Cost-effectiveness of breast cancer screening policies using simulation.

In this paper, we study breast cancer screening policies using computer simulation. We developed a multi-state Markov model for breast cancer progression, considering both the screening and treatment stages of breast cancer. The parameters of our model were estimated through data from the Canadian National Breast Cancer Screening Study as well as data in the relevant literature. Using computer simulation, we evaluated various screening policies to study the impact of mammography screening for age-based subpopulations in Canada. We also performed sensitivity analysis to examine the impact of certain parameters on number of deaths and total costs. The analysis comparing screening policies reveals that a policy in which women belonging to the 40-49 age group are not screened, whereas those belonging to the 50-59 and 60-69 age groups are screened once every 5 years, outperforms others with respect to cost per life saved. Our analysis also indicates that increasing the screening frequencies for the 50-59 and 60-69 age groups decrease mortality, and that the average number of deaths generally decreases with an increase in screening frequency. We found that screening annually for all age groups is associated with the highest costs per life saved. Our analysis thus reveals that cost per life saved increases with an increase in screening frequency.

An assessment of herpesvirus co-infections in patients with CMV disease: correlation with clinical and virologic outcomes.

The effect of herpesvirus co-infections (HHV-6, HHV-7) on cytomegalovirus (CMV) disease and its response to therapy is unknown. We prospectively analyzed herpesvirus co-infections in transplant recipients with CMV disease. All patients received 3 weeks of antiviral therapy. Samples were collected at baseline (day 0) and then day 3, 7, 14 and 21 poststart of therapy. Viral load testing for CMV, HHV-6 and HHV-7 was done using quantitative PCR assays in 302 patients of whom 256 had documented symptomatic CMV viremia. In this subset, day 0 HHV-6 co-infection was present in 23/253 (9.1%) and HHV-7 in 17/253 (6.7%). Including those positive at any time point raised the prevalence to 79/256 (30.9%) for HHV-6 and 75/256 (29.3%) for HHV-7. Viral co-infection did not influence the response of CMV disease to antiviral therapy. Baseline CMV viral loads, time to eradication and risk of recurrence were similar in patients with and without HHV-6 or HHV-7 co-infection. Ganciclovir and valganciclovir had no clear effect on HHV-6 and HHV-7 viremia. In conclusion, herpesvirus co-infections are common in patients with CMV disease but with standard antiviral therapy, no clear clinical effects are discernable. Routine monitoring for viral co-infection in patients with CMV disease is not indicated.

Effects of fluvastatin on cardiac events in renal transplant patients: ALERT (Assessment of Lescol in Renal Transplantation) study design and baseline data.

BACKGROUND: Recent clinical trials of primary and secondary prevention of cardiovascular disease have demonstrated that lowering plasma cholesterol with 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors ('statins') reduces morbidity and mortality from coronary heart disease in diverse patient populations. STUDY AIMS: The aim of the present ALERT (Assessment of Lescol in Renal Transplantation) study is to determine whether renal transplant recipients would also benefit from statin therapy. ALERT is a multicentre, randomized, double-blind, placebo-controlled trial to assess the effect of fluvastatin in renal transplant recipients with mild-to-moderate hypercholesterolaemia. The primary objective is to investigate the effects of fluvastatin on major adverse cardiac events (MACE). In addition, the effects on cardiovascular and all-cause mortality, as well as renal function, will be addressed. STUDY POPULATION: The study population contains patients with functioning renal allografts of more than 6 months' duration, recruited from 75 centres in Northern Europe and Canada. Patients of both sexes, aged 30-75 years, with a total cholesterol level of 4.0-9.0 mmol/l (155-348 mg/dl) were included, except for those with a history of myocardial infarction, where the upper limit for inclusion was 7.0 mmol/l (270 mg/dl). STUDY DESIGN: A total of 2100 patients were recruited by the end of October 1997 and will be followed for up to 6 years. This report presents the design features of the study (recruitment, follow-up, sample size, data analysis and study organization), along with baseline results. ALERT is the first large-scale prospective, randomized, double-blind study to address the prevention of cardiovascular mortality in renal transplant patients receiving an HMGCoA reductase inhibitor.