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Dive into the research topics where Wei K. Zhao is active.

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Featured researches published by Wei K. Zhao.


Clinical Gastroenterology and Hepatology | 2013

Variation of adenoma prevalence by age, sex, race, and colon location in a large population: implications for screening and quality programs.

Douglas A. Corley; Christopher D. Jensen; Amy R. Marks; Wei K. Zhao; Jolanda de Boer; Theodore R. Levin; Chyke A. Doubeni; Bruce Fireman; Charles P. Quesenberry

BACKGROUND & AIMS Reliable community-based colorectal adenoma prevalence estimates are needed to inform colonoscopy quality standards and to estimate patient colorectal cancer risks; however, minimal data exist from populations with large numbers of diverse patients and examiners. METHODS We evaluated the prevalence of adenomas detected by sex, age, race/ethnicity, and colon location among 20,792 Kaiser Permanente Northern California members ≥50 years of age who received a screening colonoscopy examination (102 gastroenterologists, 2006-2008). RESULTS Prevalence of detected adenomas increased more rapidly with age in the proximal colon (adjusted odds ratio [OR], 2.39; 95% confidence interval [CI], 2.05-2.80; 70-74 vs 50-54 years) than in the distal colon (OR, 1.89; 95% CI, 1.63-2.19). Prevalence was higher among men vs women at all ages (OR, 1.77; 95% CI, 1.66-1.89), increasing in men from 25% to 39% at ≥70 years and in women from 15% at 50-54 years to 26% (P < .001). Proximal adenoma prevalence was higher among blacks than whites (OR, 1.26; 95% CI, 1.04-1.54), although total prevalence was similar, including persons <60 years old (OR, 1.17; 95% CI, 0.91-1.50). CONCLUSIONS Prevalence of detected adenomas increases substantially with age and is much higher in men; proximal adenomas are more common among blacks than whites, although the total prevalence and the prevalence for ages <60 years were similar by race. These demographic differences are such that current adenoma detection guidelines may not be valid, without adjustment, for comparing providers serving different populations. The variation in prevalence and location may also have implications for the effectiveness of screening methods in different demographic groups.


Clinical Gastroenterology and Hepatology | 2010

Citalopram Provides Little or No Benefit in Nondepressed Patients With Irritable Bowel Syndrome

Uri Ladabaum; Annie Sharabidze; Theodore R. Levin; Wei K. Zhao; Elaine Chung; Peter Bacchetti; Chengshi Jin; Barbara Grimes; Craig J. Pepin

BACKGROUND & AIMS Data on the benefit of selective serotonin reuptake inhibitors (SSRIs) in irritable bowel syndrome (IBS) are conflicting. The longitudinal relationship between clinical symptoms and sensitivity to barostat-mediated rectal distension in IBS remains unclear. We assessed the benefit of citalopram and explored the relationships between symptoms, quality of life (QOL), and rectal sensitivity to barostat distension in non-depressed IBS patients. METHODS Patients from primary, secondary, and tertiary care settings were randomly assigned to receive citalopram (20 mg/day for 4 weeks, then 40 mg/day for 4 weeks) or placebo in a study with double-masking and concealed allocation. Symptoms were assessed weekly, and IBS-QOL and rectal sensation by barostat were assessed at the beginning and end of the study. RESULTS Patients receiving citalopram did not achieve a higher rate of adequate relief of IBS symptoms than patients receiving placebo (12/27 [44%] vs 15/27 [56%]; P = .59), regardless of IBS subtype. The odds ratio for weekly response with citalopram vs placebo was 0.80 (95% confidence interval, 0.61-1.04). Improvements in specific symptom and IBS-QOL scores were not superior for citalopram. Changes in IBS-QOL score and pressure eliciting pain showed a modest correlation (r = 0.33; 95% confidence interval, 0.03-0.57), but changes in symptoms and IBS-QOL scores or rectal sensitivity were not correlated substantially. CONCLUSIONS Citalopram was not superior to placebo in treating non-depressed IBS patients. Changes in symptoms were not substantially correlated with changes in rectal sensation assessed by barostat. Any benefit of citalopram in non-depressed IBS patients is likely to be modest at best.


