birkmeyer United States 92 17.4k 0.9× 8.3k 0.7× 9.1k 1.0× 9.4k 1.3× 3.0k 0.8× 253 32.5k
C. Ronald MacKenzie United States 23 10.7k 0.5× 5.8k 0.5× 6.6k 0.7× 7.1k 1.0× 8.3k 2.3× 57 42.3k
Karl Y. Bilimoria United States 69 9.6k 0.5× 7.0k 0.6× 4.3k 0.5× 4.4k 0.6× 2.2k 0.6× 413 20.3k
William G. Henderson United States 92 16.2k 0.8× 3.3k 0.3× 15.1k 1.6× 7.6k 1.1× 3.5k 1.0× 409 35.4k
Gary H. Lyman United States 104 7.7k 0.4× 24.9k 2.1× 6.1k 0.7× 6.3k 0.9× 4.5k 1.2× 602 48.3k
Justin B. Dimick United States 83 13.1k 0.7× 4.2k 0.3× 8.3k 0.9× 6.1k 0.8× 2.1k 0.6× 501 26.0k
Shukri F. Khuri United States 75 11.2k 0.6× 2.6k 0.2× 9.0k 1.0× 5.0k 0.7× 1.4k 0.4× 221 20.8k
H. Gilbert Welch United States 66 7.5k 0.4× 7.6k 0.6× 1.7k 0.2× 5.9k 0.8× 2.2k 0.6× 176 24.3k
Catherine M. Tangen United States 57 6.7k 0.3× 5.1k 0.4× 2.8k 0.3× 14.5k 2.0× 2.0k 0.5× 254 38.7k
Lars Pedersen Denmark 69 5.8k 0.3× 2.6k 0.2× 4.3k 0.5× 3.3k 0.5× 3.6k 1.0× 353 22.8k

Countries citing papers authored by Clifford Y. Ko

Since Specialization
Citations

This map shows the geographic impact of Clifford Y. Ko's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Clifford Y. Ko with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Clifford Y. Ko more than expected).

Fields of papers citing papers by Clifford Y. Ko

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Clifford Y. Ko. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Clifford Y. Ko. The network helps show where Clifford Y. Ko may publish in the future.

