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Geoffrey M Forbes

Publications and source records attributed to Geoffrey M Forbes.

11 recordsLinked to original sources
PubMed2004

Influences on participation in a community-based colorectal neoplasia screening program by virtual colonoscopy in Australia.

OBJECTIVE: To determine the effect of certain personal and health behaviour characteristics on participation in a community-based colorectal neoplasia (CRN) screening program using virtual colonoscopy. METHODS: The study population comprised randomly selected subjects from the State electoral roll; screening by virtual colonoscopy was offered through letter of invitation. For non-responders, a further invitation was sent a month later. Non-response after a further month led to subjects being considered non-participants. Non-participants were contacted by letter to complete a structured questionnaire; participants completed a similar questionnaire immediately after their screening virtual colonoscopy. RESULTS: Discussing the invitation to screening with someone else increased the likelihood of participation by 63% (prevalence ratio 1.63, 95% CI 1.38-1.93); knowing someone with cancer increased the likelihood of participation by 23% (PR 1.23, 95% CI 1.07-1.42). Among participants who discussed screening with another individual, the spouse was the most common (71%). Subjects who were single were less likely to participate (PR 0.79, 95% CI 0.67-0.94). The strongest reported influence for participation was information provided in the letter of invitation (29.8%). The most common reasons for non-participation were lack of time and perceived good health. CONCLUSIONS AND IMPLICATIONS: This study suggests that a simple strategy to facilitate participation is to encourage subjects to discuss screening with others; further, to recognise that this may be most difficult for those who are single. Information provided to subjects prior to screening positively contributes to participation.

Colonoscopy↗
PubMed2004

Community-based screening by colonoscopy or computed tomographic colonography in asymptomatic average-risk subjects.

OBJECTIVES: Visualizing the entire colorectum in screening is an advantage of colonoscopy, and also computed tomographic (CT) colonography, another potentially suitable screening test. Our objective was to compare screening CT colonography and colonoscopy in an asymptomatic average-risk population, and to determine whether providing a choice of tests increased participation. METHODS: One thousand and four hundred subjects from the general community, randomly selected from the parliamentary electoral roll, were allocated one of three screening groups: colonoscopy, CT colonography, or a choice of these tests, and were sent an institutional letter of invitation. Those with symptoms, colorectal cancer in first-degree relatives, or colonoscopy within 5 yr were ineligible. Outcome measures were participation, acceptability of screening, and yield for advanced colorectal neoplasia in participants. RESULTS: Of the subjects, 24.9% were ineligible; the overall participation rate was 18.2% (184/1,009). Participation in each screening group was not different. Both tests were accompanied by the same high levels of acceptability; most participants found colonoscopy (87%) and CT colonography (67%, p < 0.001) less unpleasant than expected. About 29% (26/89) CT colonography subjects had a positive screening test. The yield of advanced colorectal neoplasia was 8.7% (95% CI 5-14%), with no difference in yield between tests. CONCLUSION: Colorectal neoplasia screening by colonoscopy or CT colonography was associated with modest participation, high levels of acceptability, and similar yield for advanced colorectal neoplasia. Providing a choice of test did not increase participation.

Age Distribution↗
PubMed2003

Colorectal neoplasia screening with CT colonography in average-risk asymptomatic subjects: community-based study.

PURPOSE: To evaluate computed tomographic (CT) colonography as a screening tool for average-risk asymptomatic subjects with regard to participation, acceptability, and safety. MATERIALS AND METHODS: CT colonography for colorectal neoplasia screening was offered to 2,000 subjects aged 50-54 and 65-69 years. Only asymptomatic subjects at average risk of colorectal neoplasia were enrolled. Participants underwent CT colonography followed by colonoscopy if CT colonography findings showed any polyps. Acceptability was measured with a 100-point (0, most favorable; 100, least favorable) visual analogue scale (VAS). Chi2 statistic was used to compare participation rates among subgroups. Safety of CT colonography was evaluated by recording all important adverse events. RESULTS: A total of 1,452 subjects were eligible for screening. The adjusted participation rate was 28.4%. Participation was higher in younger subjects and in those from a high socioeconomic region. Major reasons for nonparticipation were insufficient time and perceived good health. Median VAS scores for pain, general satisfaction, embarrassment, and willingness to repeat screening were 13, 6, 8, and 5, respectively. Most subjects found CT colonography better than (60%) or same as (32%) expected. Ninety-three (27.4%) of 340 subjects were referred for colonoscopy, with polyps found in 67 (positive predictive value, 0.73). By adopting criteria that a positive finding at CT colonography is that of a single polyp larger than 5 mm or multiple polyps larger than 2 mm, 14% of CT examinations would have led to colonoscopy; 5.7% of CT findings were false-positive, with no significant impairment in large polyp detection. There were no important adverse events related to CT colonography, although four subjects had syncope or presyncope related to bowel preparation. CONCLUSION: Community-based colorectal neoplasia screening with CT colonography was accompanied by a participation rate that compares favorably with that of similar screening programs. CT colonography was highly acceptable to participants.

Aged↗
PubMed2002

Bacteria-free rinse water for endoscope disinfection.