Annals of Internal Medicine | 2016

Fecal Immunochemical Test Program Performance Over 4 Rounds of Annual Screening: A Retrospective Cohort Study

Christopher D. Jensen; Douglas A. Corley; Virginia P. Quinn; Chyke A. Doubeni; Ann G. Zauber; Jeffrey K. Lee; Wei K. Zhao; Amy R. Marks; Joanne E. Schottinger; Nirupa R. Ghai; Alexander Lee; Richard Contreras; Carrie N. Klabunde; Charles P. Quesenberry; Theodore R. Levin; Pauline A. Mysliwiec

Context The fecal immunochemical test is an effective way to screen for colorectal cancer, but we know more about how well it does the first time it is used and less about how well it does in later years with repeated testing. Contribution The researchers show that, after 4 years of repeated testing, patients continued to use the test and it continued to identify colorectal cancer. Caution This study did not measure whether identification of cancer changed outcomes. Implication The fecal immunochemical test is acceptable and effective for repeated testing. Colorectal cancer (CRC) is the second leading cause of cancer death in the United States (13), and screening with fecal occult blood tests (FOBTs) reduces CRC incidence and mortality (46). In randomized trials (711), annual or biennial guaiac-based FOBTs reduced CRC incidence by 17% to 20% and CRC mortality by 15% to 33%. Thus, the U.S. Preventive Services Task Force (4) and U.S. Multi-Society Task Force on Colorectal Cancer (12) recommend annual FOBT as an option for CRC screening for average-risk patients, defined as those aged 50 to 75 years with no history of CRC or adenoma, with no first-degree relatives with CRC, and who are not up to date with CRC screening according to other methods (that is, sigmoidoscopy within 5 years or colonoscopy within 10 years). Annual highly sensitive FOBTs are believed to be as effective as screening colonoscopy performed every 10 years if levels of adherence are high (13), although colonoscopy is recommended for those with a family history of CRC. Fecal blood tests are noninvasive and can be delivered by mail (14). In contrast to guaiac-based stool tests, fecal immunochemical test (FIT) screening can be done without dietary or medication restrictions, which allows it to achieve higher patient acceptance in organized CRC screening programs (15). This test also has higher detection rates for CRC and advanced adenomas than guaiac-based stool tests (1517). In a recent meta-analysis (18), the sensitivity of a single FIT application was 79% for CRC diagnosed within 2 years of testing; however, little is known about performance characteristics over several rounds of annual screening, particularly in community practice. The present study was conducted to evaluate FIT sensitivity for CRC and other performance characteristics over 4 rounds of annual testing in a U.S. community-based CRC screening program. Methods Study Population This retrospective longitudinal study was performed in a fixed cohort of Kaiser Permanente Northern California (KPNC) and Southern California (KPSC) health plan members. These integrated health care delivery organizations serve approximately 7 million persons in urban, suburban, and semirural regions throughout California. Kaiser Permanente health plan membership in California is diverse and similar in socioeconomic characteristics to the regions census demographics (1921). Study Oversight The study was approved by the institutional review boards of KPNC and KPSC, both of which waived the requirement for informed consent. The listed authors had sole responsibility for the study design, data collection, decision to submit the manuscript for publication, and drafting of the manuscript. This study was conducted within the National Cancer Institutefunded Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium, which conducts multisite, coordinated, transdisciplinary research to evaluate and improve cancer-screening processes. Organized CRC Screening Program The KPNC and KPSC initiated similar organized FIT screening programs between 2006 and 2008; the KPNC program has been described previously (14). Briefly, each year, the programs mail a FIT kit to eligible health plan members aged 50 to 75 years without a record of a colonoscopy within 10 years, sigmoidoscopy within 5 years, or fecal blood test within the prior year. The kit includes the FIT (OC FIT-CHEK; Polymedco), a standardized letter from the patients primary care provider, directions for completing and mailing the test, and a preprinted laboratory requisition order form. Outreach includes in-person, mail, secure e-mail, and telephone reminders as needed. The kits are returned by mail to regional laboratories and analyzed on or shortly after the return date using an OC-Sensor Diana automated system (Polymedco) with a cutoff level of 20 g of hemoglobin/g of buffer for a positive result. Patients with a positive FIT result are referred for follow-up colonoscopy. Study Eligibility Criteria and Participant Tracking The study cohort included CRC screening program participants aged 50 to 70 years on the date an initial kit was mailed to them in 2007 or 2008. Patients were excluded if they had been enrolled in the health