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1.  13C urea breath test for Helicobacter pylori: Evaluation of 10-minute breath collection 
To determine whether a shortened 13C urea breath test (13C UBT) (breath collection time of 10 min) is as reliable as the standard assay (30 min).
Two hundred ninety-seven patients (mean ± SD: 53±16 years, 57% female) completed a 13C UBT. Breath samples were obtained at baseline and at 5 min intervals up to 30 min. Sixty-seven patients also underwent endoscopic biopsy. Cluster analysis was performed on the 13C UBT data to determine the optimal cut-off point at each time interval. Sensitivity and specificity of the 13C UBT at all intervals compared with histology and culture and against the standard 30 min interval were determined.
The calculated optimal cut-off points for each time interval (T), expressed as delta over baseline (δ‰), were 3.29 δ‰ at T5, 3.15 δ‰ at T10, 3.42 δ‰ at T15, 3.17 δ‰ at T20, 2.99 δ‰ at T25 and 2.82 δ ‰ at T30. Except at T5, the risk of false-positive and false-negative test results at each time interval was lower than 2.3% using these cut-off points. When replacing the cut-off points with 3.0 δ‰, the risk of error was still lower than 2.3%. The test at T10 showed 98.6% sensitivity and 98.6% specificity compared with T30. T10 and T30 showed 100% sensitivity and 96% specificity compared with histology and culture.
The 13C UBT is an accurate, noninvasive test, even when the breath sample interval is reduced to 10 min. The present study confirms the validity of a cut-off point of 3.0 δ‰ for the 10 min and 30 min 13C UBT.
PMCID: PMC2660834  PMID: 17171196
13C urea breath test; Cut-off point; Helicobacter pylori
2.  13C urea breath test for Helicobacter pylori: Determination of the optimal cut-off point in a Canadian community population 
To determine the test characteristics and the optimal cut-off point for the 13C urea breath test (13C UBT) in a Canadian community laboratory setting.
Of 2232 patients (mean age ± SD: 51±21 years, 56% female) who completed a 13C UBT, 1209 were tested to evaluate the primary diagnosis of Helicobacter pylori infection and 1023 were tested for confirmation of eradication following treatment. Cluster analysis was performed on the 13C UBT data to determine the optimal cut-off point and the risk of false-positive and false-negative results. Additionally, 176 patients underwent endoscopic biopsy to allow validation of the sensitivity and specificity of the 13C UBT against histology and microbiology using the calculated cut-off point.
The calculated cut-off points were 3.09 δ‰ for the whole study population (n=2232), 3.09 δ‰ for the diagnosis group (n=1209) and 2.88 δ‰ for the post-treatment group (n=1023). When replacing the calculated cut-off points by a practical cut-off point of 3.0 δ‰, the risk of false-positive and false-negative results was lower than 2.3%. The 13C UBT showed 100% sensitivity and 98.5% specificity compared with histology and microbiology (n=176) for the diagnosis of active H pylori infection.
The 13C UBT is an accurate, noninvasive test for the diagnosis of H pylori infection and for confirmation of cure after eradication therapy. The present study confirms the validity of a cutoff point of 3.0 δ‰ for the 13C UBT when used in a large Canadian community population according to a standard protocol.
PMCID: PMC2660833  PMID: 17171195
13C urea breath test; Cut-off point; Helicobacter pylori
3.  Practice Audit in Gastroenterology (PAGE) program: A novel approach to continuing professional development 
Practice audit is an important component of continuing professional development that may more readily be undertaken if it were less complex. This qualitative study assessed the use of personal digital assistants to facilitate data collection and review.
Personal digital assistants programmed with standard questionnaires related to upper gastrointestinal endoscopies (Practice Audit in Gastroenterology-Endoscopy [‘PAGE-Endo’]) and colonoscopies (PAGE-Colonoscopy [‘PAGE-Colo’]) were provided to Canadian gastroenterologists, surgeons and internists. Over a three-week audit period, participants recorded indications, and the expected (E) and reported (R) findings for each procedure. Thereafter, participants recorded compliance with reporting, the ease of use and value of the PAGE program, and their willingness to perform another audit.
