Christine Piette

Stanford Medicine, Stanford, California, United States

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Publications (35)175.35 Total impact

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    ABSTRACT: Limited data are available on the follow-up of patients with incomplete colonoscopy following positive faecal occult blood testing. Our study aimed to determine the proportion of and reasons for incomplete colonoscopies, the proportion of patients who completed colonic evaluations, the methods used and the subsequent findings. A total of 9483 colonoscopies performed after positive testing in a colorectal cancer screening programme setting were included. The study was prospective for index colonoscopy findings and partly retrospective for follow-up. Overall 297 colonoscopies were incomplete (3.2%). A secondary colonic evaluation was deemed necessary in 245 patients, of which 126 underwent an additional examination (51.4%). Radiology was the primary method used for complete colonic evaluation, whereas a repeat colonoscopy was performed in only 6.4%; the examination was normal in 119 patients (94.4%). A mucosal high-grade neoplasia was removed in 1, and multiple (≥3) adenomas were removed in 2 patients. The present screening programme with biennial faecal occult blood testing revealed a high colonoscopy completion rate, a low rate of secondary colonic evaluation, infrequent use of colonoscopy for completion, and a low detection rate of significant neoplasia. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.
    Digestive and Liver Disease 05/2015; DOI:10.1016/j.dld.2015.05.007 · 2.89 Impact Factor
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    ABSTRACT: The aim of this study was to estimate of the number of sudden cardiac deaths attributable to the use of domperidone in France in 2012 METHODS: Computation of the attributable fraction, function of the increase in risk of sudden cardiac death induced by domperidone and of the exposure prevalence. Multiplying the attributable fraction by the risk of sudden cardiac death in the French population gives an estimation of the number of sudden cardiac deaths attributable to domperidone. The use of domperidone in France is the cause of 231 deaths per year in the population aged 18 years or over. This risk should be taken into consideration by clinicians when prescribing a drug which provides a minor benefit. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 03/2015; 24(5). DOI:10.1002/pds.3771 · 3.17 Impact Factor
  • Endoscopy 02/2015; 47(03). DOI:10.1055/s-0035-1545391 · 5.20 Impact Factor
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    ABSTRACT: Measuring adenoma detection is a priority in the quality improvement process for colonoscopy. Our aim was (1) to determine the most appropriate quality indicators to assess the neoplasia yield of colonoscopy and (2) to establish benchmark rates for the French colorectal cancer screening programme. Retrospective study of all colonoscopies performed in average-risk asymptomatic people aged 50-74 years after a positive guaiac faecal occult blood test in eight administrative areas of the French population-based programme. We analysed 42,817 colonoscopies performed by 316 gastroenterologists. Endoscopists who had an adenoma detection rate around the benchmark of 35% had a mean number of adenomas per colonoscopy varying between 0.36 and 0.98. 13.9% of endoscopists had a mean number of adenomas above the benchmark of 0.6 and an adenoma detection rate below the benchmark of 35%, or inversely. Correlation was excellent between mean numbers of adenomas and polyps per colonoscopy (Pearson coefficient r=0.90, p<0.0001), better than correlation between mean number of adenomas and adenoma detection rate (r=0.84, p=0.01). The mean number of adenomas per procedure should become the gold standard to measure the neoplasia yield of colonoscopy. Benchmark could be established at 0.6 in the French programme.
