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Clifford Y. Ko

Bio: Clifford Y. Ko is an academic researcher from American College of Surgeons. The author has contributed to research in topics: Cancer & Population. The author has an hindex of 104, co-authored 514 publications receiving 37029 citations. Previous affiliations of Clifford Y. Ko include University of California, Berkeley & Washington University in St. Louis.


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Journal ArticleDOI
TL;DR: The National Cancer Data Base (NCDB) is a nationwide oncology outcomes database that currently collects information on approximately 70% of all new invasive cancer diagnoses in the United States each year and serves as a powerful clinical surveillance and quality improvement mechanism for cancer programs participating in the ACoS Commission on Cancer (CoC) approvals program.
Abstract: The National Cancer Data Base (NCDB) is a nationwide oncology outcomes database that currently collects information on approximately 70% of all new invasive cancer diagnoses in the United States each year and serves as a powerful clinical surveillance and quality improvement mechanism for cancer programs participating in the American College of Surgeons (ACoS) Commission on Cancer (CoC) approvals program.1–3 Currently, the NCDB receives over one million cancer case reports annually from more than 1,430 hospitals. The NCDB now contains data on more than 21 million cancer patients diagnosed between 1985 and 2005, and is recognized as the largest clinical registry in the world. NCDB data are used to explore trends in cancer care, to examine regional and national benchmarks, and to serve as the basis for quality improvement activities (http://www.facs.org/cancer/ncdb) The purposes of this review are: (1) to describe the NCDB and the data collected; (2) to discuss how the NCDB can be used to study clinical outcomes and the quality of cancer care in the United States; and (3) to describe the clinical care improvement tools provided by the NCDB and the CoC to participating hospitals.

1,555 citations

Journal ArticleDOI
TL;DR: The association of stage IIIa colon cancer with statistically significantly better survival than stage IIb in the new system may reflect current clinical practice, in which stage III patients receive chemotherapy but stage II patients generally do not.
Abstract: Background: The recently revised American Joint Committee on Cancer (AJCC) sixth edition cancer staging system increased the stratification within colon cancer stages II and III defined by the AJCC fifth edition system. Using nationally representative Surveillance, Epidemiology, and End Results (SEER) data, we compared survival rates associated with colon cancer stages defined according to both AJCC systems. Methods: Using SEER data (from January 1, 1991, through December 31, 2000), we identified 119 363 patients with colon adenocarcinoma and included all patients in two analyses by stages defined by AJCC fifth and sixth edition systems. Tumors were stratified by SEER’s “extent of disease” and “number of positive [lymph] nodes” coding schemes. Kaplan‐Meier analyses were used to compare overall and stage-specific 5-year survival. All statistical tests were two-sided. Results: Overall 5-year survival was 65.2%. According to stages defined by the AJCC fifth edition system, 5-year stage-specific survivals were 93.2% for stage I, 82.5% for stage II, 59.5% for stage III, and 8.1% for stage IV. According to stages defined by the AJCC sixth edition system, 5-year stage-specific survivals were 93.2% for stage I, 84.7% for stage IIa, 72.2% for stage IIb, 83.4% for stage IIIa, 64.1% for stage IIIb, 44.3% for stage IIIc, and 8.1% for stage IV. Under the sixth edition system, 5-year survival was statistically significantly better for patients with stage IIIa colon cancer (83.4%) than for patients with stage IIb disease (72.2%) (P<.001). Conclusions: The AJCC sixth edition system for colon cancer stratifies survival more distinctly than the fifth edition system by providing more substages. The association of stage IIIa colon cancer with statistically significantly better survival than stage IIb in the new system may reflect current clinical practice, in which stage III patients receive chemotherapy but stage II patients generally do not. [J Natl Cancer Inst 2004;96:1420 ‐5]

1,414 citations

Journal ArticleDOI
TL;DR: The ACS NSQIP surgical risk calculator is a decision-support tool based on reliable multi-institutional clinical data, which can be used to estimate the risks of most operations.
Abstract: Background Accurately estimating surgical risks is critical for shared decision making and informed consent. The Centers for Medicare and Medicaid Services may soon put forth a measure requiring surgeons to provide patients with patient-specific, empirically derived estimates of postoperative complications. Our objectives were to develop a universal surgical risk estimation tool, to compare performance of the universal vs previous procedure-specific surgical risk calculators, and to allow surgeons to empirically adjust the estimates of risk. Study Design Using standardized clinical data from 393 ACS NSQIP hospitals, a web-based tool was developed to allow surgeons to easily enter 21 preoperative factors (demographics, comorbidities, procedure). Regression models were developed to predict 8 outcomes based on the preoperative risk factors. The universal model was compared with procedure-specific models. To incorporate surgeon input, a subjective surgeon adjustment score, allowing risk estimates to vary within the estimate's confidence interval, was introduced and tested with 80 surgeons using 10 case scenarios. Results Based on 1,414,006 patients encompassing 1,557 unique CPT codes, a universal surgical risk calculator model was developed that had excellent performance for mortality (c-statistic = 0.944; Brier score = 0.011 [where scores approaching 0 are better]), morbidity (c-statistic = 0.816, Brier score = 0.069), and 6 additional complications (c-statistics > 0.8). Predictions were similarly robust for the universal calculator vs procedure-specific calculators (eg, colorectal). Surgeons demonstrated considerable agreement on the case scenario scoring (80% to 100% agreement), suggesting reliable score assignment between surgeons. Conclusions The ACS NSQIP surgical risk calculator is a decision-support tool based on reliable multi-institutional clinical data, which can be used to estimate the risks of most operations. The ACS NSQIP surgical risk calculator will allow clinicians and patients to make decisions using empirically derived, patient-specific postoperative risks.

