Publications
Department of Medicine faculty members published more than 3,000 peer-reviewed articles in 2022.
2012
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BACKGROUND & AIMS
Almost all colorectal polyps ≤ 5 mm are benign, yet current practice requires costly pathologic analysis. We aimed to develop and evaluate the validity of a simple narrow-band imaging (NBI)-based classification system for differentiating hyperplastic from adenomatous polyps.
METHODS
The study was conducted in 4 phases: (1) evaluation of accuracy and reliability of histologic prediction by NBI-experienced colonoscopists; (2) development of a classification based on color, vessels, and surface pattern criteria, using a modified Delphi method; (3) validation of the component criteria by people not experienced in endoscopy or NBI analysis (25 medical students, 19 gastroenterology fellows) using 118 high-definition colorectal polyp images of known histology; and (4) validation of the classification system by NBI-trained gastroenterology fellows, using still images. We performed a pilot evaluation during real-time colonoscopy.
RESULTS
We developed a classification system for the endoscopic diagnosis of colorectal polyp histology and established its predictive validity. When all 3 criteria were used, the specificity ranged from 94.9% to 100% and the combined sensitivity ranged from 8.5% to 61.0%. The specificities of the individual criteria were lower although the sensitivities were higher. During real-time colonoscopy, endoscopists made diagnoses with high confidence for 75% of consecutive small colorectal polyps, with 89% accuracy, 98% sensitivity, and 95% negative predictive values.
CONCLUSIONS
We developed and established the validity of an NBI classification system that can be used to diagnose colorectal polyps. In preliminary real-time evaluation, the system allowed endoscopic diagnoses of colorectal polyp histology.
View on PubMed2012
BACKGROUND & AIMS
The relationship between inflammatory bowel disease (IBD) and the incidence and mortality of colorectal adenocarcinoma (CRC) has not been evaluated recently.
METHODS
We calculated the incidence and standardized incidence and mortality rate ratios of CRC among adult individuals with intact colons using Kaiser Permanente of Northern California's database of members with IBD and general membership data for the period of 1998 to June 2010 (data through 2008 were used to calculate mortality). We also evaluated trends in medication use and rates of cancer detection over time.
RESULTS
We identified 29 cancers among persons with Crohn's disease (CD) and 53 among persons with ulcerative colitis (UC). Overall, the incidence rates of cancer among individuals with CD, UC, or in the general membership were 75.0, 76.0, and 47.1, respectively, per 100,000 person-years. In the general population, the incidence of CRC was 21% higher in 2007-2010 than in 1998-2001 (P for trend, <.0001), coincident with the growth of CRC screening programs. The incidence of CRC among individuals with CD or UC was 60% higher than in the general population (95% confidence interval [CI] for CD, 20%-200%; 95% CI for UC, 30%-200%) and was stable over time (P for trend was as follows: CD, .98; UC, .40). During 1998-2008, the standardized mortality ratio for CRC in individuals with CD was 2.3 (95% CI, 1.6-3.0) and 2.0 in those with UC (95% CI, 1.3-2.7). Over the study period, anti-tumor necrosis factor agents replaced other therapies for CD and UC; the rate of colonoscopy increased by 33% among patients with CD and decreased by 9% in those with UC.
CONCLUSIONS
From 1998 to 2010, the incidence of CRC in patients with IBD was 60% higher than in the general population and essentially stable over time.
View on PubMed2012
BACKGROUND
Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an overall poor prognosis. A simple-to-use staging system for IPF may improve prognostication, help guide management, and facilitate research.
OBJECTIVE
To develop a multidimensional prognostic staging system for IPF by using commonly measured clinical and physiologic variables.
DESIGN
A clinical prediction model was developed and validated by using retrospective data from 3 large, geographically distinct cohorts.
SETTING
Interstitial lung disease referral centers in California, Minnesota, and Italy.
PATIENTS
228 patients with IPF at the University of California, San Francisco (derivation cohort), and 330 patients at the Mayo Clinic and Morgagni-Pierantoni Hospital (validation cohort).
MEASUREMENTS
The primary outcome was mortality, treating transplantation as a competing risk. Model discrimination was assessed by the c-index, and calibration was assessed by comparing predicted and observed cumulative mortality at 1, 2, and 3 years.
RESULTS
Four variables were included in the final model: gender (G), age (A), and 2 lung physiology variables (P) (FVC and Dlco). A model using continuous predictors (GAP calculator) and a simple point-scoring system (GAP index) performed similarly in derivation (c-index of 70.8 and 69.3, respectively) and validation (c-index of 69.1 and 68.7, respectively). Three stages (stages I, II, and III) were identified based on the GAP index with 1-year mortality of 6%, 16%, and 39%, respectively. The GAP models performed similarly in pooled follow-up visits (c-index ≥71.9).
LIMITATION
Patients were drawn from academic centers and analyzed retrospectively.
CONCLUSION
The GAP models use commonly measured clinical and physiologic variables to predict mortality in patients with IPF.
View on PubMed2012
2012