    Digestive and Liver Disease 09/2013; 46(2). DOI:10.1016/j.dld.2013.08.129 · 2.89 Impact Factor
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    ABSTRACT: The aim of this study was to compare the performance of the guaiac-based faecal occult blood test (G-FOBT), with that of three immunochemical faecal occult blood tests (I-FOBT) which allow automatic interpretation. Under the French organised screening programme, 85,149 average-risk individuals aged 50-74 participating in the third screening round, performed both the G-FOBT (Hemoccult-II test) and one of the I-FOBTs: FOB-Gold, Magstream and OC-Sensor. Given the chosen threshold, the positivity ratio between the different I-FOBTs and the G-FOBT was 2.4 for FOB-Gold, 2.0 for Magstream and 2.2 for OC-Sensor (P=0.17). The three I-FOBTs were superior to the G-FOBT for colorectal cancer (CRC) detection. The ratios for detection rates were 1.6 (FOB-Gold), 1.7 (Magstream) and 2.1 (OC-Sensor) (P=0.74). For non-invasive CRC they were, respectively, 2.5, 3.0 and 4.0 (P=0.83) and for advanced adenomas 3.6, 3.1 and 4.0 (P=0.39). This study provides further evidence that I-FOBT is superior to G-FOBT. None of the three I-FOBTs studied appeared to be significantly better than the others.
    European journal of cancer (Oxford, England: 1990) 05/2012; 48(16):2969-76. DOI:10.1016/j.ejca.2012.04.007 · 4.82 Impact Factor
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    ABSTRACT: Measuring neoplasia yield is a priority in the quality improvement process for colonoscopy. However, neither the most appropriate quality indicator nor the standard threshold has been established. To determine the most appropriate quality indicators to assess the yield of routine colonoscopy. Retrospective. Population-based colorectal cancer screening program in 3 French administrative areas. One hundred gastroenterologists and their average-risk asymptomatic patients aged 50 to 74 years undergoing colonoscopy for positive guaiac-based fecal occult blood test results. Comparison of several indicators, mainly the adenoma detection rate (ADR) and polyp detection rate (PDR), the mean number of adenomas per colonoscopy (MNA) and mean number of polyps (MNP) and the proportion of adenomas among polyps (PAP). Correlations were good between the ADR and PDR (Pearson coefficient r = 0.88 [95% CI, 0.78-0.94]) and between MNA and MNP (r = 0.89 [95% CI, 0.79-0.94]) (P < .0001 for both). Gastroenterologists were classified as higher or lower detectors in comparison with the lower limit of the 95% confidence interval of the median value for each indicator. The MNP (MNA) provided better discrimination than the PDR (ADR). Concordance between classifications of gastroenterologists according to their MNA and MNP was excellent (κ = 0.89). PAP varied dramatically from 38% to 95% between gastroenterologists and was very poorly correlated with the ADR (r = -0.27 [95% CI, -0.54 to 0.07; P = .11]) and the MNA (r = 0.03 [95% CI, -0.29 to 0.36; P = .88]). Some factors influencing the neoplasia yield were not taken into account. The MNP could replace the ADR for the assessment of adenoma detection in routine practice. A separate indicator, PAP, would be necessary to assess adenoma discrimination ability.
    Gastrointestinal endoscopy 09/2011; 74(6):1325-36. DOI:10.1016/j.gie.2011.07.038 · 4.90 Impact Factor
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    ABSTRACT: The aim of this study was to define the positive predictive values of a positive guaiac faecal occult blood test according to the number of positive squares, in two consecutive rounds of colorectal cancer mass screening in a French region. A total of 4172 colonoscopies were analyzed. Sex, age, number of positive squares, and colonoscopic and histopathologic findings were studied. In the results obtained, 76.6% of positive tests were positive with one or two squares. The number of positive squares was not related to sex, age and rank of participation. The positive predictive value for cancers and adenomas increased significantly with age, sex (male) and number of positive squares from 6.6% (one to two squares) to 27.6% (five to six squares) and from 15.2% to 22.2%, respectively. Cancer was diagnosed 211 times (54.1%) and advanced neoplasia was diagnosed 696 times (65.3%) following positive tests with one to two squares. The TNM stage of cancer increased significantly with the number of positive squares: 85.8% of stages 0-1-2 for one to two positive squares and 66.3% for five to six positive squares (P<0.001). Multivariate analysis showed an increased risk of cancer and advanced neoplasia for male patients and aged persons. The number of positive squares significantly increased the risk of cancer (odds ratio=4.6 for five to six positive squares) and the risk of advanced neoplasia (odds ratio=2.9). Age, sex and number of positive squares were independent predictive factors of positive guaiac faecal occult blood test. The proportion of TNM stages 3-4 was significantly higher in those with five to six positive squares. Performing a complete colonoscopy in every individual having a positive test, especially aged men with a high number of positive squares, should be a priority in any screening programme.