1,327 citations

Journal ArticleDOI
TL;DR: The aging of the US population will result in significant growth in the demand for surgical services, and surgeons need to develop strategies to manage an increased workload without sacrificing quality of care.
Abstract: The population is expanding and aging. According to the US Census Bureau, the domestic population will increase 7.9% by 2010, and 17.0% by 2020. The fastest growing segment of this population consists of individuals over the age of 65; their numbers are expected to increase 13.3% by 2010 and 53.2% by 2020. Two main factors are responsible for these forecasts. First, we are living longer; life expectancy has increased from 66.7 years for individuals born in 1946 to 76.1 years for those born in 1996.1 Second, the baby boomers (those born between 1946 and 1964) are a wave of population density that will begin to hit retirement age in 2011.2 Older individuals require more medical services relative to their younger counterparts. The National Hospital Discharge Survey (NHDS) reported that in 1999, patients aged 65 years or older comprised 12% of the population, but constituted 40% of hospital discharges and 48% of days of inpatient care.3 As the proportion of elderly patients in the population increases, the medical system will face new challenges. Will there be enough surgeons to meet the increased demand for surgical services? The last decade has been notable for a perception of balance with regard to the physician supply relative to demand. Against this calm background, we sought to isolate and predict the effect of the aging population on the use of surgical services and the need for surgeons. We hypothesized that the surgical workload will increase significantly over the next 2 decades due in large part to the aging of the US population. Toward evaluating this hypothesis, we employed an approach based upon historical patterns of care. Data from national surveys of medical and surgical services were used to establish a profile of age-specific rates of surgical use. This profile was then used to model the impact of forecasted population shifts on surgical work.

748 citations

Journal ArticleDOI
TL;DR: ACS-NSQIP indicates that surgical outcomes improve across all participating hospitals in the private sector, and improvement is reflected for both poor- and well-performing facilities.
Abstract: Background/Objective: The National Surgical Quality Improvement Program (NSQIP) has demonstrated quality improvement in the VA and pilot study of 14 academic institutions. The objective was to show that American College of Surgeons (ACS)-NSQIP helps all enrolled hospitals. Methods: ACS-NSQIP data was used to evaluate improvement in hospitals longitudinally over 3 years (2005-2007). Improvement was defined as reduction in risk-adjusted "Observed/Expected" (O/E) ratios between periods with risk adjustment held constant. Multivariable logistic regression-based adjustment was performed and included indicators for procedure groups. Additionally, morbidity counts were modeled using a negative binomial model, to estimate the number of avoided complications. Results: Multiple perspectives reflected improvement over time. In the analysis of 118 hospitals (2006-2007), 66% of hospitals improved risk-adjusted mortality (mean O/E improvement: 0.174; P < 0.05) and 82% improved risk adjusted complication rates (mean improvement: 0.114; P < 0.05). Correlations between starting O/E and improvement (0.834 for mortality, 0.652 for morbidity), as well as relative risk, revealed that initially worse-performing hospitals had more likelihood of improvement. Nonetheless, well-performing hospitals also improved. Modeling morbidity counts, 183 hospitals (2007), avoided ~9598 potential complications: ~52/hospital. Due to sampling this may represent only 1 of 5 to lof 10 of the true total. Improvement reflected aggregate performance across all types of hospitals (academic/community, urban/rural). Changes in patient risk over time had important contributions to the effect. Conclusions: ACS-NSQIP indicates that surgical outcomes improve across all participating hospitals in the private sector. Improvement is reflected for both poor- and well-performing facilities. NSQIP hospitals appear to be avoiding substantial numbers of complications- improving care, and reducing costs. Changes in risk over time merit further study.

703 citations


Cited by
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Journal ArticleDOI
01 Nov 2009-Thyroid
TL;DR: Evidence-based recommendations are developed to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer and represent, in the authors' opinion, contemporary optimal care for patients with these disorders.
Abstract: Background: Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer. Methods: The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Gr...

10,501 citations

Journal ArticleDOI
04 Nov 2009-Thyroid
TL;DR: Evidence-based recommendations in response to the appointment as an independent task force by the American Thyroid Association to assist in the clinical management of patients with thyroid nodules and differentiated thyroid cancer represent, in the authors' opinion, contemporary optimal care for patients with these disorders.
Abstract: Background: Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the publication of the American Thyroid Association's guidelines for the management of these disorders was published in 2006, a large amount of new information has become available, prompting a revision of the guidelines. Methods: Relevant articles through December 2008 were reviewed by the task force and categorized by topic and level of evidence according to a modified schema used by the United States Preventative Services Task Force. Results: The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to optimal surgical management, radioiodine remnant ablation, a...

7,525 citations

Journal ArticleDOI
TL;DR: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors.
Abstract: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

6,968 citations

01 Jan 2010
TL;DR: Since the publication of the American Association for the Study of Liver Diseases (AASLD) practice guidelines on the management of hepatocellular carcinoma (HCC) in 2005, new information has emerged that requires that the guidelines be updated.
Abstract: Since the publication of the American Association for the Study of Liver Diseases (AASLD) practice guidelines on the management of hepatocellular carcinoma (HCC) in 2005, new information has emerged that requires that the guidelines be updated. The full version of the new guidelines is available on the AASLD Web site at http://www.aasld.org/practiceguidelines/ Documents/Bookmarked%20Practice%20Guidelines/ HCCUpdate2010.pdf. Here, we briefly describe only new or changed recommendations.

6,642 citations