plan for less than 1 year before the round 1 FIT mail date (to allow for the recording of prior out-of-system endoscopy procedures). They were also excluded if they were mailed a kit but subsequently had sigmoidoscopy or colonoscopy, were diagnosed with CRC, died, or terminated membership in the health plan before returning the initial FIT or within 1 year after their round 1 mail date if no FIT was returned. A total of 670841 health plan members was mailed the initial kit in 2007 or 2008 and met the study eligibility criteria; 323349 (48.2%) returned a FIT within 1 year after the mail date (Figure). The analytic cohort comprised these round 1 participants who were tracked from their baseline mail date (cohort entry) through up to 4 rounds of testing for mail dates; result dates; results (positive or negative); whether follow-up colonoscopy was performed within 1 year after a positive FIT result; and diagnoses of adenoma, adenoma with advanced histology, and CRC. Cohort members were followed for CRC through the follow-up screening rounds, even if they subsequently became ineligible for screening because of sigmoidoscopy or colonoscopy. Patients were censored at the time of CRC diagnosis, death, or termination of membership in the health plan if they did not rejoin. Figure. Study flow diagram.* The figure includes 1192 patients with CRC who were screened by FIT the year before diagnosis. Further, there were 118 additional patients with CRC diagnosed more than 1 y beyond the FIT screening date and 101 additional patients diagnosed with CRC who either crossed over to endoscopy in subsequent rounds or terminated health plan membership but then rejoined. CRC = colorectal cancer; FIT = fecal immunochemical test. * Shading indicates where patients were censored or became ineligible for subsequent FIT screening. Patients were eligible for the initial FIT mailing if they were aged 50 to 70 y and had 1 y of membership. See Methods section for exclusions. Number censored because of CRC and includes patients with CRC diagnosed within 1 y after their FIT result. Defining Annual Screening Episodes For each patient, the initial kit mail date in 2007 or 2008 was the anchor date for round 1 and for each subsequent round of testing. However, because subsequent mailing dates varied each round, mail dates within 3 months before to 12 months after each subsequent rounds anchor date were counted as having been distributed during that specific round. For example, a patient with a round 1 mail date of 15 March 2007 had subsequent anchor dates of 15 March for rounds 2 through 4 (2008, 2009, and 2010, respectively). If their next FIT was mailed on 15 January 2008, the test was considered to be distributed in round 2 because the second mail date occurred within 3 months of the round 2 anchor date. The FIT results recorded within 1 year of each mail date, and colonoscopies performed and adenomas or CRC diagnosed within 1 year after FIT results, were considered part of a single screening episode for the round when the FIT was distributed. Among round 1 participants, FITs with no recorded mail dates returned in rounds 2 through 4 were assumed to be distributed through in-reach methods (such as a clinic visit) and were counted in the follow-up round returned. In general, the first result per patient was counted in any given round. The earliest possible date of cohort entry (first mail date) was 1 January 2007, and the last possible date of follow-up was 31 December 2013 (12 months after the last possible FIT result date of 31 December 2012). Data Sources The FIT-related dates and results were obtained from the CRC screening program and laboratory databases for each region, respectively. Endoscopy procedures were identified using Current Procedural Terminology codes (22). Adenoma diagnoses used Systematized Nomenclature of Medicine codes. Prior validation studies have confirmed high levels of sensitivity and accuracy for capture of colonoscopy examinations and assignment of adenoma status (23). Colorectal adenocarcinomas and disease stage were obtained from the KPNC and KPSC cancer registries, which report to the SEER (Surveillance, Epidemiology, and End Results) registry. Cancer databases capture more than 98% of cancer diagnoses within the KPNC and KPSC populations. Advanced-stage cancer was defined as stage III (regional disease with spread to regional lymph nodes only) or stage IV (distant metastasis) according to the American Joint Committee on Cancer staging system; for patients who did not have such staging, advanced-stage cancer was defined as code 3 (disease in the regional lymph nodes), code 4 (regional disease with direct extension and spread to regional lymph nodes), or code 7 (distant metastasis) according to the SEER Program Coding and Staging Manual 2013 (24). Data Analysis The following performance characteristics were calculated for each round of screening and overall: 1) participation (percentage of eligible patients who were distributed and completed a FIT within 1 year of their mailing date), 2) FIT positivity (percentage of participants who completed FITs and had positive results), 3) follow-up colonoscopy (per


