Cost-effectiveness of screening with contrast enhanced magnetic resonance imaging vs X-ray mammography of women at a high familial risk of breast cancer

Contrast enhanced magnetic resonance imaging (CE MRI) is the most sensitive tool for screening women who are at high familial risk of breast cancer. Our aim in this study was to assess the cost-effectiveness of X-ray mammography (XRM), CE MRI or both strategies combined. In total, 649 women were enrolled in the MARIBS study and screened with both CE MRI and mammography resulting in 1881 screens and 1-7 individual annual screening events. Women aged 35-49 years at high risk of breast cancer, either because they have a strong family history of breast cancer or are tested carriers of a BRCA1, BRCA2 or TP53 mutation or are at a 50% risk of having inherited such a mutation, were recruited from 22 centres and offered annual MRI and XRM for between 2 and 7 years. Information on the number and type of further investigations was collected and specifically calculated unit costs were used to calculate the incremental cost per cancer detected. The numbers of cancer detected was 13 for mammography, 27 for CE MRI and 33 for mammography and CE MRI combined. In the subgroup of BRCA1 (BRCA2) mutation carriers or of women having a first degree relative with a mutation in BRCA1 (BRCA2) corresponding numbers were 3 (6), 12 (7) and 12 (11), respectively. For all women, the incremental cost per cancer detected with CE MRI and mammography combined was 28 pound 284 compared to mammography. When only BRCA1 or the BRCA2 groups were considered, this cost would be reduced to 11 pound 731 (CE MRI vs mammography) and 15 pound 302 (CE MRI and mammography vs mammography). Results were most sensitive to the unit cost estimate for a CE MRI screening test. Contrast-enhanced MRI might be a cost-effective screening modality for women at high risk, particularly for the BRCA1 and BRCA2 subgroups. Further work is needed to assess the impact of screening on mortality and health-related quality of life.

Host-dependent Anopheles flavirostris larval distribution reinforces the risk of malaria near water

Malaria control strategies are more likely to be successful if groups at high risk can be accurately predicted. Given that mosquitoes have an obligate aquatic phase we were interested in determining how vector larval abundance relates to the spatial distribution of human malaria infection. We examined the relationship between malaria parasite prevalence and distance from vector larval habitat, and vector larval abundance and distance from human habitation, in separate studies in rural, low-endemic areas of the Philippines. Parasite prevalence among symptomatic patients was significantly higher among those living in proximity ( less than or equal to 50 m) to potential larval habitats of the major vector, Anopheles flavirostris (adjusted odds ratio [AOR] 2.64, P = 0.02 and AOR 3.43, P = 0.04). A larval survey of A. flavirostris revealed a higher density of early and late instars near human habitation (adjusted P < 0.05). The results suggest that larvae are associated with human habitation, thereby reinforcing malaria risk in people living close to larval habitats. This has implications for understanding the interaction between vectors, hosts, and parasites, and the potential for success of localized malaria control measures.

Carotid artery intimal medial thickness, brachial artery flow-mediated vasodilation and cardiovascular risk factors in diabetic and non-diabetic indigenous Australians

