Switching from guaiac to immunochemical faecal occult blood test increases participation and diagnostic yield of colorectal cancer screening.

BACKGROUND: Compared with the guaiac-faecal occult blood test (gFOBT), faecal immunological tests (FIT) are considered to be more effective for colorectal cancer (CRC) screening. However, only scarce research has examined the outcomes of switching to FIT within a mature gFOBT-based CRC screening programme. METHODS: We reported a 15-year experience of biennial FOBT screening in a well-defined population of approximately one million inhabitants, including six gFOBT-based screening rounds and one round with FIT at the 30 µg Hb/g cut-off. The main outcome measures were screening participation, FOBT positivity and advanced neoplasia detection in each round. RESULTS: In this study, 647 676 screenings were performed in 228 716 different individuals, leading to 17 819 positives and 16 580 follow-up colonoscopies. Compared with the last gFOBT round, switching to FIT led to an increased participation of nearly 20% points, and a fivefold increased detection of CRC and advanced adenoma among invitees (3-fold among attendees). The numbers needed to screen and scope to detect one advanced neoplasia declined from 221 to 66 and from 4.7 to 2.6, respectively. CONCLUSIONS: The present population-based study demonstrated a dramatical increase in the diagnostic yield of advanced neoplasia by switching to FIT within a mature gFOBT-based CRC screening programme.

Additional mailing phase for FIT after a medical offer phase: The best way to improve compliance with colorectal cancer screening in France.

BACKGROUND: Compliance with colorectal cancer screening is critical to its effectiveness. The organisation of the mass screening programme in France has recently been modified with no evaluation of the consequences. AIMS: To evaluate the impact of the way the screening test is delivered on compliance. PATIENTS AND METHODS: During the first six months of the screening campaign (Ille-Vilaine, Brittany), general practitioners were asked to propose a faecal immunochemical test (FIT), OC-Sensor, to individuals at average risk for colorectal cancer (n=152,097). A subset of non-participants in the medical phase (n=13,071) was randomly chosen to receive a reminder that included the screening test or a simple postal reminder without the screening test. RESULTS: Compliance was 31% if the screening test was proposed during a medical consultation. In non-participants during the medical phase, it was 45% in those receiving both a reminder and the screening test and 28% amongst those receiving a simple reminder. An estimated overall participation rate of 54% can be expected if non-participants in the medical phase are sent a reminder together with the screening test. CONCLUSION: In France, a compliance rate above the minimum uptake rate of 45% recommended by European Union experts can be achieved if the FIT is mailed to non-participants after the medical free-offer phase.

Estimating the number of sudden cardiac deaths attributable to the use of domperidone in France.

PURPOSE: 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. RESULTS: The use of domperidone in France is the cause of 231 deaths per year in the population aged 18 years or over. CONCLUSIONS: This risk should be taken into consideration by clinicians when prescribing a drug which provides a minor benefit.

The cost-effectiveness of immunochemical tests for colorectal cancer screening.

BACKGROUND: The optimal immunochemical test to use for generalised mass screening is still under debate in France. AIM: To compare the cost and effectiveness in biennial screening for colorectal cancer of fifteen strategies consisting of the three-stool sample un-rehydrated guaiac faecal occult blood test and three immunochemical tests: Magstream, FOB-Gold and OC-Sensor, at different positivity cut-off levels and stool-sample collection. METHODS: A Markov model was used to compare these strategies in a general population of 100,000 individuals aged 50-74 over a 20-year period. RESULTS: Immunochemical tests were efficient strategies compared with guaiac faecal occult blood test. When all 15 strategies were compared with each other, only five of them remained efficient: the one- and two-stool sample Magstream, the one- and two-stool sample FOB-Gold with the 176 ng/mL cut-off, and the two-stool sample OC-Sensor with the 150 ng/mL cut-off. Sensitivity analyses showed that, at an identical price, the one-stool sample OC-Sensor was the most efficient strategy, and outperformed FOB-Gold. CONCLUSION: One-stool immunochemical testing can be considered a promising alternative to the guaiac faecal occult blood test for colorectal cancer mass screening in the general population. Competition between manufacturers should now be introduced to reduce purchase price differences.

Positivity rates and performances of immunochemical faecal occult blood tests at different cut-off levels within a colorectal cancer screening programme.

BACKGROUND: Immunochemical faecal occult blood tests have greater sensitivity for colorectal cancer screening than guaiac-based tests; however the number of positive tests required is still under discussion. METHODS: A direct comparison of Hemoccult II with two immunochemical quantitative tests (OC-Sensor and FOB-Gold) using a 2-sample strategy was performed in over 30,000 patients undergoing colorectal cancer screening in France. RESULTS: Positivity ratio between immunochemical tests and Hemoccult II varied between 2.2 (OC-Sensor) and 2.4 (FOB-Gold) for the lowest cut-off value and 1.5-1.4 for the highest cut-off value. The positive predictive value for colorectal cancer was similar for immunochemical tests and Hemoccult II, and significantly higher for immunochemical tests for advanced adenomas. The detection rate of both colorectal cancer and advanced adenomas was higher with immunochemical tests than with Hemoccult II. With the 2-sample strategy and the lowest cut-off value the detection rate of colorectal cancer almost doubled and for advanced adenomas quadrupled. CONCLUSION: For colorectal cancer screening with immunochemical faecal occult blood tests, an acceptable strategy would be 2-day sampling with at least one positive test at a cut-off between 150 and 200 ng/mL (OC-Sensor) and 176 and 234 ng/mL (FOB-Gold). Data on the ease of test interpretation and cost-effectiveness now necessary to make definitive choices.

