Surveillance Interval (surveillance + interval)

Distribution by Scientific Domains


Selected Abstracts


Outcome of endoscopy surveillance for Barrett's oesophagus

ANZ JOURNAL OF SURGERY, Issue 11 2009
Tim Bright
Abstract Background:, Endoscopic surveillance of individuals with Barrett's oesophagus is undertaken to detect early stage oesophageal malignancy. The impact of a surveillance programme on endoscopy resources and disease detection is uncertain. Methods:, In 2004, we commenced a structured Barrett's oesophagus surveillance programme. The surveillance protocol specifies surveillance interval and number of oesophageal biopsies required according to previous endoscopy and biopsy findings. The first 3 years of surveillance were reviewed to assess programme adherence, impact on endoscopy resources and the incidence of high-grade dysplasia and adenocarcinoma in patients undergoing surveillance. Results:, Four hundred five patients were enrolled in the surveillance programme, and 776 patient years of endoscopy follow-up were analysed. Four-quadrant biopsies every 2 cm throughout the Barrett's oesophagus were performed in 89.8% of endoscopies. A total of 93.7% of patients had surveillance endoscopy performed at the appropriate time interval. Formalizing surveillance was followed by a decrease in the mean time interval for endoscopy surveillance from 16 months to 15 months, although the mode endoscopy surveillance interval lengthened from 1 year to 2 years. The mean number of biopsies per endoscopy increased from 5.9 to 7. In four patients, T1 stage oesophageal adenocarcinoma was identified, and in six patients, high-grade dysplasia was identified (combined incidence of adenocarcinoma/high-grade dysplasia 1 per 77.6 endoscopy years of follow-up). Conclusions:, Structured Barrett's surveillance detects malignant progression at an early stage, which provides opportunities for curative surgical or endoscopic intervention. Formalizing surveillance resulted in a high rate of adherence to agreed guidelines and rationalized the use of endoscopy resources without significantly increasing workload. [source]


Growth rates of small abdominal aortic aneurysms correlate with clinical events

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 1 2010
A. R. Thompson
Background: This retrospective analysis of prospectively collected abdominal aortic aneurysm (AAA) screening data aimed to identify predictors of AAA-related events (surgery or death) with a view to better targeting of screening. Methods: For the interval 1984,2007, data for 1649 subjects with an AAA were collected prospectively as part of the Chichester AAA screening programme. This included serial aortic size measurements, blood pressure, risk factors for arterial disease and concurrent medications. AAA growth rates were adjusted for risk factor confounders using flexible hierarchical modelling. AAA growth distribution was analysed using Silverman's test of multimodality. Results: Some 1231 subjects met the inclusion criteria of having more than one scan and a surveillance interval of over 3 months. AAA growth showed a bimodal pattern with nearly 50 per cent of all aneurysms never progressing to surgery or rupture. Adjusted annual AAA growth rates of at least 2 mm significantly predicted AAA-related events. Conclusion: This analysis identified a bimodal growth pattern for AAA, with a significant association between annual AAA growth rate of at least 2 mm and AAA-related events. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]


Sequential case series analysis for pharmacovigilance

JOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2009
Mounia N. Hocine
Summary., The self-controlled case series method is used to evaluate drug safety, particularly the safety of paediatric vaccines with respect to rare adverse reactions. We propose a group sequential version of the method for prospective surveillance of drug safety. We focus on the surveillance of new vaccines. We develop methods that are based on the sequential probability ratio test applied at predetermined surveillance intervals, using both simple and composite alternative hypotheses. We investigate the properties of the methods analytically in a simple setting and by simulations in more realistic scenarios. The methods are applied to data on influenza vaccine and Bell's palsy, and to data on measles, mumps and rubella vaccine and bleeding disorders. [source]