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CONTEXT: Acute onset of monocular floaters and/or flashes represents a common presentation to primary care physicians, and the most likely diagnosis is posterior vitreous detachment (PVD). A significant proportion of patients with acute PVD develop an associated retinal tear that can lead to retinal detachment and permanent vision loss if left untreated. OBJECTIVE: To quantify the association between relevant clinical variables and risk of retinal tear in patients presenting with acute-onset floaters and/or flashes and PVD. DATA SOURCES: Structured MEDLINE (January 1950-September 2009) and EMBASE (January 1980-September 2009) searches and a hand search of references and citations of retrieved articles yielded 17 relevant studies. STUDY SELECTION: Studies of high-level methods that related elements of the history or physical examination in patients presenting with floaters and/or flashes and PVD to the likelihood of retinal tear. RESULTS: For patients with acute onset of floaters and/or flashes who are self-referred or referred to an ophthalmologist, the prevalence of retinal tear is 14% (95% confidence interval [CI], 12%-16%). Subjective visual reduction is the most important symptom associated with retinal tear (likelihood ratio [LR], 5.0; 95% CI, 3.1-8.1). Vitreous hemorrhage on slitlamp biomicroscopy is the best-studied finding with the narrowest positive LR for retinal tear (summary LR, 10; 95% CI, 5.1-20). Absence of vitreous pigment during this examination is the best-studied finding with the narrowest negative LR (summary LR, 0.23; 95% CI, 0.12-0.43). Patients initially diagnosed as having uncomplicated PVD have a 3.4% chance of a retinal tear within 6 weeks. The risk increases with new onset of at least 10 floaters (summary LR, 8.1-36) or subjective visual reduction (summary LR, 2.3-17) during this period. CONCLUSIONS: Primary care physicians should evaluate patients with acute-onset floaters and/or flashes due to suspected PVD, or patients with known PVD and a change in symptoms, for high-risk features of retinal tear and detachment. Physicians should always assess these patients' visual acuity. Patients at increased risk should be triaged for urgent ophthalmologic assessment.

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OBJECTIVE: To study the impact of visual impairment due to either underlying ocular pathology or easily correctable refractive error on vision-related functioning and quality of life (QOL) in Vancouver's downtown eastside (VDES). DESIGN: Cross-sectional study. PARTICIPANTS: Two hundred consecutive patients seeking general medical care at the Vancouver Native Health Society (VNHS) medical clinic were included. METHODS: An ocular examination was performed and a standardized history and QOL information were obtained for each participant. Effective visual impairment was classified based on patients' current refractive means. Pathological visual impairment was classified based on patients' best-corrected visual acuity (VA). Vision-related functioning was quantified using the Daily Tasks Dependent on Vision (DTDV) questionnaire. Health-related QOL was assessed using the 12-Item Short Form Health Survey (SF-12). RESULTS: Two hundred patients participated; they suffered, on average, 6.2 comorbid conditions. Sixty-two patients (31%) were effectively visually impaired and, of these, 14 patients (7%) were effectively blind. Ten patients (5%) had pathological eye disease to explain their visual impairment. The remaining 52 visually impaired patients (26%) had VA that normalized with correction. Difficulty with the tasks described in the DTDV questions was significantly correlated with effective visual impairment. Patients with effective visual impairment had lower Physical Composite Scores on the SF-12 in multivariate analyses. CONCLUSIONS: We have demonstrated a very high rate of visual impairment in a low socioeconomic population that is associated with decreased vision-dependent functioning and decreased overall physical health status. Public health efforts need to be directed toward improving easily correctable refractive error.

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BACKGROUND: We sought to determine whether there is a difference in in-hospital outcomes and costs for coronary artery bypass graft surgery (CABG) between the United States and Canada. METHODS: We compared the outcomes and costs of treating 12 017 consecutive patients (4698 US and 7319 Canadian patients) undergoing CABG at 5 US and 4 Canadian hospitals. Participating hospitals used the same cost accounting system to provide patient-level clinical, resource utilization, and cost-of-treatment data (excluding physicians' fees). Canadian costs were converted to US dollars using purchasing power parities. RESULTS: Compared with Canadian patients, US patients were older (mean +/- SD age, 68.0 +/- 10.4 vs 63.7 +/- 9.8 years [P<.001]), more likely to be female (27.4% vs 21.8% [P<.001]), and discharged from the hospital sooner (mean +/- SD length of stay, 8.7 +/- 0.1 vs 9.5 +/- 0.1 days [P<.001]). In-hospital costs of treatment were substantially higher in the United States than in Canada (mean +/- SD cost, dollar 20,673 +/- dollar 241 vs dollar 10,373 +/- dollar 123 [P<.001]; median, dollar 16,036 vs dollar 7880). After controlling for demographic and clinical differences, length of stay in Canada was 16.8% longer than in the United States; there was no difference in in-hospital mortality; and the cost in the United States was 82.5% higher than in Canada (P<.001). CONCLUSIONS: The in-hospital cost of CABG in the United States is substantially higher than in Canada. This difference is due to higher direct and overhead costs in US hospitals, is not explained by demographic or clinical differences, and does not lead to superior clinical outcomes.

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This paper reviews the current literature pertaining to calcium channel blockers, including their classification, properties, and therapeutic indications, in light of several recent trials that have addressed their safety. Calcium channel blockers are a structurally and functionally heterogeneous group of medications that are used widely to control blood pressure and manage symptoms of angina. They are classified as dihydropyridines or nondihydropyridines. As a class, they are well tolerated and are associated with few side effects. The question of whether they may precipitate cardiovascular events has been largely settled by recent trials, such as the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), the International Verapamil Slow-Release/Trandolapril Study (INVEST), and the Controlled Onset Verapamil Investigation of Cardiovascular Endpoints (CONVINCE) study, in which no such association was found. Even so, the use of these agents has been linked with an increased risk of heart failure. Thus, long-acting calcium channel blockers may be safely used in the management of hypertension and angina. However, as a class, they are not as protective as other antihypertensive agents against heart failure.

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BACKGROUND: Global health care costs in Canada and the United States have been examined on a macroeconomic level. However, to our knowledge, comparative costs of specific procedures in the 2 countries have not been closely studied. METHODS: To perform a microeconomic comparison of costs of open abdominal aortic aneurysm (AAA) repair, we examined the costs of treating 1057 consecutive patients from 4 Canadian (n = 552) and 6 US (n = 505) hospitals. Participating hospitals used the same cost accounting system that provided demographic, clinical, and cost data (excluding physician's fees) for each patient. Canadian dollar costs were converted to US dollar costs using purchasing power parities. RESULTS: Compared with patients who underwent AAA repair in the United States, Canadian patients were significantly younger (mean +/- SD, 70.2 +/- 10.5 vs 73.3 +/- 8.5 years; P<.001) and were less likely to undergo elective repair (48.5% vs 73.3%; P<.001). The median length of hospital stay was longer in Canada (9.0 vs 7.0 days; P<.001), and mortality rates were similar (12.0% [Canada] vs 9.9% [United States]; P =.29). The mean +/- SEM cost of AAA repair was dollars 15 852 +/- dollars 790 in Canada compared with US dollars 23299 +/- US dollars 1410 in the United States. CONCLUSIONS: The cost of AAA repair is substantially higher in the United States compared with Canada, despite shorter lengths of stay and similar clinical outcomes. The difference in total treatment costs between Canadian and American hospitals was partially attributable to differences in direct costs, but was largely due to differences in overhead costs.

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