The positive predictive value of guaiac faecal occult blood test in relation to the number of positive squares in two consecutive rounds of colorectal cancer screening.

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.

Neoplasia detection rates after positive fecal occult blood test results are not affected by endoscopy center: a population-based study.

BACKGROUND: 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. OBJECTIVE: To study intercenter variations in neoplasia detection. DESIGN AND SETTING: Secondary analyses of colonoscopy findings from the 2 first rounds of a French screening program: logistic regressions and repeated-measures analyses of variance. MATERIAL: 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). MAIN OUTCOME MEASUREMENTS: 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. RESULTS: 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. LIMITATIONS: Type II error because of sample sizes. CONCLUSIONS: In our setting, intercenter variability did not explain interendoscopist variability for neoplasia detection rate.

A comprehensive theoretical investigation of the electronic states of Ca2 up to the Ca(4s(2) 1S) + Ca(4s5p 1P) dissociation limit.

A theoretical survey of the electronic structure of Ca(2) is presented using two-electron pseudopotentials complemented by core-polarization operators on Ca atoms and multireference configuration interaction/quasidegenerate perturbation theory (MRCI/QDPT) treatment of molecular excited states. The spectroscopic constants of 70 electronic states up to 30,000 cm(-1) above the ground state are determined. This implies all Ca(2) states dissociating up to the Ca(4s(2) (1)S) + Ca(4s5p (3,1)P) dissociation limits. All spin states (singlet, triplet, and quintet) are investigated. The work emphasizes the variety of interactions implying singly valence and lowest Rydberg excited states, doubly excited states generated by atom pairs (3)P(4s4p) + (3)P(4s4p), or (3)P(4s4p) + (3)D(4s3d), 4p3d double excitations asymptotically localized on a single-atom. Zwitterionic Ca(+) + Ca(-) configurations are evidenced and shown to induce specific electronic patterns in (1)Σ(g)(+), (3)Σ(g)(+), (1)Σ(u)(+), (3)Σ(u)(+), (1)Π(g), (3)Π(g), (1)Π(u), and (3)Π(u) symmetry manifolds. They also provide insight for qualitative features (barriers) found for the lower electronic states already investigated in previous publications by other authors.

Yield of high-grade dysplasia based on polyp size detected at colonoscopy: a series of 2295 examinations following a positive fecal occult blood test in a population-based study.

PURPOSE: 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. POPULATION AND METHODS: 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=10 mm). Predictive factors for high-grade dysplasia were assessed by univariate and multivariate analyses. RESULTS: 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. CONCLUSIONS: 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.

Variations between endoscopists in rates of detection of colorectal neoplasia and their impact on a regional screening program based on colonoscopy after fecal occult blood testing.

BACKGROUND: There are few data about the performance variability among endoscopists participating to nationwide or regionwide colorectal cancer screening programs. OBJECTIVE: 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). DESIGN: 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). SETTING: District of Ille-et-Vilaine in Brittany (population >900,000) between 2003 and 2007. MAIN OUTCOME MEASUREMENTS: The per-endoscopist adjusted rates of colonoscopies with at least 1, 2, or 3 adenomas, 1 adenoma 10 mm or larger, or a cancer. RESULTS: 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. LIMITATIONS: Other factors known to influence colorectal neoplasia occurrence and withdrawal time could not be taken into account. CONCLUSIONS: 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.

Simulation comparison of aircraft landing performance in foggy conditions aided by different UV sensors.

In the atmosphere pointlike sources are surrounded by an aureole due to molecular and aerosol scattering. UV phase functions of haze droplets have a very important forward peak that limits signal angular spreading in relation to the clear atmosphere case where Rayleigh scattering predominates. This specific property can be exploited using solar blind UV source detection as an aircraft landing aid under foggy conditions. Two methods have been used to compute UV light propagation, based on the Monte Carlo technique and a semi-empirical approach. Results obtained after addition of three types of sensor and UV runway light models show that an important improvement in landing conditions during foggy weather could be achieved by use of a solar blind UV intensified CCD camera with two stages of microchannel plates.

Results of a 12-month quality-circle prescribing improvement programme for GPs.

BACKGROUND: The impact of a quality-circle GP prescribing improvement programme, implemented in France in 2001-2002, was assessed by a controlled study. The study involved all 27 GPs of three semi-rural areas of Brittany, France. Practice data (overall prescribing cost and markers of prescribing efficiency) were collated in an intention-to-treat analysis, using the Mann-Whitney U test. Twenty-four GPs attended the meetings regularly. The reduction in drug expenditure exceeded the cost of the programme, although variations in size effects were observed among the settings.

Ultraviolet light propagation under low visibility atmospheric conditions and its application to aircraft landing aid.

Light scattering in the atmosphere by particles and molecules gives rise to an aureole surrounding the source image that tends to reduce the contrast of the source with respect to the background. However, UV scattering phase functions of the haze droplets present a very important forward peak. The spreading of a detected signal in the UV is not as important as in the case of a clear atmosphere where Rayleigh scattering predominates. This physical property has to be taken into account to evaluate the potential of UV radiation as an aircraft landing aid under low visibility conditions. Different results characterizing UV runway lights, simulations of UV radiation propagation in the atmosphere, and the use of a simple detection algorithm applied to one particular sensor are presented.