Background: Indigenous Australians are at high risk for cardiovascular disease and type 2 diabetes. Carotid artery intimal medial thickness (CIMT) and brachial artery flow-mediated vasodilation (FMD) are ultrasound imaging based surrogate markers of cardiovascular risk. This study examines the relative contributions of traditional cardiovascular risk factors on CIMT and FMD in adult Indigenous Australians with and without type 2 diabetes mellitus. Method: One hundred and nineteen Indigenous Australians were recruited. Physical and biochemical markers of cardiovascular risk, together with CIMT and FMD were meausred for all subjects. Results: Fifty-three Indigenous Australians subjects (45%) had type 2 diabetes mellitus. There was a significantly greater mean CIMT in diabetic versus non-diabetic subjects (p = 0.049). In the non-diabetic group with non-parametric analyses, there were significant correlations between CIMT and: age (r = 0.64, p < 0.001), systolic blood pressure (r = 0.47, p < 0.001) and non-smokers (r = -0.30, p = 0.018). In the diabetic group, non-parametric analysis showed correlations between CIMT, age (r = 0.36, p = 0.009) and duration of diabetes (r = 0.30, p = 0.035) only. Adjusting forage, sex, smoking and history of cardiovascular disease, Hb(A1c) became the sole significant correlate of CIMT (r = 0.35,p = 0.01) in the diabetic group. In non-parametric analysis, age was the sole significant correlate of FMD (r = -0.31,p = 0.013), and only in non-diabetic subjects. Linear regression analysis showed significant associations between CIMT and age (t = 4.6,p < 0.001), systolic blood pressure (t = 2.6, p = 0.010) and Hb(A1c) (t = 2.6, p = 0.012), smoking (t = 2.1, p = 0.04) and fasting LDL-cholesterol (t = 2.1, p = 0.04). There were no significant associations between FMD and examined cardiovascular risk factors with linear regression analysis Conclusions: CIMT appears to be a useful surrogate marker of cardiovascular risk in this sample of Indigenous Australian subjects, correlating better than FMD with established cardiovascular risk factors. A lifestyle intervention programme may alleviate the burden of cardiovascular disease in Indigenous Australians by reducing central obesity, lowering blood pressure, correcting dyslipidaemia and improving glycaemic control. CIMT may prove to be a useful tool to assess efficacy of such an intervention programme. (c) 2004 Elsevier Ireland Ltd. All rights reserved.

Disease risk and mortality prediction in intensive care patients with pneumonia. Australian and New Zealand practice in intensive care (ANZPIC II)

This study of ventilated patients investigated pneumonia risk factors and outcome predictors in 476 episodes of pneumonia (48% community-acquired pneumonia, 24% hospital-acquired pneumonia, 28% ventilator-associated pneumonia) using a prospective survey in 14 intensive care units within Australia and New Zealand. For community acquired pneumonia, mortality increased with immunosuppression (OR 5.32, CI 95% 1.58-17.99, P < 0. 01), clinical signs of consolidation (OR 2.43, CI 95% 1.09-5.44, P = 0. 03) and Sepsis-Related Organ Failure Assessment (SOFA) scores (OR 1.19, CI 95% 1.08-1.30, P < 0. 001) but improved if appropriate antibiotic changes were made within three days of intensive care unit admission (OR 0.42, CI 95% 0.20-0.86, P = 0.02). For hospital-acquired pneumonia, immunosuppression (OR 6.98, CI 95% 1.16-42.2, P = 0.03) and non-metastatic cancer (OR 3.78, CI 95% 1.20-11.93, P = 0.02) were the principal mortality predictors. Alcoholism (OR 7.80, CI 95% 1.20-1750, P < 0.001), high SOFA scores (OR 1.44, CI 95% 1.20-1.75, P = 0.001) and the isolation of high risk organisms including Pseudomonas aeruginosa, Acinetobacter spp, Stenotrophomonas spp and methicillin resistant Staphylococcus aureus (OR 4.79, CI 95% 1.43-16.03, P = 0.01), were associated with increased mortality in ventilator-associated pneumonia. The use of non-invasive ventilation was independently protective against mortality for patients with community-acquired and hospital-acquired pneumonia (OR 0.35, CI 95% 0.18-0.68, P = 0.002). Mortality was similar for patients requiting both invasive and non-invasive ventilation and non-invasive ventilation alone (21% compared with 20% respectively, P = 0.56). Pneumonia risks and mortality predictors in Australian and New Zealand ICUs vary with pneumonia type. A history of alcoholism is a major risk factor for mortality in ventilator-associated pneumonia, greater in magnitude than the mortality effect of immunosuppression in hospital-acquired pneumonia or community-acquired pneumonia. Non-invasive ventilation is associated with reduced ICU mortality. Clinical signs of consolidation worsen, while rationalising antibiotic therapy within three days of ICU admission improves mortality for community-acquired pneumonia patients.