Co-authorship network of co-authors of Clifford Y. Ko

This figure shows the co-authorship network connecting the top 25 collaborators of Clifford Y. Ko. A scholar is included among the top collaborators of Clifford Y. Ko based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Clifford Y. Ko. Clifford Y. Ko is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
2.
Palis, Bryan E., et al.. (2024). Social Vulnerability and Receipt of Guideline-Concordant Care among Patients with Colorectal Cancer. Journal of the American College of Surgeons. 240(2). 167–178. 2 indexed citations
3.
Cram, Peter, Mark E. Cohen, Clifford Y. Ko, et al.. (2022). Surgical Outcomes in Canada and the United States: An Analysis of the ACS‐NSQIP Clinical Registry. World Journal of Surgery. 46(5). 1039–1050. 5 indexed citations
4.
Kalogera, Eleftheria, Gregg Nelson, Jessica Liu, et al.. (2019). Surgical Technical Evidence Review for Gynecologic Surgery Conducted for the Agency for Healthcare Research and Quality Safety Program for Improving Surgical Care and Recovery. Obstetrical & Gynecological Survey. 74(3). 146–147. 2 indexed citations
5.
Livhits, Masha J., et al.. (2019). Same-day discharge is not associated with increased readmissions or complications after thyroid operations. Surgery. 167(1). 117–123. 14 indexed citations
6.
Dawes, Aaron J., Greg D. Sacks, Jack Needleman, et al.. (2019). Injury-specific variables improve risk adjustment and hospital quality assessment in severe traumatic brain injury. The Journal of Trauma: Injury, Infection, and Critical Care. 87(2). 386–392. 8 indexed citations
7.
Ban, Kristen A., Joseph P. Minei, Christine Laronga, et al.. (2017). Executive Summary of the American College of Surgeons/Surgical Infection Society Surgical Site Infection Guidelines—2016 Update. Surgical Infections. 18(4). 379–382. 59 indexed citations
8.
Ko, Clifford Y., Paul E. Bankey, Chris Cribari, et al.. (2017). Expanding the scope of quality measurement in surgery to include nonoperative care: Results from the American College of Surgeons National Surgical Quality Improvement Program emergency general surgery pilot. The Journal of Trauma: Injury, Infection, and Critical Care. 83(5). 837–845. 36 indexed citations
9.
Lawson, Elise H., David S. Zingmond, Anne M. Stey, Bruce L. Hall, & Clifford Y. Ko. (2014). Measuring Risk-Adjusted Value Using Medicare and ACS-NSQIP. Annals of Surgery. 260(4). 668–679. 14 indexed citations
10.
Lawson, Elise H., Rachel Louie, David S. Zingmond, et al.. (2014). Using Both Clinical Registry and Administrative Claims Data to Measure Risk-adjusted Surgical Outcomes. Annals of Surgery. 263(1). 50–57. 37 indexed citations
11.
Raval, Mehul V., Mark E. Cohen, Angela M. Ingraham, et al.. (2010). Improving American College of Surgeons National Surgical Quality Improvement Program Risk Adjustment: Incorporation of a Novel Procedure Risk Score. Journal of the American College of Surgeons. 211(6). 715–723. 70 indexed citations
12.
Wasif, Nabil, Clifford Y. Ko, James J. Farrell, et al.. (2010). Impact of Tumor Grade on Prognosis in Pancreatic Cancer: Should We Include Grade in AJCC Staging?. Annals of Surgical Oncology. 17(9). 2312–2320. 105 indexed citations
13.
Raval, Mehul V., Karl Y. Bilimoria, David J. Bentrem, et al.. (2010). Nodal Evaluation in Wilms' Tumors. Annals of Surgery. 251(3). 559–565. 30 indexed citations
14.
Cohen, Mark E., Karl Y. Bilimoria, Clifford Y. Ko, Karen Richards, & Bruce L. Hall. (2009). Variability in Length of Stay After Colorectal Surgery. Annals of Surgery. 250(6). 901–907. 84 indexed citations
15.
Cohen, Mark E., Karl Y. Bilimoria, Clifford Y. Ko, Karen Richards, & Bruce L. Hall. (2009). Effect of Subjective Preoperative Variables on Risk-Adjusted Assessment of Hospital Morbidity and Mortality. Annals of Surgery. 249(4). 682–689. 48 indexed citations
16.
Bilimoria, Karl Y., David J. Bentrem, Ryan P. Merkow, et al.. (2008). Laparoscopic-assisted vs. Open Colectomy for Cancer: Comparison of Short-term Outcomes from 121 Hospitals. Journal of Gastrointestinal Surgery. 12(11). 2001–2009. 94 indexed citations
17.
SooHoo, Nelson F., David S. Zingmond, & Clifford Y. Ko. (2008). Disparities in the Utilization of High-Volume Hospitals for Total Knee Replacement. Journal of the National Medical Association. 100(5). 559–564. 58 indexed citations
18.
Etzioni, David A., Ninez A. Ponce, Susan H. Babey, et al.. (2004). A population‐based study of colorectal cancer test use. Cancer. 101(11). 2523–2532. 95 indexed citations
19.
Livingston, Edward H. & Clifford Y. Ko. (2002). Use of the Health and Activities Limitation Index as a Measure of Quality of Life in Obesity. Obesity Research. 10(8). 824–832. 38 indexed citations
20.
Ko, Clifford Y.. (1997). Preemptive Analgesia in Patients Undergoing Appendectomy. Archives of Surgery. 132(8). 874–874. 21 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

Explore authors with similar magnitude of impact

Breakdown of academic impact, for papers by John D. Birkmeyer Breakdown of academic impact, for papers by C. Ronald MacKenzie Breakdown of academic impact, for papers by Karl Y. Bilimoria Breakdown of academic impact, for papers by William G. Henderson Breakdown of academic impact, for papers by Gary H. Lyman Breakdown of academic impact, for papers by Justin B. Dimick Breakdown of academic impact, for papers by Shukri F. Khuri Breakdown of academic impact, for papers by H. Gilbert Welch Breakdown of academic impact, for papers by Catherine M. Tangen Breakdown of academic impact, for papers by Lars Pedersen
Rankless by CCL
2026