Over 15 to 18 months, 173 participants completed PAGE-Endo (6168 procedures) and 111 completed PAGE-Colo (4776 procedures). Most respondents noted that PAGE was easy to use (99%), beneficial (88% to 95%), and that they were willing undertake another audit (92% to 95%). In PAGE-Endo, alarm features were prevalent (55%), but major reported findings were less common than expected: esophagitis (E 29.9%, R 14.8%), esophageal stricture (E 8.3%, R 3.6%), gastric ulcer (E 17.0%, R 4.7%), gastric cancer (E 4.3%, R 1.0%) and duodenal ulcer (E 11.5%, R 5.7%). In PAGE-Colo, more colonoscopies were performed for symptom investigation (55%) than for screening (25%) or surveillance (20%). There were marked interprovincial variations with respect to sedation, biopsies and technical aspects of colonoscopy.
Secure, real-time data entry with review of aggregate and individual data in the PAGE program provided an acceptable, straightforward methodology for accredited practice audit activities. PAGE has considerable potential for continuing professional development in gastroenterology and other specialties.
PMCID: PMC2659923  PMID: 16779458
Colonoscopy; Continuing medical education; Continuing professional development; Endoscopy; Gastroenterology; Maintenance of certification; Personal digital assistant; Practice audit
4.  Validation of the Rockall scoring system for outcomes from non-variceal upper gastrointestinal bleeding in a Canadian setting 
AIM: To validate the Rockall scoring system for predicting outcomes of rebleeding, and the need for a surgical procedure and death.
METHODS: We used data extracted from the Registry of Upper Gastrointestinal Bleeding and Endoscopy including information of 1869 patients with non-variceal upper gastrointestinal bleeding treated in Canadian hospitals. Risk scores were calculated and used to classify patients based on outcomes. For each outcome, we used χ2 goodness-of-fit tests to assess the degree of calibration, and built receiver operating characteristic curves and calculated the area under the curve (AUC) to evaluate the discriminative ability of the scoring system.
RESULTS: For rebleeding, the χ2 goodness-of-fit test indicated an acceptable fit for the model [χ2 (8) = 12.83, P = 0.12]. For surgical procedures [χ2 (8) = 5.3, P = 0.73] and death [χ2 (8) = 3.78, P = 0.88], the tests showed solid correspondence between observed proportions and predicted probabilities. The AUC was 0.59 (95% CI: 0.55-0.62) for the outcome of rebleeding and 0.60 (95% CI: 0.54-0.67) for surgical procedures, representing a poor discriminative ability of the scoring system. For the outcome of death, the AUC was 0.73 (95% CI: 0.69-0.78), indicating an acceptable discriminative ability.
CONCLUSION: The Rockall scoring system provides an acceptable tool to predict death, but performs poorly for endpoints of rebleeding and surgical procedures.
PMCID: PMC4087542  PMID: 17203520
Upper gastrointestinal bleeding; Nonvariceal; Predictors; Rockall; Outcomes
5.  The relationship between general practice characteristics and quality of care: a national survey of quality indicators used in the UK Quality and Outcomes Framework, 2004–5 
BMC Family Practice  2006;7:68.
The descriptive information now available for primary care in the UK is unique in international terms. Under the 'Quality and Outcomes Framework' (QOF), data for 147 performance indicators are available for each general practice. We aimed to determine the relationship between the quality of primary care, as judged by the total QOF score, social deprivation and practice characteristics.
We obtained QOF data for each practice in England and linked these with census derived data (deprivation indices and proportion of patients born in a developing country). Characteristics of practices were also obtained. QOF and census data were available for 8480 practices.
The median QOF score was 999.7 out of a possible maximum of 1050 points. Three characteristics were independently associated with higher QOF scores: training practices, group practices and practices in less socially deprived areas. In a regression model, these three factors explained 14.6% of the variation in QOF score. Higher list sizes per GP, turnover of registered patients, chronic disease prevalence, proportions of elderly patients or patients born in a developing country did not contribute to lower QOF scores in the final model.
Socially deprived areas experience a lower quality of primary care, as judged by QOF scores. Social deprivation itself is an independent predictor of lower quality. Training and group practices are independent predictors of higher quality but these types of practices are less well represented in socially deprived areas.
PMCID: PMC1647283  PMID: 17096861

Results 1-5 (5)