Clinical Gastroenterology and Hepatology | 2012

Diagnosis, Comorbidities, and Management of Irritable Bowel Syndrome in Patients in a Large Health Maintenance Organization

Uri Ladabaum; Erin Boyd; Wei K. Zhao; Ajitha Mannalithara; Annie Sharabidze; Gurkirpal Singh; Elaine Chung; Theodore R. Levin

BACKGROUND & AIMS Irritable bowel syndrome (IBS) imposes significant clinical and economic burdens. We aimed to characterize practice patterns for patients with IBS in a large health maintenance organization, analyzing point of diagnosis, testing, comorbidities, and treatment. METHODS Members of Kaiser Permanente Northern California who were diagnosed with IBS were matched to controls by age, sex, and period of enrollment. We compared rates of testing, comorbidities, and interventions. RESULTS From 1995-2005, IBS was diagnosed in 141,295 patients (mean age, 46 years; standard deviation, 17 years; 74% female). Internists made 68% of diagnoses, gastroenterologists 13%, and others 19%. Lower endoscopy did not usually precede IBS diagnosis. Patients with IBS were more likely than controls to have blood, stool, endoscopic, and radiologic tests and to undergo abdominal or pelvic operations (odds ratios, 1.5-10.7; all P < .0001). Only 2.7% were tested for celiac disease, and only 1.8% were eventually diagnosed with inflammatory bowel disease. Chronic pain syndromes, anxiety, and depression were more common among IBS patients than among controls (odds ratios, 2.7-4.6; all P < .0001). Many patients with IBS were treated with anxiolytics (61%) and antidepressants (55%). Endoscopic and radiologic testing was most strongly associated with having IBS diagnosed by a gastroenterologist. Psychotropic medication use was most strongly associated with female sex. CONCLUSIONS In a large, managed care cohort, most diagnoses of IBS were made by generalists, often without endoscopic evaluation. Patients with IBS had consistently higher rates of testing, chronic pain syndromes, psychiatric comorbidity, and operations than controls. Most patients with IBS were treated with psychiatric medications.


Gut | 2018

Effectiveness of screening colonoscopy in reducing the risk of death from right and left colon cancer: a large community-based study

Chyke A. Doubeni; Douglas A. Corley; Virginia P. Quinn; Christopher D. Jensen; Ann G. Zauber; Michael Goodman; Jill Johnson; Shivan J. Mehta; Tracy A Becerra; Wei K. Zhao; Joanne Schottinger; V. Paul Doria-Rose; Theodore R. Levin; Noel S. Weiss; Robert H. Fletcher

Objective Screening colonoscopys effectiveness in reducing colorectal cancer mortality risk in community populations is unclear, particularly for right-colon cancers, leading to recommendations against its use for screening in some countries. This study aimed to determine whether, among average-risk people, receipt of screening colonoscopy reduces the risk of dying from both right-colon and left-colon/rectal cancers. Design We conducted a nested case–control study with incidence-density matching in screening-eligible Kaiser Permanente members. Patients who were 55–90 years old on their colorectal cancer death date during 2006–2012 were matched on diagnosis (reference) date to controls on age, sex, health plan enrolment duration and geographical region. We excluded patients at increased colorectal cancer risk, or with prior colorectal cancer diagnosis or colectomy. The association between screening colonoscopy receipt in the 10-year period before the reference date and colorectal cancer death risk was evaluated while accounting for other screening exposures. Results We analysed 1747 patients who died from colorectal cancer and 3460 colorectal cancer-free controls. Compared with no endoscopic screening, receipt of a screening colonoscopy was associated with a 67% reduction in the risk of death from any colorectal cancer (adjusted OR (aOR)=0.33, 95% CI 0.21 to 0.52). By cancer location, screening colonoscopy was associated with a 65% reduction in risk of death for right-colon cancers (aOR=0.35, CI 0.18 to 0.65) and a 75% reduction for left-colon/rectal cancers (aOR=0.25, CI 0.12 to 0.53). Conclusions Screening colonoscopy was associated with a substantial and comparably decreased mortality risk for both right-sided and left-sided cancers within a large community-based population.


