Learn More
BACKGROUND Providers have been reluctant to disclose patient data for public-health purposes. Even if patient privacy is ensured, the desire to protect provider confidentiality has been an important driver of this reluctance. METHODS Six requirements for a surveillance protocol were defined that satisfy the confidentiality needs of providers and ensure(More)
BACKGROUND A systematic review was conducted to evaluate the literature regarding the impact of follow-up on colorectal cancer patient survival and, in a second phase, recommendations were developed. METHODS The MEDLINE, CANCERLIT, and Cochrane Library databases, and abstracts published in the 1997 to 2002 proceedings of the annual meeting of the American(More)
BACKGROUND There is limited capacity to assess the comparative risks of medications after they enter the market. For rare adverse events, the pooling of data from multiple sources is necessary to have the power and sufficient population heterogeneity to detect differences in safety and effectiveness in genetic, ethnic and clinically defined subpopulations.(More)
BACKGROUND The purpose of this study was to estimate the relative impact of changes in demographics, stage at detection, treatment mix, and medical technology on 5-year survival among older colorectal cancer (CRC) patients. METHODS We selected older patients diagnosed with CRC between 1992 and 2000 from the SEER-Medicare database and followed them through(More)
OBJECTIVE To evaluate measures that could use existing administrative data to assess the intensity of end-of-life cancer care. METHODS Benchmarking standards and statistical variation were evaluated using Medicare claims of 48,906 patients who died from cancer from 1991 through 1996 in 11 regions of the United States. We assessed accuracy by comparing(More)
To determine the accuracy with which Medicare claims data measure disease-free survival in elderly Medicare beneficiaries with cancer, we performed a criterion validation study. We merged gold-standard clinical trial data of 45 elderly patients with node-positive breast cancer who were treated on the Cancer and Leukemia Group B (CALGB) adjuvant breast trial(More)
OBJECTIVE  To determine the association between vasectomy and prostate cancer, adjusting for measures of health seeking behaviour. DESIGN  Population based matched cohort study. SETTING  Multiple validated healthcare databases in Ontario, Canada, 1994-2012. PARTICIPANTS  326 607 men aged 20 to 65 who had undergone vasectomy were identified through(More)
BACKGROUND Overuse of anti-cancer therapy is an important quality-of-care issue. An aggressive approach to treatment can have negative effects on quality of life and cost, but its effect on survival is not well-defined. METHODS Using the Surveillance, Epidemiology, and End Results-Medicare database, we identified 7,879 Medicare-enrolled patients aged 65(More)
BACKGROUND Clinical practice guidelines recommend colonoscopies at regular intervals for colorectal cancer (CRC) survivors. Using data from a large, multi-regional, population-based cohort, we describe the rate of surveillance colonoscopy and its association with geographic, sociodemographic, clinical, and health services characteristics. METHODS We(More)
OBJECTIVES To determine if the length of interval between breast conserving surgery and start of radiotherapy affects local recurrence and to identify factors that might be associated with delay in older women with breast cancer. DESIGN Retrospective cohort analysis with Cox proportional hazards models to study the association between time to radiotherapy(More)