Assessment of the multiple components of the variability in the adenoma detection rate in sigmoidoscopy screening, and lessons for training
ABSTRACT The determinants of the observed variability of adenoma detection rate (ADR) in endoscopy screening have not yet been fully explained.
Between November 1999 and November 2006 13 764 people (7094 men, 6670 women; age range 55-64) underwent screening flexible sigmoidoscopy at five hospital endoscopy units in Turin. To study the determinants of the ADR for distal adenomas, accounting for patient, examiner, and hospital characteristics, we applied a multivariate multilevel regression model.
Average ADRs for all adenomas and for advanced adenomas (size > or = 10 mm, villous component > 20 %, high grade dysplasia) were 13.5 % (range 5.2 %-25.0 %) and 6.4 % (3.1 %-10.7 %) for men, and 8.0 % (2.5 %-14.0 %) and 3.7 % (0.2 % - 7.4 %) for women. In multivariate analysis, increased ADR of advanced adenomas was associated with male gender (odds ratio [OR] 1.78, 95 %CI 1.49 - 2.11), self-report of one first-degree relative with colorectal cancer (CRC) (1.44, 1.11-1.86), or of recent-onset rectal bleeding (1.73, 1.24-2.40). Adjusting for these variables, a significantly lower ADR was found for endoscopists with either a lower rate of incomplete sigmoidoscopy (< 9 %; OR 0.59, 95 %CI 0.41-0.87) or a higher rate (> 12 %; 0.64, 0.45-0.91), or with low activity volume (< 85 sigmoidoscopies/year; 0.66, 0.50-0.86). Residual variability explained by the endoscopy center effect was about 1 % and statistically significant.
Endoscopist performance in flexible sigmoidoscopy CRC screening is highly variable. Low volume of screening activity independently predicts lower ADR, suggesting that operators devoting more time to screening sigmoidoscopy may perform better. Variability among pathologists in adenoma classification might explain part of the residual variability across endoscopy units.
- SourceAvailable from: Enrique Quintero
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- "These same efforts should however be implemented also for all the recommended screening methods. A wide variability in adenoma detection rate has been observed in the context of the trials and programs adopting FS [45–48] and also in the context of FOBT/FIT-based screening quality of laboratory procedures deserves adequate scrutiny. "
ABSTRACT: Although faecal and endoscopic tests appear to be effective in reducing colorectal cancer incidence and mortality, further technological and organizational advances are expected to improve the performance and acceptability of these tests. Several attempts to improve endoscopic technology have been made in order to improve the detection rate of neoplasia, especially in the proximal colon. Based on the latest evidence on the long-term efficacy of screening tests, new strategies including endoscopic and faecal modalities have also been proposed in order to improve participation and the diagnostic yield of programmatic screening. Overall, several factors in terms of both efficacy and costs of screening strategies, including the high cost of biological therapy for advanced colorectal cancer, are likely to affect the cost-effectiveness of CRC screening in the future.Gastroenterology Research and Practice 04/2012; 2012(1687-6121):846985. DOI:10.1155/2012/846985 · 1.75 Impact Factor
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- "The approach mediates reduction of the incidence and mortality of CRC [30,31], particularly of the left-sided tumors. Although a UK-based randomized study  showed reduction of mortality due to tumors anywhere in the colonic bowel, most studies have shown that transverse and right-sided lesions are missed [32-34] even when combined with a subsequent FOBT . These results plus those from a Norwegian study  raise the question of whether sigmoidoscopy should be recommended in place of colonoscopy for future screening procedures, or at least considered an option comparable to colonoscopy for individuals offered screening for CRC [35-37]. "
ABSTRACT: Emerging results indicate that screening improves survival of patients with colorectal cancer. Therefore, screening programs are already implemented or are being considered for implementation in Asia, Europe and North America. At present, a great variety of screening methods are available including colono- and sigmoidoscopy, CT- and MR-colonography, capsule endoscopy, DNA and occult blood in feces, and so on. The pros and cons of the various tests, including economic issues, are debated. Although a plethora of evaluated and validated tests even with high specificities and reasonable sensitivities are available, an international consensus on screening procedures is still not established. The rather limited compliance in present screening procedures is a significant drawback. Furthermore, some of the procedures are costly and, therefore, selection methods for these procedures are needed. Current research into improvements of screening for colorectal cancer includes blood-based biological markers, such as proteins, DNA and RNA in combination with various demographically and clinically parameters into a "risk assessment evaluation" (RAE) test. It is assumed that such a test may lead to higher acceptance among the screening populations, and thereby improve the compliances. Furthermore, the involvement of the media, including social media, may add even more individuals to the screening programs. Implementation of validated RAE and progressively improved screening methods may reform the cost/benefit of screening procedures for colorectal cancer. Therefore, results of present research, validating RAE tests, are awaited with interest.Scandinavian Journal of Gastroenterology 08/2011; 46(11):1283-94. DOI:10.3109/00365521.2011.610002 · 2.36 Impact Factor
Conference Paper: OFDM modem for ATM based point-multipoint systems[Show abstract] [Hide abstract]
ABSTRACT: In this paper an application of the OFDM modulation to the "last mile" problem and the main algorithms involved are described. Moreover, the architectures of the most important blocks (namely modulator and demodulator) are illustrated and the design methodology is described. The system has been simulated in FPL and FXP arithmetic and a VHDL description has been automatically generated by using COSSAP. Finally the architecture has been synthesized and mapped on FPGAs.Circuits and Systems for Communications, 2002. Proceedings. ICCSC '02. 1st IEEE International Conference on; 02/2002