Bayesian small area cluster analysis of neural tube defects in Newfoundland.

BACKGROUND: The incidence of neural tube defects (NTDs) is declining worldwide due to the implementation of folic acid supplementation programs. Such a program was implemented over 1996-97 in Newfoundland and Labrador, Canada. The geographical distribution of birth incidence was studied prior to and after the implementation of the program to identify regions of residual high incidence. Excess residual cases may potentially be due to genetic causes or incomplete supplementation program implementation. METHODS: Maternal place of residence for all provincial live birth and stillbirth notifications, provincial maternal-fetal medicine referrals, provincial rehabilitation referrals, and all provincial hospitals with NTDs or terminations for NTDs was obtained from 1975 to 2002 for near complete case ascertainment. Bayesian small area analysis was separately performed on cases from 1975-1996 and 1997-2002. The two time periods were compared. RESULTS: Birth incidence of NTDs was noted to decline after 1996, from 5.54/1000 live births to 1.08/1000 live births. 592 cases were found from 1975-1996 and 34 cases from 1997-2002. Relative risk of birth incidence was 0.93-1.18 (95% CI) for 1975-1996 and 0.97-1.02 for 1997-2002 after Bayesian smoothing. One region had an excess of residual cases greater than 34%. CONCLUSIONS: The implications of this observation to the management of the public health initiative imply that overall response to the decrease in cases tends to be uniform across the province, with potentially one area of interest where extra efforts may be devoted.

Cost-effectiveness of positron emission tomography in breast cancer.

PURPOSE: In this study, we used quantitative decision tree modeling to assess the cost-effectiveness of a positron emission tomography (PET)-based management scenario for breast cancer in Canada. PROCEDURES: Two patient management scenarios were compared (with and without PET). A metaanalysis of studies for the accuracy of PET in staging breast cancer was conducted. Life expectancies were calculated. Management costs were determined from previous cost-effective analyses, management costs from our institutions, and recently published Canadian cost estimates of various procedures. RESULTS: A cost savings of $695 per person is expected for the PET strategy, with an increase in life expectancy (7.4 days), when compared with the non-PET strategy. This cost savings remained in favor of the PET strategy when subjected to a sensitivity analysis. CONCLUSIONS: The use of a PET management strategy for the staging of breast cancer is expected to remain economically viable in Canada under various economic conditions.

A quantitative review of the use of FDG-PET in the axillary staging of breast cancer.

Breast cancer is the most frequent type of cancer in women and is the second leading cause of cancer death in Canadian women. It is an important source of morbidity and mortality in today's society and confers risk to the patient both in terms of the disease itself and the treatment of the disease. Axillary lymph node status is the most important prognostic factor for determining breast cancer survival and it guides the treatment of the disease based on the disease stage. The aim of this study is to assess the diagnostic value of positron emission tomography (PET) utilizing [18F]2-fluoro-2-deoxy-D-glucose (FDG) in the axillary staging of breast cancer. A systematic literature search was carried out in the Medline, Embase and Cochrane databases. Seventy one original studies were identified, 20 of which evaluated the axillary status of women. The studies were graded based on recommended procedures from similar studies. Aggregate sensitivities and specificities were calculated for various levels of quality for all included studies. Recommendations for future studies were made based on patient positioning, acquisition time, attenuation correction, fasting state, and image interpretation. A large variation in the sensitivity and specificity of large diagnostic trials of similar quality was noted. We concluded that PET has promise for the axillary staging of breast cancer once the variability of sensitivity and specificity in these large trials is addressed.

Cost effectiveness of positron emission tomography in Canada.

BACKGROUND: Positron emission tomography (PET) has been shown to be cost effective for the staging of stage I and II breast cancer, recurrent colorectal cancer and non small cell lung cancer. This study determines a required catchment size for the management of these three cancers based on a breakeven analysis. MATERIAL/METHODS: Cost effectiveness analysis is used to determine the cost savings of introducing PET into the diagnostic algorithm for the staging of stage I and II breast cancer, recurrent colorectal cancer and non small cell lung cancer. The cost savings for these cancers are used to calculate a required catchment area for the installation of a PET center with cyclotron. RESULTS: The aggregate estimated "breakeven" cost of a PET study would be dollars 2195, well below the expected cost per study. In order to break even, each PET device would require 740 new cases per year. For a general representative population, one person per 766 may benefit from a PET scan if a PET study was included in the diagnostic algorithm for all three cancers. Finally, a calculated catchment size of 567,000 people would support the use of a PET center with cyclotron CONCLUSIONS: The use of PET for the staging of cancer appears to be cost effective in most jurisdictions in Canada.

Cost-effectiveness of positron emission tomography for non-small cell lung carcinoma in Canada.

BACKGROUND: Several studies over the past decade have demonstrated that 2-fluoro-2-D-[18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is more accurate than computed tomography (CT) for the staging of non-small cell lung carcinoma (NSCLC). This study uses quantitative decision tree modeling and sensitivity analysis to assess the cost-effectiveness of both a CT- and a CT+PET-based management strategy for staging NSCLC in Canada. Both management costs and life expectancy are determined. MATERIAL/METHODS: Two patient management scenarios were compared--one using CT alone and one using both CT and PET. A survey of recent literature was used to construct a meta-analysis of available studies for the accuracies of CT and PET in staging NSCLC. Life expectancies were determined from recent Canadian statistics, and expected life expectancies with disease were calculated from knowledge of published survival rates. Management costs were determined from: estimates of the installation cost of PET facilities in Canada; management costs from our institutions; and recently published Canadian cost estimates of various procedures. RESULTS: A cost savings of 1455 Canadian dollars per person is expected for the CT+PET strategy, along with an increase in life expectancy (3.1 days), when compared with the CT alone strategy. This cost savings remained in favour of the CT+PET strategy when subjected to a rigorous sensitivity analysis. CONCLUSIONS: PET may be a cost effective means of staging NSCLC in Canada.