JAMA | 2017

Association Between Time to Colonoscopy After a Positive Fecal Test Result and Risk of Colorectal Cancer and Cancer Stage at Diagnosis

Douglas A. Corley; Christopher D. Jensen; Virginia P. Quinn; Chyke A. Doubeni; Ann G. Zauber; Jeffrey K. Lee; Joanne E. Schottinger; Amy R. Marks; Wei K. Zhao; Nirupa R. Ghai; Alexander T. Lee; Richard Contreras; Charles P. Quesenberry; Bruce Fireman; Theodore R. Levin

Importance The fecal immunochemical test (FIT) is commonly used for colorectal cancer screening and positive test results require follow-up colonoscopy. However, follow-up intervals vary, which may result in neoplastic progression. Objective To evaluate time to colonoscopy after a positive FIT result and its association with risk of colorectal cancer and advanced-stage disease at diagnosis. Design, Setting, and Participants Retrospective cohort study (January 1, 2010-December 31, 2014) within Kaiser Permanente Northern and Southern California. Participants were 70 124 patients aged 50 through 70 years eligible for colorectal cancer screening with a positive FIT result who had a follow-up colonoscopy. Exposures Time (days) to colonoscopy after a positive FIT result. Main Outcomes and Measures Risk of any colorectal cancer and advanced-stage disease (defined as stage III and IV cancer). Odds ratios (ORs) and 95% CIs were adjusted for patient demographics and baseline risk factors. Results Of the 70 124 patients with positive FIT results (median age, 61 years [IQR, 55-67 years]; men, 52.7%), there were 2191 cases of any colorectal cancer and 601 cases of advanced-stage disease diagnosed. Compared with colonoscopy follow-up within 8 to 30 days (n = 27 176), there were no significant differences between follow-up at 2 months (n = 24 644), 3 months (n = 8666), 4 to 6 months (n = 5251), or 7 to 9 months (n = 1335) for risk of any colorectal cancer (cases per 1000 patients: 8-30 days, 30; 2 months, 28; 3 months, 31; 4-6 months, 31; and 7-9 months, 43) or advanced-stage disease (cases per 1000 patients: 8-30 days, 8; 2 months, 7; 3 months, 7; 4-6 months, 9; and 7-9 months, 13). Risks were significantly higher for examinations at 10 to 12 months (n = 748) for any colorectal cancer (OR, 1.48 [95% CI, 1.05-2.08]; 49 cases per 1000 patients) and advanced-stage disease (OR, 1.97 [95% CI, 1.14-3.42]; 19 cases per 1000 patients) and more than 12 months (n = 747) for any colorectal cancer (OR, 2.25 [95% CI, 1.89-2.68]; 76 cases per 1000 patients) and advanced-stage disease (OR, 3.22 [95% CI, 2.44-4.25]; 31 cases per 1000 patients). Conclusions and Relevance Among patients with a positive fecal immunochemical test result, compared with follow-up colonoscopy at 8 to 30 days, follow-up after 10 months was associated with a higher risk of colorectal cancer and more advanced-stage disease at the time of diagnosis. Further research is needed to assess whether this relationship is causal.


Epidemiology | 2015

Chronic kidney disease and risk of renal cell carcinoma: differences by race.

