William W. L. Wong

Cost effectiveness of screening immigrants for hepatitis B.

Background: The prevalence of chronic hepatitis B (CHB) infection among the immigrants of North America ranges from 2 to 15%, among whom 40% develop advanced liver disease. Screening for hepatitis B surface antigen is not recommended for immigrants.

Cost-effectiveness of screening for hepatitis C in Canada

Background: The seroprevalence of hepatitis C virus (HCV) infection among Canadians is estimated at 0.3% to 0.9%. Of those with chronic HCV infection, 10% to 20% will experience advanced liver disease by 30 years of infection. Targeted screening seems a plausible strategy. We aimed to estimate the health and economic effects of various screening and treatment strategies for chronic HCV infection in Canada. Methods: We used a state-transition model to examine the cost-effectiveness of 4 screening strategies: no screening; screen and treat with pegylated interferon plus ribavarin; screen and treat with pegylated interferon and ribavarin–based direct-acting antiviral agents; and screen and treat with interferon-free direct-acting antivirals. We considered Canadian residents in 2 age groups: 25–64 and 45–64 years of age. We obtained model data from the literature. We predicted deaths related to chronic HCV infection, costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios. Results: We found that screening and treating would prevent at least 9 HCV-related deaths per 10 000 persons screened over the lifetime of the cohort. Screening was associated with QALY increases of 0.0032 to 0.0095 and cost increases of

Generalized genetic association study with samples of related individuals

124 to

Impact of Wait Times on the Effectiveness of Transcatheter Aortic Valve Replacement in Severe Aortic Valve Disease: A Discrete Event Simulation Model

338 per person, which translated to an incremental cost-effectiveness ratio of

Disease burden of chronic hepatitis B among immigrants in Canada.

34 359 to

Using Kernel Alignment to Select Features of Molecular Descriptors in a QSAR Study

44 034 per QALY gained, relative to no screening, depending on age group screened and antiviral therapy received. Interpretation: A selective one-time HCV screening program for people 25–64 or 45–64 years of age in Canada would likely be cost-effective. Identification of silent cases of chronic HCV infection and the offer of treatment when appropriate could extend the lives of Canadians at reasonable cost.

How much are we spending? The estimation of research expenditures on cardiovascular disease in Canada.

Genetic association study is an essential step to discover genetic factors that are associated with a complex trait of interest. In this paper we present a novel generalized quasi-likelihood score (GQLS) test that is suitable for a study with either a quantitative trait or a binary trait. We use a logistic regression model to link the phenotypic value of the trait to the distribution of allelic frequencies. In our model, the allele frequencies are treated as a response and the trait is treated as a covariate that allows us to leave the distribution of the trait values unspecified. Simulation studies indicate that our method is generally more powerful in comparison with the family-based association test (FBAT) and controls the type I error at the desired levels. We apply our method to analyze data on Holstein cattle for an estimated breeding value phenotype, and to analyze data from the Collaborative Study of the Genetics of Alcoholism for alcohol dependence. The results show a good portion of significant SNPs and regions consistent with previous reports in the literature, and also reveal new significant SNPs and regions that are associated with the complex trait of interest.

Drug therapies for chronic hepatitis C infection: a cost-effectiveness analysis

BACKGROUNDnThere is increasing demand for transcatheter aortic valve replacement (TAVR) as the primary treatment option for patients with severe aortic stenosis who are high-risk surgical candidates or inoperable. We used mathematical simulation models to estimate the hypothetical effectiveness of TAVR with increasing wait times.nnnMETHODSnWe applied discrete event modelling, using data from the Placement of Aortic Transcatheter Valves (PARTNER) trials. We compared TAVR with medical therapy in the inoperable cohort, and compared TAVR to conventional aortic valve surgery in the high-risk cohort. One-year mortality and wait-time deaths were calculated in different scenarios by varying TAVR wait times from 10 days to 180 days, while maintaining a constant wait time for surgery at a mean of 15.6 days.nnnRESULTSnIn the inoperable cohort, the 1-year mortality for medical therapy was 50%. When the TAVR wait time was 10 days, the TAVR wait-time mortality was 1.9% with a 1-year mortality of 31.5%. TAVR wait-time deaths increased to 28.9% with a 180-day wait, with a 1-year mortality of 41.4%. In the high-risk cohort, the wait-time deaths and 1-year mortality for the surgical patients were 2.5% and 27%, respectively. The TAVR wait-time deaths increased from 2.2% with a 10-day wait to 22.4% with a 180-day wait, and a corresponding increase in 1-year mortality from 24.5% to 32.6%. Mortality with TAVR exceeded surgery when TAVR wait times exceeded 60 days.nnnCONCLUSIONSnModest increases in TAVR wait times have a substantial effect on the effectiveness of TAVR in inoperable patients and high-risk surgical candidates.

Hepatitis B virus screening before adjuvant chemotherapy in patients with early-stage breast cancer: a cost-effectiveness analysis

BACKGROUNDnThe prevalence of chronic hepatitis B (CHB) infection among immigrants to North America ranges from 2% to 15%, 40% of whom develop advanced liver disease. Screening for hepatitis B surface antigen is not recommended for immigrants.nnnOBJECTIVEnTo estimate the disease burden of CHB among immigrants in Canada using Markov cohort models comparing a cohort of immigrants with CHB versus a control cohort of immigrants without CHB.nnnMETHODSnMarkov cohort models were used to estimate life years, quality-adjusted life years and lifetime direct medical costs (adjusted to 2008 Canadian dollars) for a cohort of immigrants with CHB living in Canada in 2006, and an age-matched control cohort of immigrants without CHB living in Canada in 2006. Parameter values were derived from the published literature.nnnRESULTSnAt the baseline estimate, the model suggested that the cohort of immigrants with CHB lost an average of 4.6 life years (corresponding to 1.5 quality-adjusted life years), had an increased average of

Cost-effectiveness of prophylactic granulocyte colony-stimulating factor for febrile neutropenia in breast cancer patients receiving FEC-D

24,249 for lifetime direct medical costs, and had a higher lifetime risk for decompensated cirrhosis (12%), hepatocellular carcinoma (16%) and need for liver transplant (5%) when compared with the control cohort.nnnDISCUSSIONnResults of the present study showed that the socio-economic burden of CHB among immigrants living in Canada is substantial. Governments and health systems need to develop policies that promote early recognition of CHB and raise public awareness regarding hepatitis B to extend the lives of infected immigrants.