BACKGROUND: Most breaches of endoscope disinfection result from inadequate manual cleaning or improper use of disinfectants. This is a description of how a quality assurance program identified rinse water as a source of bacterial contamination and how it facilitated the introduction of a novel means of delivering rinse water of high purity. METHODS: Between 1996 and 2001, weekly samples were obtained from accessory and suction channels of endoscopes as well as the internal chambers of automated washing machines. Samples were processed for routine bacterial and mycobacterial culture. RESULTS: Bacteria were isolated in 8.7% of samples collected between 1996 and 1998. Of 36 positive samples, 20 (54%) were Pseudomonas sp. Analysis of rinse water from pipework downstream from filters demonstrated high growth of Pseudomonas sp, suggesting biofilm within piping was contaminating rinse water. A system of hot water flushing of pipework was developed that maintains a temperature above 60 degrees C for 60 minutes on a daily basis. This resulted in a consistently low level of bacterial contamination. CONCLUSION: This report demonstrates the value of a quality assurance program for endoscope disinfection and shows how rinse water may contaminate disinfected endoscopes. A system of hot water purging of the rinse water delivery system markedly reduces this contamination.

Bacteria↗
PubMed2002

Computed tomography colonography (virtual colonoscopy): review.

Computed tomography examination of the colon performed after bowel cleansing and distension of the lumen with gas goes by several different names--CT colonography (CTC) and CT colography perhaps being the most common. Strictly, the term 'virtual colonoscopy' (VC), should be reserved for the process of examining 3-D, simulated endoluminal images with a capability to navigate through the bowel using appropriate software. Computed tomography colonography appears to be the name that has gained favour among radiologists, although it is suspected that 'virtual colonoscopy' will persist as a generic term due to its attractive 'high-tech' connotations for non-radiological medical and lay persons. Whatever the name, the technique has been made possible through the advent of fast helical CT scanners which allow acquisition of a volume of data, and of proprietary software which enables multiplanar reformatting and 3-D endoluminal reconstructions. It is evident that if CTC/VC can be shown to be acceptable to patients, safe, affordable and accurate, it has enormous potential as a diagnostic and screening tool for colorectal neoplasia.

Colon↗
PubMed2002

Proteome analysis of highly immunoreactive proteins of Helicobacter pylori.

BACKGROUND: Identification of the immunoreactive proteins of Helicobacter pylori is important for the development of both diagnostic tests and vaccines relating to the organism. Our aim was to determine whether there are significant differences between human IgG and IgA reactivities to individual H. pylori proteins, and whether patterns of immunoreactivity are sustained across different strains of H. pylori. METHOD: The total complement of protein from seven strains of H. pylori was resolved by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Proteins were transferred electrophoretically onto polyvinylene difluoride (PVDF) membranes, which were probed with sera pooled either from H. pylori-infected patients, or noninfected (control) patients. Highly immunoreactive proteins were detected using chromogenic enzyme-antibody conjugates recognising either serum IgG or IgA. These proteins were then characterised by tryptic peptide-mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). RESULTS: Highly immunoreactive proteins were detected which were common to all seven strains, and recognised by both immunoglobulin subclasses. The proteins appear to be localised in five groups. Protein analysis established that these groups encompass multiple isoforms of chaperonin HspB (two subgroups); urease beta-subunit UreB; elongation factor EF-Tu; and flagellin FlaA. The pattern of highly immunoreactive proteins was strongly conserved across the seven strains. CONCLUSION: These results suggest that within a tightly defined region on the H. pylori proteome map there are five groups of proteins that are highly reactive to both IgG and IgA. Our analysis suggests it is unlikely that the highly immunoreactive clusters harbour any significant proteins other than isoforms of HspB, UreB, EF-Tu and FlaA, and that, with the partial exception of FlaA, these clusters are strongly conserved across all seven strains.

Bacterial Proteins↗
PubMed2002

A randomized comparison of quadruple and triple therapies for Helicobacter pylori eradication: The QUADRATE Study.

BACKGROUND & AIMS: Direct comparisons of bismuth and proton pump inhibitor (PPI)-based triple and quadruple therapies for Helicobacter pylori eradication are lacking. To address this, a randomized study was conducted. METHODS: Infected dyspeptic patients received pantoprazole 40 mg, amoxicillin 1000 mg, and clarithromycin 500 mg, all twice daily, for 7 days (PAC7); or pantoprazole 40 mg twice daily, bismuth subcitrate 108 mg, and tetracycline 500 mg, both 4 times daily, and metronidazole 200 mg 3 times daily and 400 mg at night for 7 days (PBTM7); bismuth subcitrate 108 mg and tetracycline 500 mg, both 4 times daily, and metronidazole 200 mg 3 times daily and 400 mg at night for 14 days (BTM14). Outcome was assessed with (13)C-urea breath test. RESULTS: Eradication rates (intention to treat [n = 405]/per protocol [n = 320]) were similar for PAC7 (78%/82%) and PBTM7 (82%/88%); the latter significantly superior to BTM14 (69%/74%; P < 0.01). Pretreatment metronidazole resistance (MR) was 53% and clarithromycin resistance was 8%. Eradication rates for primary metronidazole sensitive/resistant isolates were 74%/87% with PAC7 and 80%/81% for PBTM7, compared with 76%/55% (P < 0.02) for BTM14. Noncompliance was greater with BTM14 (15%; P < 0.001) than PAC7 (3%) or PBTM7 (6%). Moderate-severe adverse events were more common with BTM14 (45%; P < 0.001), than PAC7 (23%) or PBTM7 (25%) with more discontinuations (9%, 2%, 3%, respectively). CONCLUSIONS: One-week PPI triple therapy is well tolerated and effective. The addition of PPI to bismuth triple therapy allows reduction of treatment duration with improved efficacy and tolerability, despite a high rate of MR. Quadruple therapy appears to overcome pretreatment MR in most cases. Two-week bismuth triple therapy is significantly inferior to quadruple therapy and less well tolerated than both 1-week therapies.

Adult↗