Jonathan N. Hofmann; Douglas A. Corley; Wei K. Zhao; Joanne S. Colt; Brian Shuch; Wong-Ho Chow; Mark P. Purdue

Background: The incidence of renal cell carcinoma in the United States differs by race/ethnicity. To better understand these disparities, we conducted a nested case–control study investigating renal cell carcinoma risk factors across racial/ethnic groups within the Kaiser Permanente Northern California health care network. Methods: Our study included 3136 renal cell carcinoma cases (2152 whites, 293 blacks, 425 Hispanics, and 255 Asians) diagnosed between 1998 and 2008 and 31031 individually matched controls (21478 whites, 2836 blacks, 4147 Hispanics, and 2484 Asians). Risk of renal cell carcinoma was assessed in relation to smoking status, body mass index (BMI), hypertension, and chronic kidney disease. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression, and population attributable risk (PAR) to estimate by race the proportion of cases attributable to hypertension and chronic kidney disease. Results: The association between chronic kidney disease and renal cell carcinoma differed markedly by race (Pinteraction < 0.001), with associations observed among blacks (OR = 10.4 [95% CI = 6.0–17.9]), Asians (5.1 [2.2–11.7]), and Hispanics (2.3 [1.1–4.6]) but not whites (1.1 [0.6–1.9]). Hypertension, high BMI, and smoking were associated with renal cell carcinoma, but findings generally did not differ by race. Relative to other racial/ethnic groups, blacks had the highest proportion of renal cell carcinoma incidence attributable to hypertension and chronic kidney disease (combined, PAR = 37%; hypertension only, PAR = 27%; chronic kidney disease, PAR = 10%). Conclusions: Our findings suggest that hypertension and chronic kidney disease likely have contributed to the observed excess in renal cell carcinoma incidence among blacks compared with whites.


Clinical Gastroenterology and Hepatology | 2015

Adjusting for Patient Demographics has Minimal Effects on Rates of Adenoma Detection in a Large, Community-Based Setting

Christopher D. Jensen; Chyke A. Doubeni; Virginia P. Quinn; Theodore R. Levin; Ann G. Zauber; Joanne E. Schottinger; Amy R. Marks; Wei K. Zhao; Jeffrey K. Lee; Nirupa R. Ghai; Jennifer L. Schneider; Bruce Fireman; Charles P. Quesenberry; Douglas A. Corley

BACKGROUND & AIMS Reliable estimates of adenoma detection rates (ADRs) are needed to inform colonoscopy quality standards, yet little is known about the contributions of patient demographics to variation in ADRs. We evaluated the effects of adjusting for patient age, race/ethnicity, and family history of colorectal cancer on variations in ADRs and the relative rank order of physicians. METHODS In a retrospective cohort study, we collected data from Kaiser Permanente Northern California members who were ≥ 50 years old who received colonoscopies from 2006 through 2008. We evaluated ADRs (before and after adjustment for age, sex, race/ethnicity, and family history of colorectal cancer) for 102 endoscopists who performed 108,662 total colonoscopies and 20,792 screening colonoscopies. Adenomas were identified from the pathology database, and cancers were detected by using the Kaiser Permanente Northern California cancer registry. RESULTS About two-thirds of examiners had unadjusted ADRs for screening exams that met gastroenterology society guidelines (>25% for men and >15% for women), although rates of detection varied widely (7.7%-61.5% for male patients and 1.7%-45.6% for female patients). Adjusting for case mix reduced the variation in detection rates (from 8-fold to 3-fold for male patients and from 27-fold to 5-fold for female patients), but the median change in physician order by detection rate was just 2 ranks, and few physicians changed quartiles of detection. For example, only 3 of 102 endoscopists moved into and 3 out of the lowest quartile of ADR. CONCLUSIONS In a community-based setting, most endoscopists met the ADR standards, although there was wide variation in ADRs, which was similar to that reported from academic and referral settings. Case-mix adjustment reduced variability but had only small effects on differences in ADRs between physicians, and only a small percentage of physicians changed quartiles of detection. Adjustments to ADRs are therefore likely only needed in settings in which physicians have very different patient demographics, such as in sex or age. Moderate differences in patient demographics between physicians are unlikely to substantially change rates of adenoma detection.