    European journal of cancer prevention: the official journal of the European Cancer Prevention Organisation (ECP) 07/2011; 20(4):277-82. DOI:10.1097/CEJ.0b013e3283457290 · 2.76 Impact Factor
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    ABSTRACT: We previously showed a significant variability in adenoma detection among colonoscopists who were participating in a mass screening program. The reasons for such variability remain largely unknown. To study intercenter variations in neoplasia detection. Secondary analyses of colonoscopy findings from the 2 first rounds of a French screening program: logistic regressions and repeated-measures analyses of variance. A total of 3487 colonoscopies performed by all 19 endoscopists who performed 30 examinations or more per round at 8 centers (6 private, 2 public). Probabilities of detecting 1, 2, or 3 or more adenomas, 1 adenoma 10 mm or larger, or colorectal cancer, as well as the corresponding adjusted (for patient age and sex) per-center detection rates. Endoscopy centers were not significant predictors of the probability of detecting any category of neoplasia with the exception of the 2 adenomas or more category (P < .005). The ranges of the adjusted detection rates for each of these categories were 33.1% to 43.1%, 11.1% to 21.6%, 3.6% to 8.1%, 16.3% to 23.6%, and 8.3% to 12.6%, respectively. When the colonoscopies that were performed by the 11 endoscopists who performed 30 examinations or more per center in 2 or more centers were separately analyzed, no intercenter statistically significant variability was observed with the exception of 1 endoscopist and the 1 adenoma category. In a subgroup of 1100 colonoscopies performed by 6 endoscopists who were working at the same 3 centers, intercenter variability was not statistically significant. Type II error because of sample sizes. In our setting, intercenter variability did not explain interendoscopist variability for neoplasia detection rate.
    Gastrointestinal endoscopy 07/2011; 74(1):141-7. DOI:10.1016/j.gie.2011.03.1179 · 4.90 Impact Factor
  • Gastrointestinal Endoscopy 04/2011; 73(4). DOI:10.1016/j.gie.2011.03.975 · 4.90 Impact Factor
  • Endoscopy 03/2011; 43(03). DOI:10.1055/s-0031-1273152 · 5.20 Impact Factor
  • Gastroenterology 01/2011; 140(5). DOI:10.1016/S0016-5085(11)62351-2 · 13.93 Impact Factor
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    ABSTRACT: The aim was to determine the rate of high-grade dysplasia among patients with all adenomas, and its prevalence in patients with adenomas of different sizes in a well-defined population-based study. We performed a secondary analysis of the 2295 colonoscopies performed following a positive fecal occult blood test result during the first round of colorectal cancer screening in one French district. The rates of high-grade dysplasia were calculated for 3 size categories of adenoma (diminutive, <or=5 mm; small, 6-9 mm; large, >or=10 mm). Predictive factors for high-grade dysplasia were assessed by univariate and multivariate analyses. A total of 1284 adenomas were detected in 784 subjects. High-grade dysplasia was present in 32.1% of the 784 subjects and in 2.7%, 16.0%, and 51.1% of those whose adenomas were diminutive, small, and large, respectively. Among subjects with no more than 2 small adenomas, the proportion of those with high-grade dysplasia was 12.4%. Both adenoma size and a villous component within adenomas were found to be independent predictive factors for high-grade dysplasia by multivariate analysis. Because of the high rate of high-grade dysplasia among small adenomas, our results reinforce the need to remove all small adenomas detected at colonoscopy. Furthermore, the results suggest that opting for CT colonography surveillance instead of colonoscopic removal among subjects with one or 2 small polyps revealed by CT colonography would have led to missed high-grade dysplasia in 12.4% of them.