The consistency of extinction risk classification protocols

Systematic protocols that use decision rules or scores arc, seen to improve consistency and transparency in classifying the conservation status of species. When applying these protocols, assessors are typically required to decide on estimates for attributes That are inherently uncertain, Input data and resulting classifications are usually treated as though they arc, exact and hence without operator error We investigated the impact of data interpretation on the consistency of protocols of extinction risk classifications and diagnosed causes of discrepancies when they occurred. We tested three widely used systematic classification protocols employed by the World Conservation Union, NatureServe, and the Florida Fish and Wildlife Conservation Commission. We provided 18 assessors with identical information for 13 different species to infer estimates for each of the required parameters for the three protocols. The threat classification of several of the species varied from low risk to high risk, depending on who did the assessment. This occurred across the three Protocols investigated. Assessors tended to agree on their placement of species in the highest (50-70%) and lowest risk categories (20-40%), but There was poor agreement on which species should be placed in the intermediate categories, Furthermore, the correspondence between The three classification methods was unpredictable, with large variation among assessors. These results highlight the importance of peer review and consensus among multiple assessors in species classifications and the need to be cautious with assessments carried out 4), a single assessor Greater consistency among assessors requires wide use of training manuals and formal methods for estimating parameters that allow uncertainties to be represented, carried through chains of calculations, and reported transparently.

Kidney and related chronic disease profiles and risk factors in three remote Australian Aboriginal communities

Morbidities and deaths from noncommunicable chronic diseases are greatly increased in remote Australian Aboriginal communities, but little is known of the underlying community-based health profiles. We describe chronic-disease profiles and their risk factors in 3 remote communities in the Northern Territory. Consenting adults (18+ years of age) in 3 communities participated in a brief history and examination between 2000 and mid-2003 as part of a systematic program to improve chronic-disease awareness and management. Participation was 67%,128%, and 62% in communities A, B, and C, respectively with a total of 1070 people examined. Current smokers included 41% of females and 72% of males. Most men were current drinkers, but most women were not. Parameters of body weight differed markedly by community, with mean body mass index (BMC) varying from 21.4 to 27.9 kg/m(2). Rates of chronic diseases were excessive but differed markedly; an almost threefold difference in the likelihood of any morbidity existed between communities A and C. Rates increased with age, but the greatest numbers of people with morbidities were in the middle-aged group. Most people had multiple morbidities with tremendous overlap. Hypertension and kidney disease appear to be early manifestations of the integrated chronic-disease syndrome, while diabetes is a late manifestation or complication. Substantial numbers of new cases of disease were identified by testing, and blood pressure improved in treated people with hypertension. Wide variations occur in body habitus, risk factors, and chronic-disease rates among communities, but an overwhelming need for effective smoking interventions exists in all. Systematic screening is useful in identifying high-risk individuals, most at early treatable stages there. Findings are very important for estimating current treatment needs, future burdens of disease, and for needs-based health services planning. Resources required will vary according to the burden of disease. (C) 2005 by the National Kidney Foundation, Inc.

Risk stratification of patients with chronic kidney disease: Results of screening strategies incorporating clinical risk scoring and dobutamine stress echocardiography

Background Cardiac disease is the principal cause of death in patients with chronic kidney disease (CKD). Ischemia at dobutamine stress echocardiography (DSE) is associated with adverse events in these patients. We sought the efficacy of combining clinical risk evaluation with DSE. Methods We allocated 244 patients with CKD (mean age 54 years, 140 men, 169 dialysis-dependent at baseline) into low- and high-risk groups based on two disease-specific scores and the Framingham risk model. All underwent DSE and were further stratified according to DSE results. Patients were followed over 20 +/- 14 months for events (death, myocardial infarction, acute coronary syndrome). Results There were 49 deaths and 32 cardiac events. Using the different clinical scores, allocation of high risk varied from 34% to 79% of patients, and 39% to 50% of high-risk patients had an abnormal DSE. In the high-risk groups, depending on the clinical score chosen, 25% to 44% with an abnormal DSE had a cardiac event, compared with 8% to 22% with a.normal DSE. Cardiac events occurred in 2.0%, 3.1 %, and 9.7% of the low-risk patients, using the two disease-specific and Framingham scores, respectively, and DSE results did not add to risk evaluation in this subgroup. Independent DSE predictors of cardiac events were a lower resting diastolic blood pressure, angina during the test, and the combination of ischemia with resting left ventricular dysfunction. Conclusion In CKD patients, high-risk findings by DSE can predict outcome. A stepwise strategy of combining clinical risk scores with DSE for CAD screening in CKD reduces the number of tests required and identifies a high-risk subgroup among whom DSE results more effectively stratify high and low risk.