Gastrointestinal Endoscopy | 2017

Endoscopist fatigue estimates and colonoscopic adenoma detection in a large community-based setting

Alexander T. Lee; Christopher D. Jensen; Amy R. Marks; Wei K. Zhao; Chyke A. Doubeni; Ann G. Zauber; Virginia P. Quinn; Theodore R. Levin; Douglas A. Corley

BACKGROUND AND AIMS Endoscopist fatigue may impact colonoscopy quality, but prior studies conflict, and minimal data exist from community-based practices where most colonoscopies are performed. METHODS Within a large, community-based integrated healthcare system, we evaluated the associations among 4 measures of endoscopist fatigue and colonoscopic adenoma detection from 2010 to 2013. Fatigue measures included afternoon versus morning colonoscopy and the number of GI procedures performed before a given colonoscopy, including consideration of prior procedure complexity. Analyses were adjusted for potential confounders using multivariate logistic regression. RESULTS We identified 126 gastroenterologists who performed 259,064 total GI procedures (median, 6 per day; range, 1-24), including 76,445 screening and surveillance colonoscopies. Compared with morning examinations, colonoscopies in the afternoon were not associated with lower adenoma detection for screening examinations, surveillance examinations, or their combination (OR for combination, .99; 95% CI, .96-1.03). The number of procedures performed before a given colonoscopy, with or without consideration of prior procedure complexity, was also not inversely associated with adenoma detection (OR for adenoma detection for colonoscopies in the fourth quartile of fatigue based on the number of prior procedures performed vs colonoscopies performed as the first procedure of the day, .99; 95% CI, .94-1.04). CONCLUSIONS In a large community-based setting, adenoma detection for screening and surveillance colonoscopies were not associated with either time of day or the number of prior procedures performed by the endoscopist, within the range of procedure volumes evaluated. The lack of association persisted after accounting for prior procedure complexity.


Gastroenterology | 2018

Effects of Organized Colorectal Cancer Screening on Cancer Incidence and Mortality in a Large, Community-based Population

Theodore R. Levin; Douglas A. Corley; Christopher D. Jensen; Joanne E. Schottinger; Virginia P. Quinn; Ann G. Zauber; Jeffrey K. Lee; Wei K. Zhao; Natalia Udaltsova; Nirupa R. Ghai; Alexander T. Lee; Charles P. Quesenberry; Bruce Fireman; Chyke A. Doubeni

BACKGROUND & AIMS Little information is available on the effectiveness of organized colorectal cancer (CRC) screening on screening uptake, incidence, and mortality in community-based populations. METHODS We contrasted screening rates, age-adjusted annual CRC incidence, and incidence-based mortality rates before (baseline year 2000) and after (through 2015) implementation of organized screening outreach, from 2007 through 2008 (primarily annual fecal immunochemical testing and colonoscopy), in a large community-based population. Among screening-eligible individuals 51-75 years old, we calculated annual up-to-date status for cancer screening (by fecal test, sigmoidoscopy, or colonoscopy), CRC incidence, cancer stage distributions, and incidence-based mortality. RESULTS Initiation of organized CRC screening significantly increased the up-to-date status of screening, from 38.9% in 2000 to 82.7% in 2015 (P < .01). Higher rates of screening were associated with a 25.5% reduction in annual CRC incidence between 2000 and 2015, from 95.8 to 71.4 cases/100,000 (P < .01), and a 52.4% reduction in cancer mortality, from 30.9 to 14.7 deaths/100,000 (P < .01). Increased screening was initially associated with increased CRC incidence, due largely to greater detection of early-stage cancers, followed by decreases in cancer incidence. Advanced-stage CRC incidence rates decreased 36.2%, from 45.9 to 29.3 cases/100,000 (P < .01), and early-stage CRC incidence rates decreased 14.5%, from 48.2 to 41.2 cases/100,000 (P < .04). CONCLUSIONS Implementing an organized CRC screening program in a large community-based population rapidly increased screening participation to the ≥80% target set by national organizations. Screening rates were sustainable and associated with substantial decreases in CRC incidence and mortality within short time intervals, consistent with early detection and cancer prevention.

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Chyke A. Doubeni

University of Pennsylvania

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Ann G. Zauber

Memorial Sloan Kettering Cancer Center

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Jeffrey K. Lee

University of California

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