    Diseases of the Colon & Rectum 03/2010; 53(3):339-45. DOI:10.1007/DCR.0b013e3181c37f9c · 3.20 Impact Factor
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    ABSTRACT: There are few data about the performance variability among endoscopists participating to nationwide or regionwide colorectal cancer screening programs. To assess the variability of neoplasia detection rates among endoscopists participating in a regional colorectal cancer screening program based on colonoscopy after biennial fecal occult blood testing (FOBT). Two rounds of colonoscopy were performed: round 1 took place in 2003 and 2004, and round 2 took place in 2005 and 2006. Secondary analysis of colonoscopy findings from the first 2 rounds was performed by using data drawn from all endoscopists who performed more than 30 colonoscopies in each round. Detection rates were adjusted for patient age and sex, and logistic regression analyses were conducted including these 2 variables and round number (1 or 2). District of Ille-et-Vilaine in Brittany (population >900,000) between 2003 and 2007. The per-endoscopist adjusted rates of colonoscopies with at least 1, 2, or 3 adenomas, 1 adenoma 10 mm or larger, or a cancer. Among the 18 endoscopists who performed 3462 colonoscopies, the adjusted detection rates were in the following ranges: at least 1 adenoma, 25.4% to 46.8%; 2 adenomas, 5.1% to 21.7%; 3 adenomas, 2.7% to 12.4%; 1 adenoma 10 mm or larger, 14.2% to 28.0%; and cancer, 6.3% to 16.4%. Multivariate analyses showed that the endoscopist was not an independent predictor of cancer detection, but was an independent predictor of detecting adenomas, regardless of category; the R(2) of the models ranged from 6% to 13% only. Other factors known to influence colorectal neoplasia occurrence and withdrawal time could not be taken into account. In a screening program with a high compliance rate with colonoscopy after FOBT, interendoscopist variability had no effect on cancer detection, but did influence identification of adenomas. The clinical impact of such findings merits further evaluation.
    Gastrointestinal endoscopy 11/2009; 71(2):335-41. DOI:10.1016/j.gie.2009.08.032 · 4.90 Impact Factor
  • Gastroenterology 05/2009; 136(5). DOI:10.1016/S0016-5085(09)62870-5 · 13.93 Impact Factor
  • Revue d Épidémiologie et de Santé Publique 05/2009; 57. DOI:10.1016/j.respe.2009.02.106 · 0.66 Impact Factor
  • Gastrointestinal Endoscopy 04/2009; 69(5). DOI:10.1016/j.gie.2009.03.464 · 4.90 Impact Factor
  • Endoscopy 03/2009; 41(03). DOI:10.1055/s-0029-1215629 · 5.20 Impact Factor
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    ABSTRACT: But Les résultats du dépistage du cancer colorectal (CCR) au cours des campagnes (C) ultérieures à C1 ont été analysés sur la base de cohortes fixes dans les essais contrôlés publiés. Connaître les résultats de la vraie vie, à l’échelle d’une population par définition fluctuante, serait utile à une modélisation des résultats du dépistage organisé en France. Patients et Méthodes Nous avons comparé les resultants finalisés des 2 premières campagnes (C1 et C2) réalisées dans notre département : C1 en 2003-2004 (finalisation au 1.01.2006), C2 en 2005-2006 (finalisation au 1.01.2008). De plus, pour C2, nous avons comparé les résultats pour le groupe n’ayant jamais participé au dépistage (C2-1) à ceux des personnes invitées à renouveler le test (C2-2). Pour les lésions diagnostiquées par coloscopie, les résultats ont été exprimés en taux de détection per-protocole -TDPP- (rapports aux personnes ayant fait le test) et en intention de dépister -TDID- (rapportés à la population cible). Test de comparaison Chi2. Analyse multivariée par régression logistique. Résultats Les populations cibles de C1 et C2 étaient de 185 508 et 191 992 personnes, respectivement. Le taux de participation (TP) était de 52,1 % à C1 et 46,5 % à C2 (p < 105). Au sein de C2, les TP étaient de 23,9 % et 76 % pour C2-1 et C2-2. Au sein de C2- 1, les TP étaient de 39 % pour ceux invités pour la 1ère fois et de 19,5 % pour les non répondants à C1. Les taux de positivité du test étaient de 2,6 % à C1 et 2,26 % à C2 (- 0,34 %, p < 105). Les taux de suivi par coloscopie étaient respectivement de 92,6 % et 91,05 % (p < 0,05). La différence des VPP entre C1 et C2 était significative pour les CCR (-1,8 %, p < 0,05) et la somme adénomes (AD) + CCR (-3,2 %, p < 0,05). Les TDPP et TDID étaient significativement moins élevés pour C2 que C1 pour les CCR, les AD, les AD avancés et AD ≥ 10 mm. Pour chacune des lésions, la comparaison des groupes C2-1 et C2-2 montrait des VPP et TDPP significativement plus élevés pour C2-1 que C2-2, mais les resultants étaient inversés pour le TDID : CCR (0,05 vs 0,10, p < 105), AD (0,18 vs 0,40, p < 10−5). La VPP pour le diagnostic de CCR était significativement plus élevée pour C2-2 que C2-1 chez les individus ≥ 60 ans (13,4 % vs 9,4 %, p < 0,001) sans différence chez ceux < 60 ans (6,2 % vs 6 %, ns). La comparaison entre C1 et chacun des sous-groupes de C2 montrait que les TDID étaient très différents entre C1 et C2-1 (p < 10−7), mais semblables entre C1 et C2-2. Les résultats de l’analyse multivariée tenant compte de l’âge et du sexe des individus seront présentés lors du congrès. Conclusion Ces résultats montrent une moindre participation à C2 qu’à C1. Les résultats à C2 sont différents selon qu’il s’agit d’une 1ère (C2-1) ou 2ème (C2-2) participation. Malgré des taux de positivité et des VPP moins élevés à C2, les performances du dépistage, exprimées par les TDID, sont identiques pour le groupe invité à renouveler le test à celles enregistrées à C1. Il est regrettable qu’un quart de ces personnes ne participent pas à C2. Nos résultats soulignent aussi le rôle joué par l’âge et le sexe dans les résultats de C2.
    Gastroentérologie Clinique et Biologique 03/2009; 33(3). DOI:10.1016/S0399-8320(09)72647-8 · 1.14 Impact Factor
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    ABSTRACT: Mass screening for colorectal cancer in France was initiated in pilot regions on the basis of the fecal occult blood test (FOBT) followed by colonoscopy in positive cases. We report the colonoscopy results in one of the first areas to be screened (Ille et Vilaine). Of the total regional population of 908,449, 187,342 of the 213,635 potential screening candidates who were aged 50 - 74 years were invited for FOBT. Of the 51.3% compliant individuals, 2.6% were positive, and of these 90.7% agreed to undergo colonoscopy (n = 2246). The colonoscopy procedure details, findings, and complications were recorded. Subjects were classified according to the most advanced lesion. Positive predictive values of FOBT were calculated according to sex and age. Colonoscopy was complete in 96.3% of cases. Only 23 adverse events were encountered (1.02%). Colorectal cancer was diagnosed in 237 cases (10.6%, 78.4% of which were clinical stages I - II). The rates of overall adenomas and advanced adenomas were 33.1 % and 21.6 %, respectively. The risk of cancer and advanced adenoma increased significantly in men and in older people. The results of mass screening with FOBT followed by colonoscopy in this population-based study are very encouraging in terms of compliance, early findings, and complications. Extension of this program to the whole of France is justified.
    Endoscopy 06/2008; 40(5):422-7. DOI:10.1055/s-2007-995430 · 5.20 Impact Factor